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Sample records for adventitious root development

  1. Adventitious Roots and Secondary Metabolism

    Institute of Scientific and Technical Information of China (English)

    Hosakatte Niranjana Murthy; Eun Joo Hahn; Kee Yoeup Paek

    2008-01-01

    Plants are a rich source of valuable secondary metabolites and in the recent years plant cell, tissue and organ cultures have been developed as an important alternative sources for the production of these compounds. Adventitious roots have been successfully induced in many plant species and cultured for the production of high value secondary metabolites of pharmaceutical, nutraceutical and industrial importance. Adoption of elicitation methods have shown improved synthesis of secondary metabolites in adventitious root cultures. Development of large-scale culture methods using bioreactors has opened up feasibilities of production of secondary metabolites at the industrial levels. In the present review we summarize the progress made in recent past in the area of adventitious root cultures for the production of secondary metabolites.

  2. Nutrition and adventitious rooting in woody plants

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    Fernanda Bortolanza Pereira

    2016-09-01

    Full Text Available Vegetative propagation success of commercial genotypes via cutting techniques is related to several factors, including nutritional status of mother trees and of propagation material. The nutritional status determines the carbohydrate quantities, auxins and other compounds of plant essential metabolism for root initiation and development. Each nutrient has specific functions in plant, acting on plant structure or on plant physiology. Although the importance of mineral nutrition for success of woody plants vegetative propagation and its relation with adventitious rooting is recognized, the role of some mineral nutrients is still unknown. Due to biochemical and physiological complexity of adventitious rooting process, there are few researches to determine de role of nutrients on development of adventitious roots. This review intends to explore de state of the art about the effect of mineral nutrition on adventitious rooting of woody plants.

  3. Proteomic Analysis of Different Mutant Genotypes of Arabidopsis Led to the Identification of 11 Proteins Correlating with Adventitious Root Development1[W

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    Sorin, Céline; Negroni, Luc; Balliau, Thierry; Corti, Hélène; Jacquemot, Marie-Pierre; Davanture, Marlène; Sandberg, Göran; Zivy, Michel; Bellini, Catherine

    2006-01-01

    A lack of competence to form adventitious roots by cuttings or explants in vitro occurs routinely and is an obstacle for the clonal propagation and rapid fixation of elite genotypes. Adventitious rooting is known to be a quantitative genetic trait. We performed a proteomic analysis of Arabidopsis (Arabidopsis thaliana) mutants affected in their ability to develop adventitious roots in order to identify associated molecular markers that could be used to select genotypes for their rooting ability and/or to get further insight into the molecular mechanisms controlling adventitious rooting. Comparison of two-dimensional gel electrophoresis protein profiles resulted in the identification of 11 proteins whose abundance could be either positively or negatively correlated with endogenous auxin content, the number of adventitious root primordia, and/or the number of mature adventitious roots. One protein was negatively correlated only to the number of root primordia and two were negatively correlated to the number of mature adventitious roots. Two putative chaperone proteins were positively correlated only to the number of primordia, and, interestingly, three auxin-inducible GH3-like proteins were positively correlated with the number of mature adventitious roots. The others were correlated with more than one parameter. The 11 proteins are predicted to be involved in different biological processes, including the regulation of auxin homeostasis and light-associated metabolic pathways. The results identify regulatory pathways associated with adventitious root formation and represent valuable markers that might be used for the future identification of genotypes with better rooting abilities. PMID:16377752

  4. Rapid flooding-induced adventitious root development from preformed primordia in Solanum dulcamara

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    Dawood, Thikra; Rieu, Ivo; Wolters-Arts, Mieke; Derksen, Emiel B.; Mariani, Celestina; Visser, Eric J. W.

    2013-01-01

    Flooding is a common stress factor in both natural and agricultural systems, and affects plant growth by the slow diffusion rate of gases in water. This results in low oxygen concentrations in submerged tissues, and hence in a decreased respiration rate. Understanding the responses of plants to flooding is essential for the management of wetland ecosystems, and may benefit research to improve the flood tolerance of crop species. This study describes the response to partial submergence of bittersweet (Solanum dulcamara). Bittersweet is a Eurasian species that grows both in dry habitats such as coastal dunes, and in wetlands, and therefore is a suitable model plant for studying responses to a variety of environmental stresses. A further advantage is that the species is closely related to flood-intolerant crops such as tomato and eggplant. The species constitutively develops dormant primordia on the stem, which we show to have a predetermined root identity. We investigated adventitious root growth from these primordia during flooding. The synchronized growth of roots from the primordia was detected after 2–3 days of flooding and was due to a combination of cell division and cell elongation. Gene expression analysis demonstrated that the molecular response to flooding began within 2 h and included activation of hypoxia and ethylene signalling genes. Unexpectedly, these early changes in gene expression were very similar in primordia and adjacent stem tissue, suggesting that there is a dominant general response in tissues during early flooding. PMID:24790121

  5. Change of Nitric Oxide and NADPH-diaphorase During the Generation and the Development of Adventitious Roots in Mung Bean Hypocotyl Cuttings

    Institute of Scientific and Technical Information of China (English)

    SHEXiao-Ping; HUANGAi-Xia

    2004-01-01

    Effects of nitric oxide (NO) donor sodium nitroprusside (SNP), NO specific scavenger c-PTIO and nitric oxide synthase (NOS) inhibitor L-NAME on the rooting of mung bean ( Vigna radiata L.) hypocotyl cuttings were studied. The spatio-temporal changes of NO and NADPH-diaphorase in the basal part of cutting were also detected during the adventitious rooting process. The results showed that SNP significantly enhanced the adventitious rooting in the range of concentrations tested. NADPH-diaphorase activity (commonly employed as a marker for NOS) and the fluorescence of NO were respectively observed in the zone between the vascular bundles of the basal part of cuttings at 24h and 36h after cutting. The root primordium became discernible at 48h after cutting in the same region, and became more elongate at 60h. NADPH-diaphorase activity and NO fluorescence gradually increased during 48-60h and mainly distributed in root meristem. L-NAME treatment delayed adventitious root emergency and significantly reduced the NADPH-diaphorase staining and the fluorescence of NO. The specific NO scavenger, c-PTIO, also suppressed the fluorescence and inhibited the formation of adventitious roots. These results suggest that endogenous NO appears to play a key role in the generation and development of adventitious roots, and the production of NO in this process may be catalyzed by NOS-like enzyme.

  6. Molecular cloning, characterization and expression analysis of the SAMS gene during adventitious root development in IBA-induced tetraploid black locust.

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    Quan, Jine; Zhang, Sheng; Zhang, Chunxia; Meng, Sen; Zhao, Zhong; Xu, Xuexuan

    2014-01-01

    S-Adenosylmethionine synthetase (SAMS) catalyzes the synthesis of S-adenosylmethionine (SAM), a precursor for ethylene and polyamine biosynthesis. Here, we report the isolation of the 1498 bp full-length cDNA sequence encoding tetraploid black locust (Robinia pseudoacacia L.) SAMS (TrbSAMS), which contains an open reading frame of 1179 bp encoding 392 amino acids. The amino acid sequence of TrbSAMS has more than 94% sequence identity to SAMSs from other plants, with a closer phylogenetic relationship to SAMSs from legumes than to SAMS from other plants. The TrbSAMS monomer consists of N-terminal, central, and C-terminal domains. Subcellular localization analysis revealed that the TrbSAMS protein localizes mainly to in the cell membrane and cytoplasm of onion epidermal cells and Arabidopsis mesophyll cell protoplasts. Indole-3-butyric acid (IBA)-treated cuttings showed higher levels of TrbSAMS transcript than untreated control cuttings during root primordium and adventitious root formation. TrbSAMS and its downstream genes showed differential expression in shoots, leaves, bark, and roots, with the highest expression observed in bark. IBA-treated cuttings also showed higher SAMS activity than control cuttings during root primordium and adventitious root formation. These results indicate that TrbSAMS might play an important role in the regulation of IBA-induced adventitious root development in tetraploid black locust cuttings.

  7. Transcriptome profiling and comparative analysis of Panax ginseng adventitious roots

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    Murukarthick Jayakodi

    2014-10-01

    Conclusion: This study will provide a comprehensive insight into the transcriptome of ginseng adventitious roots, and a way for successful transcriptome analysis and profiling of resource plants with less genomic information. The transcriptome profiling data generated in this study are available in our newly created adventitious root transcriptome database (http://im-crop.snu.ac.kr/transdb/index.php for public use.

  8. Effect of sucrose on adventitious root regeneration in apple

    NARCIS (Netherlands)

    Calamar, A.; Klerk, de G.J.M.

    2002-01-01

    We have examined the effect of sucrose on adventitious root formation in apple microcuttings and in 1-mm stem slices cut from apple microcuttings. The sucrose concentration influenced the number of adventitious roots, but at a broad range of sucrose concentrations (1¿9%) the effect was small. In add

  9. Influence of light and shoot development stage on leaf photosynthesis and carbohydrate status during the adventitious root formation in cuttings of Corylus avellana L.

    Directory of Open Access Journals (Sweden)

    Sergio eTombesi

    2015-11-01

    Full Text Available Adventitious root formation in plant cuttings is influenced by many endogenous and environmental factors. Leaf photosynthesis during rooting of leafy cuttings in hard to root species can contribute to supply carbohydrates to the intensive metabolic processes related to adventious root formation. Light intensity during rooting is artificially kept low to decrease potential cutting desiccation, but can be limiting for photosynthetic activity. Furthermore, leafy cuttings collected from different part of the shoot can have a different ability to fuel adventitious root formation in cutting stem. The aim of this work was to determine the role of leaf photosynthesis on adventitious root formation in hazelnut (Corylus avellana L (a hard-to-root specie leafy cuttings and to investigate the possible influence of the shoot developmental stage on cutting rooting and survival in the post-rooting phase. Cutting rooting was closely related to carbohydrate content in cutting stems during the rooting process. Cutting carbohydrate status was positively influenced by leaf photosynthesis during rooting. Non saturating light exposure of leafy cuttings can contribute to improve photosynthetic activity of leafy cuttings. Collection of cuttings from different part of the mother shoots influenced rooting percentage and this appear related to the different capability to concentrate soluble sugars in the cutting stem during rooting. Adventitious root formation depend on the carbohydrate accumulation at the base of the cutting. Mother shoot developmental stage and leaf photosynthesis appear pivotal factors for adventitious roots formation.

  10. Expressed sequence tag analysis of functional genes associated with adventitious rooting in Liriodendron hybrids.

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    Zhong, Y D; Sun, X Y; Liu, E Y; Li, Y Q; Gao, Z; Yu, F X

    2016-06-24

    Liriodendron hybrids (Liriodendron chinense x L. tulipifera) are important landscaping and afforestation hardwood trees. To date, little genomic research on adventitious rooting has been reported in these hybrids, as well as in the genus Liriodendron. In the present study, we used adventitious roots to construct the first cDNA library for Liriodendron hybrids. A total of 5176 expressed sequence tags (ESTs) were generated and clustered into 2921 unigenes. Among these unigenes, 2547 had significant homology to the non-redundant protein database representing a wide variety of putative functions. Homologs of these genes regulated many aspects of adventitious rooting, including those for auxin signal transduction and root hair development. Results of quantitative real-time polymerase chain reaction showed that AUX1, IRE, and FB1 were highly expressed in adventitious roots and the expression of AUX1, ARF1, NAC1, RHD1, and IRE increased during the development of adventitious roots. Additionally, 181 simple sequence repeats were identified from 166 ESTs and more than 91.16% of these were dinucleotide and trinucleotide repeats. To the best of our knowledge, the present study reports the identification of the genes associated with adventitious rooting in the genus Liriodendron for the first time and provides a valuable resource for future genomic studies. Expression analysis of selected genes could allow us to identify regulatory genes that may be essential for adventitious rooting.

  11. Role of adventitious roots in water relations of tamarack (Larix laricina seedlings exposed to flooding

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    Calvo-Polanco Mónica

    2012-06-01

    Full Text Available Abstract Background Flooding reduces supply of oxygen to the roots affecting plant water uptake. Some flooding-tolerant tree species including tamarack (Larix laricina (Du Roi K. Koch produce adventitious roots in response to flooding. These roots were reported to have higher hydraulic conductivity under flooding conditions compared with non-adventitious roots. In the present study, we examined structural and functional modifications in adventitious roots of tamarack seedlings to explain their flooding tolerance. Results Seedlings were subjected to the flooding treatment for six months, which resulted in an almost complete disintegration of the existing root system and its replacement with adventitious roots. We compared gas exchange parameters and water relations of flooded plants with the plants growing in well-drained soil and examined the root structures and root water transport properties. Although flooded seedlings had lower needle chlorophyll concentrations, their stomatal conductance, net photosynthesis rates and shoot water potentials were similar to non-flooded plants, indicative of flooding tolerance. Flooded adventitious roots had higher activation energy and a higher ratio of apoplastic to cell-to-cell water flow compared with non-flooded control roots as determined with the 1-hydroxypirene 3,6,8-trisulfonic acid apoplastic tracer dye. The adventitious roots in flooded plants also exhibited retarded xylem and endodermal development and accumulated numerous starch grains in the cortex. Microscopic examination of root sections treated with the PIP1 and PIP2 antibodies revealed high immunoreactivity in the cortex of non-flooded roots, as compared with flooded roots. Conclusions Structural modifications of adventitious roots suggest increased contribution of apoplastic bypass to water flow. The reduced dependence of roots on the hypoxia-sensitive aquaporin-mediated water transport is likely among the main mechanisms allowing tamarack

  12. Dynamics of gibberellin-like substances in the development of buds, newly formed shoots and adventitious roots of willow cuttings(Salix viminalis L.

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    M. Michniewicz

    2015-01-01

    Full Text Available It was stated that adventitious roots as well as shoots formed from the buds of willow cuttings contained two GA-like substances. One of them was different in roots and in shoots. The amount of Ga-like substance in roots was much higher than in shoots. The level of these substances increased very intensively in roots while in shoots rather slightly and only in the earlier stages of their growth. The results of later experiments and of others presented here shown that adventitious roots of willow cuttings are the sites of gibberellin biosynthesis. Possible explanation of existing of different gibberellins in roots and in shoots is also discussed.

  13. Mineral nutrition and adventitious rooting in microcuttings of Eucalyptus globulus.

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    Schwambach, Joséli; Fadanelli, Cristina; Fett-Neto, Arthur G

    2005-04-01

    We characterized the adventitious rooting response of Eucalyptus globulus Labill. to various concentrations of calcium, nitrogen, phosphorus, iron, manganese, zinc, boron and copper. The parameters analyzed were percent rooting, root number, root length and mean rooting time. Root number and root length were significantly affected by mineral nutrition, whereas mean rooting time and rooting percentage seemed to be closely related to auxin availability. Root number was affected by calcium, nitrogen source and zinc, whereas root length was influenced by concentrations of phosphorus, iron and manganese, and by nitrogen source. Based on these results, we evaluated various combinations of several concentrations of these minerals in each rooting phase. Cuttings that were rooted in an optimized mineral nutrient medium and acclimatized to ex-vitro conditions for two months showed significantly higher survival after transplanting and drought stress than cuttings rooted in basal medium and treated in the same way.

  14. Quantitative Analysis of Adventitious Root Growth Phenotypes in Carnation Stem Cuttings.

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    Birlanga, Virginia; Villanova, Joan; Cano, Antonio; Cano, Emilio A; Acosta, Manuel; Pérez-Pérez, José Manuel

    2015-01-01

    Carnation is one of the most important species on the worldwide market of cut flowers. Commercial carnation cultivars are vegetatively propagated from terminal stem cuttings that undergo a rooting and acclimation process. For some of the new cultivars that are being developed by ornamental breeders, poor adventitious root (AR) formation limits its commercial scaling-up, due to a significant increase in the production costs. We have initiated a genetical-genomics approach to determine the molecular basis of the differences found between carnation cultivars during adventitious rooting. The detailed characterization of AR formation in several carnation cultivars differing in their rooting losses has been performed (i) during commercial production at a breeders' rooting station and (ii) on a defined media in a controlled environment. Our study reveals the phenotypic signatures that distinguishes the bad-rooting cultivars and provides the appropriate set-up for the molecular identification of the genes involved in AR development in this species.

  15. Quantitative Analysis of Adventitious Root Growth Phenotypes in Carnation Stem Cuttings.

    Directory of Open Access Journals (Sweden)

    Virginia Birlanga

    Full Text Available Carnation is one of the most important species on the worldwide market of cut flowers. Commercial carnation cultivars are vegetatively propagated from terminal stem cuttings that undergo a rooting and acclimation process. For some of the new cultivars that are being developed by ornamental breeders, poor adventitious root (AR formation limits its commercial scaling-up, due to a significant increase in the production costs. We have initiated a genetical-genomics approach to determine the molecular basis of the differences found between carnation cultivars during adventitious rooting. The detailed characterization of AR formation in several carnation cultivars differing in their rooting losses has been performed (i during commercial production at a breeders' rooting station and (ii on a defined media in a controlled environment. Our study reveals the phenotypic signatures that distinguishes the bad-rooting cultivars and provides the appropriate set-up for the molecular identification of the genes involved in AR development in this species.

  16. Seminal, adventitious and lateral root growth and physiological responses in rice to upland conditions

    Institute of Scientific and Technical Information of China (English)

    杨玲; 郑炳松; 毛传澡; 易可可; 吴运荣; 吴平; 陶勤南

    2003-01-01

    Understanding the growth and physiological responses of rice to upland conditions would be helpful for designing treatments to improve the tolerance of rice under a rainfed system. The objective of this study was to investigate the initiation,elongation and membrane stability of seminal, lateral and adventitious roots of upland rice after 9-d upland condition treatment. Compared with control roots under waterlogged conditions, upland water deficiency conditions favor seminal and lateral root growth over adventitious root growth by accelerating seminal root elongation, promoting lateral root initiation and elongation, and reducing the elongation and number of adventitious roots. Enhanced total root number and length resulted in increase of total root dry weight and thereby increasing the root-to-shoot ratio. Organic compound leakage from seminal root tips and adventitious roots increased progressively to some extent with upland culture duration, while significant increases in seminal root tips were the consequence of loss of membrane integrity caused by the upland-condition enhanced growth.

  17. Gibberellins inhibit adventitious rooting in hybrid aspen and Arabidopsis by affecting auxin transport.

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    Mauriat, Mélanie; Petterle, Anna; Bellini, Catherine; Moritz, Thomas

    2014-05-01

    Knowledge of processes involved in adventitious rooting is important to improve both fundamental understanding of plant physiology and the propagation of numerous plants. Hybrid aspen (Populus tremula × tremuloïdes) plants overexpressing a key gibberellin (GA) biosynthesis gene (AtGA20ox1) grow rapidly but have poor rooting efficiency, which restricts their clonal propagation. Therefore, we investigated the molecular basis of adventitious rooting in Populus and the model plant Arabidopsis. The production of adventitious roots (ARs) in tree cuttings is initiated from the basal stem region, and involves the interplay of several endogenous and exogenous factors. The roles of several hormones in this process have been characterized, but the effects of GAs have not been fully investigated. Here, we show that a GA treatment negatively affects the numbers of ARs produced by wild-type hybrid aspen cuttings. Furthermore, both hybrid aspen plants and intact Arabidopsis seedlings overexpressing AtGA20ox1, PttGID1.1 or PttGID1.3 genes (with a 35S promoter) produce few ARs, although ARs develop from the basal stem region of hybrid aspen and the hypocotyl of Arabidopsis. In Arabidopsis, auxin and strigolactones are known to affect AR formation. Our data show that the inhibitory effect of GA treatment on adventitious rooting is not mediated by perturbation of the auxin signalling pathway, or of the strigolactone biosynthetic and signalling pathways. Instead, GAs appear to act by perturbing polar auxin transport, in particular auxin efflux in hybrid aspen, and both efflux and influx in Arabidopsis.

  18. The Development Process of Adventitious Root of the Tea Shoots by Air Layering%茶树枝梢空中压条后不定根发育过程的初步研究

    Institute of Scientific and Technical Information of China (English)

    李丰; 张丽霞; 王乃栋; 刘洋

    2011-01-01

    为了探讨空中压条繁殖技术在茶树上应用的可行性,试验对环割、暗化及激素处理的黄绿色茶枝茎段外观形态和解剖结构进行观测,结果表明:(1)利用空中压条技术能使茶树茎段在母体上完成不定根诱导,并在环割口上端增粗的茎段上发出不定根,其所发根数及根的粗度均优于传统短穗扦插; (2)茶枝原始茎段无潜伏根原基,其茎段的不定根由诱生根原基发育而成; (3)在根原基发生过程中,还伴随着环割口愈伤组织形成及伤口上端茎段增粗的变化,愈伤形成小、茎粗增大显著的茎段易发生不定根.%In order to explore the feasibility of applying the air layering method for tea vegetative propagation, the yellowish-green stems were girdled, hormone treated and bound up, and then their changes of external morphology and the anatomical structure were observed and determined. The results showed that: (1) The adventitious roots could be induced and then grown out from the thicker stems above the wound of girdling before these stems were cut off, and these adventitious roots were more abundance and sturdy than those by the method of traditional cutting. (2) All the adventitious roots developed from induced primordial root because the primitive stem had no potential primordial root. (3) The callus inducted at the wound of girdling and the stem above the wound became thicker. It also showed that the stem with smaller callus tissue and thicker was easier to formed the adventitious root.

  19. Large Scale Culture of Ginseng Adventitious Roots for Production of Ginsenosides

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    Paek, Kee-Yoeup; Murthy, Hosakatte Niranjana; Hahn, Eun-Joo; Zhong, Jian-Jiang

    Ginseng (Panax ginseng C. A. Meyer) is one of the most famous oriental medicinal plants used as crude drugs in Asian countries, and now it is being used worldwide for preventive and therapeutic purposes. Among diverse constituents of ginseng, saponins (ginsenosides) have been found to be major components responsible for their biological and pharmacological actions. On the other hand, difficulties in the supply of pure ginsenosides in quantity prevent the development of ginseng for clinical medicines. Cultivation of ginseng in fields takes a long time, generally 5-7 years, and needs extensive effort regarding quality control since growth is susceptible to many environmental factors including soil, shade, climate, pathogens and pests. To solve the problems, cell and tissue cultures have been widely explored for more rapid and efficient production of ginseng biomass and ginsenosides. Recently, cell and adventitious root cultures of P. ginseng have been established in large scale bioreactors with a view to commercial application. Various physiological and engineering parameters affecting the biomass production and ginsenoside accumulation have been investigated. Advances in adventitious root cultures including factors for process scale-up are reviewed in this chapter. In addition, biosafety analyses of ginseng adventitious roots are also discussed for real application.

  20. Gravitropic response of adventitious roots cultivated in light and darkness on sucrose-free medium.

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    Vinterhalter, D V; Vinterhalter, B S

    1999-11-30

    Elongation of adventitious roots of Dracaena fragrans was investigated under photoautotrophic conditions. Root elongation decreased and stopped when cultures were transferred to darkness. Upon return to light roots renewed growth after a 5 day lag period. During the first two days of intensive new growth roots were agravitropic elongating in random directions. Investigation showed that transient absence of geotropic response was connected with disappearance of starch grains in root tip which occurred due to sucrose starvation of cultures in continuous darkness.

  1. A co-opted hormonal cascade activates dormant adventitious root primordia upon flooding in solanum dulcamara

    NARCIS (Netherlands)

    Dawood, Thikra; Yang, Xinping; Visser, Eric J.W.; Beek, Te Tim A.H.; Kensche, Philip R.; Cristescu, Simona M.; Lee, Sangseok; Floková, Kristýna; Nguyen, Duy; Mariani, Celestina; Rieu, Ivo

    2016-01-01

    Soil flooding is a common stress factor affecting plants. To sustain root function in the hypoxic environment, flooding-tolerant plants may form new, aerenchymatous adventitious roots (ARs), originating from preformed, dormant primordia on the stem. We investigated the signaling pathway behind AR

  2. Aquatic adventitious roots of the wetland plant Meionectes brownii can photosynthesize

    DEFF Research Database (Denmark)

    Rich, Sarah Meghan; Ludwig, Martha; Pedersen, Ole

    2011-01-01

    • Many wetland plants produce aquatic adventitious roots from submerged stems. Aquatic roots can form chloroplasts, potentially producing endogenous carbon and oxygen. Here, aquatic root photosynthesis was evaluated in the wetland plant Meionectes brownii, which grows extensive stem-borne aquatic...... m(-3) dissolved CO(2), aquatic roots fix carbon at 0.016 µmol CO(2) g(-1) DM s(-1). Illuminated aquatic roots do not rely on exogenous inputs of O(2). • The photosynthetic ability of aquatic roots presumably offers an advantage to submerged M. brownii as aquatic roots, unlike sediment roots, need...

  3. Early steps of adventitious rooting: morphology, hormonal profiling and carbohydrate turnover in carnation stem cuttings.

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    Agulló-Antón, María Ángeles; Ferrández-Ayela, Almudena; Fernández-García, Nieves; Nicolás, Carlos; Albacete, Alfonso; Pérez-Alfocea, Francisco; Sánchez-Bravo, José; Pérez-Pérez, José Manuel; Acosta, Manuel

    2014-03-01

    The rooting of stem cuttings is a common vegetative propagation practice in many ornamental species. A detailed analysis of the morphological changes occurring in the basal region of cultivated carnation cuttings during the early stages of adventitious rooting was carried out and the physiological modifications induced by exogenous auxin application were studied. To this end, the endogenous concentrations of five major classes of plant hormones [auxin, cytokinin (CK), abscisic acid, salicylic acid (SA) and jasmonic acid] and the ethylene precursor 1-aminocyclopropane-1-carboxylic acid were analyzed at the base of stem cuttings and at different stages of adventitious root formation. We found that the stimulus triggering the initiation of adventitious root formation occurred during the first hours after their excision from the donor plant, due to the breakdown of the vascular continuum that induces auxin accumulation near the wounding. Although this stimulus was independent of exogenously applied auxin, it was observed that the auxin treatment accelerated cell division in the cambium and increased the sucrolytic activities at the base of the stem, both of which contributed to the establishment of the new root primordia at the stem base. Further, several genes involved in auxin transport were upregulated in the stem base either with or without auxin application, while endogenous CK and SA concentrations were specially affected by exogenous auxin application. Taken together our results indicate significant crosstalk between auxin levels, stress hormone homeostasis and sugar availability in the base of the stem cuttings in carnation during the initial steps of adventitious rooting.

  4. Low temperature, IBA concentrations and optimal time for adventitious rooting of Eucalyptus benthamii mini-cuttings

    Institute of Scientific and Technical Information of China (English)

    Gilvano Ebling Brondani; Francisco José Benedini Baccarin; Heron Wilhelmus de Wit Ondas; José Luiz Stape; Antonio Natal Gon(c)alves; Marcilio de Almeida

    2012-01-01

    Eucalyptus benthamii is a forest species of economic interest that has difficulty with seed production and also is considered to have difficulty with adventitious rooting using propagation techniques,such as cutting or mini-cutting.We aimed to assess the adventitious rooting percentage under different storage times in low temperatures and at various IBA (indole-3-butyric acid) concentrations to determine the optimal time of permanence for rooting Eucalyptus benthamii minicuttings in a greenhouse.Shoots collected from mini-stumps cultivated in a semi-hydroponic system were used to obtain the mini-cuttings.For the first experiment,the mini-cuttings were stored at 4℃ for 0 (immediate planting),24,48,72,96 and 120 h.The second experiment evaluated the rooting dynamic to determine the optimal time of permanence for minicuttings in a greenhouse.The basal region of the mini-cutting was treated with various 1BA solutions:0 (free of IBA),1,000,2,000,3,000 and 4,000 mg·L-1.Every seven days (0 (immediate planting),7,14,21 and 28days),destructive sampling of the mini-cuttings was performed to evaluate the histology of the adventitious rooting.Eucalyptus benthamii minicuttings should be rooted immediately after the collection of the shoots.The 2,000 mg·L-1 IBA concentration induced a greater speed and percentage of adventitious rooting,and an interval of 35 to 42 days was indicated for permanence of the mini-cuttings in the greenhouse.Exposure to low temperature induced adventitious root formation with diffuse vascular connections.

  5. An Efficient Method for Adventitious Root Induction from Stem Segments of Brassica Species.

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    Srikanth, Sandhya; Choong, Tsui Wei; Yan, An; He, Jie; Chen, Zhong

    2016-01-01

    Plant propagation via in vitro culture is a very laborious and time-consuming process. The growth cycle of some of the crop species is slow even in the field and the consistent commercial production is hard to maintain. Enhanced methods of reduced cost, materials and labor significantly impact the research and commercial production of field crops. In our studies, stem-segment explants of Brassica species were found to generate adventitious roots (AR) in aeroponic systems in less than a week. As such, the efficiency of rooting from stem explants of six cultivar varieties of Brassica spp was tested without using any plant hormones. New roots and shoots were developed from Brassica alboglabra (Kai Lan), B. oleracea var. acephala (purple kale), B. rapa L. ssp. chinensis L (Pai Tsai, Nai Bai C, and Nai Bai T) explants after 3 to 5 days of growing under 20 ± 2°C cool root zone temperature (C-RZT) and 4 to 7 days in 30 ± 2°C ambient root zone temperature (A-RZT). At the base of cut end, anticlinal and periclinal divisions of the cambial cells resulted in secondary xylem toward pith and secondary phloem toward cortex. The continuing mitotic activity of phloem parenchyma cells led to a ring of conspicuous white callus. Root initials formed from the callus which in turn developed into ARs. However, B. rapa var. nipposinica (Mizuna) explants were only able to root in C-RZT. All rooted explants were able to develop into whole plants, with higher biomass obtained from plants that grown in C-RZT. Moreover, explants from both RZTs produced higher biomass than plants grown from seeds (control plants). Rooting efficiency was affected by RZTs and explant cuttings of donor plants. Photosynthetic CO2 assimilation rate (Asat ) and stomatal conductance (gssat ) were significantly differentiated between plants derived from seeds and explants at both RZTs. All plants in A-RZT had highest transpiration rates.

  6. Pilot-scale culture of Hypericum perforatum L. adventitious roots in airlift bioreactors for the production of bioactive compounds.

    Science.gov (United States)

    Cui, Xi-Hua; Murthy, Hosakatte Niranjana; Paek, Kee-Yoeup

    2014-09-01

    Hypericum perforatum L. (St. John's Wort) is an important medicinal plant which is widely used in the treatment for depression and irritable bowel syndrome. It is also used as a dietary supplement. Major bioactive phytochemicals of H. perforatum are phenolics and flavonoids. Quality of these phytochemicals is dramatically influenced by environmental and biological factors in the field grown plants. As an alternative, we have developed adventitious root cultures in large-scale bioreactors for the production of useful phytochemicals. Adventitious roots of H. perforatum were cultured in 500 l pilot-scale airlift bioreactors using half-strength Murashige and Skoog medium with an ammonium and nitrate ratio of 5:25 mM and supplemented with 1.0 mg l(-1) indole butyric acid, 0.1 mg l(-1) kinetin, and 3 % sucrose for the production of bioactive phenolics and flavonoids. Then 4.6 and 6.3 kg dry biomass were realized in the 500 l each of drum-type and balloon-type bioreactors, respectively. Accumulation of 66.9 mg g(-1) DW of total phenolics, 48.6 mg g(-1) DW of total flavonoids, 1.3 mg g(-1) DW of chlorogenic acid, 0.01 mg g(-1) DW of hyperin, 0.04 mg g(-1) DW of hypericin, and 0.01 mg g(-1) DW of quercetin could be achieved with adventitious roots cultured in 500 l balloon-type airlift bioreactors. Our findings demonstrate the possibilities of using H. perforatum adventitious root cultures for the production of useful phytochemicals to meet the demand of pharmaceutical and food industry.

  7. Identification of pectin methylesterase 3 as a basic pectin methylesterase isoform involved in adventitious rooting in Arabidopsis thaliana.

    Science.gov (United States)

    Guénin, Stéphanie; Mareck, Alain; Rayon, Catherine; Lamour, Romain; Assoumou Ndong, Yves; Domon, Jean-Marc; Sénéchal, Fabien; Fournet, Françoise; Jamet, Elisabeth; Canut, Hervé; Percoco, Giuseppe; Mouille, Grégory; Rolland, Aurélia; Rustérucci, Christine; Guerineau, François; Van Wuytswinkel, Olivier; Gillet, Françoise; Driouich, Azeddine; Lerouge, Patrice; Gutierrez, Laurent; Pelloux, Jérôme

    2011-10-01

    • Here, we focused on the biochemical characterization of the Arabidopsis thaliana pectin methylesterase 3 gene (AtPME3; At3g14310) and its role in plant development. • A combination of biochemical, gene expression, Fourier transform-infrared (FT-IR) microspectroscopy and reverse genetics approaches were used. • We showed that AtPME3 is ubiquitously expressed in A. thaliana, particularly in vascular tissues. In cell wall-enriched fractions, only the mature part of the protein was identified, suggesting that it is processed before targeting the cell wall. In all the organs tested, PME activity was reduced in the atpme3-1 mutant compared with the wild type. This was related to the disappearance of an activity band corresponding to a pI of 9.6 revealed by a zymogram. Analysis of the cell wall composition showed that the degree of methylesterification (DM) of galacturonic acids was affected in the atpme3-1 mutant. A change in the number of adventitious roots was found in the mutant, which correlated with the expression of the gene in adventitious root primordia. • Our results enable the characterization of AtPME3 as a major basic PME isoform in A. thaliana and highlight its role in adventitious rooting.

  8. Development and growth of plantlets of Pinus contorta regenerated from adventitious buds

    Energy Technology Data Exchange (ETDEWEB)

    Flygh, G.; Groenroos, R.; Arnold, S. von [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Genetics; Hoegberg, K.A. [The Association for Forest Tree Breeding, Svaloev (Sweden)

    1998-11-01

    Before micropropagation techniques can be applied to a particular species, it is crucial to optimize the method and to determine how the micropropagated plants grow in the field. Adventitious shoots developed on embryos of Pinus contorta Dougl. ex Loud. after a 2 h pulse treatment with 250 {mu}M N6-benzyladenine. The time to first subculture after the pulse treatment influenced the yield of adventitious shoots. On average, 68% of the adventitious shoots had developed roots 12 weeks after treatment with 1.25 mM indole-3-butyric acid for 6 h. The auxin treatment stimulated early rooting (i.e. within 6 weeks) but had no effect on late rooting (i.e. after 6 weeks). The size of the plantlets was of importance for the survival when potted. All plantlets with a distinct stem elongated during the first growth period while some without did not. The relative height growth rate of plantlets was similar to that of seedlings. In the field the increase of height was similar for plantlets and seedlings. Plagiotropy was higher for the plantlets than for the seedlings (35 and 10% respectively). We concluded that most plantlets of P. contorta elongate normally and have a similar gross morphology to seedlings 23 refs, 8 figs, 4 tabs

  9. Gonadotropin promotion of adventitious root production on cuttings of Begonia semperflorens and Vitis vinifera.

    Science.gov (United States)

    Leshem, Y; Lunenfeld, B

    1968-03-01

    Adventitious rooting of Begonia semperflorens cv. Indian Maid and Vitis vinifera cv. Semillon stem cuttings was significantly promoted by human chorionic gonadotropin (HCG). Basal sections of HCG treated cuttings upon which promoted rooting took place had markedly less endogenous gibberellin (GA) activity than non-treated controls or apical sections of treated ones, while changes in auxin levels were not found. HCG also inhibited GA(3)-induced reducing sugar release from embryoless barley endosperm halves. These findings are discussed in the light of a possible analogy to gonadotropin action in animal systems.

  10. Gonadotropin Promotion of Adventitious Root Production on Cuttings of Begonia semperflorens and Vitis vinifera 1

    Science.gov (United States)

    Leshem, Y.; Lunenfeld, B.

    1968-01-01

    Adventitious rooting of Begonia semperflorens cv. Indian Maid and Vitis vinifera cv. Semillon stem cuttings was significantly promoted by human chorionic gonadotropin (HCG). Basal sections of HCG treated cuttings upon which promoted rooting took place had markedly less endogenous gibberellin (GA) activity than non-treated controls or apical sections of treated ones, while changes in auxin levels were not found. HCG also inhibited GA3-induced reducing sugar release from embryoless barley endosperm halves. These findings are discussed in the light of a possible analogy to gonadotropin action in animal systems. PMID:5641189

  11. Growth and Anatomical Parameters of Adventitious Roots Formed on Mung Bean Hypocotyls Are Correlated with Galactoglucomannan Oligosaccharides Structure

    Directory of Open Access Journals (Sweden)

    K. Kollárová

    2012-01-01

    Full Text Available The effect of galactoglucomannan oligosaccharides (GGMOs compared with chemically modified oligosaccharides, GGMOs-g (with reduced number of D-galactose side chains and GGMOs-r (with reduced reducing ends on mung bean (Vigna radiata (L. Wilczek adventitious roots formation, elongation, and anatomical structure have been studied. All types of oligosaccharides influenced adventitious root formation in the same way: stimulation in the absence of exogenous auxin and inhibition in the presence of exogenous auxin. Both reactions are probably related with the presence/content of endogenous auxin in plant cuttings. However, the adventitious root length was inhibited by GGMOs both in the absence as well as in the presence of auxin (IBA or NAA, while GGMOs-g inhibition was significantly weaker compared with GGMOs. GGMOs-r were without significant difference on both processes, compared with GGMOs. GGMOs affected not only the adventitious root length but also their anatomy in dependence on the combination with certain type of auxin. The oligosaccharides influenced cortical cells division, which was reflected in the cortex area and in the root diameter. All processes followed were dependent on oligosaccharides chemical structure. The results suggest also that GGM-derived oligosaccharides may play an important role in adventitious roots elongation but not in their formation.

  12. Improvement of Growth and Periplocin Yield of Periploca sepium Adventitious Root Cultures by Altering Nitrogen Source Supply

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jian; GAO Wen-yuan; WANG Juan; LI Xing-lin; XIAO Pei-gen

    2011-01-01

    Objective To increase the ultimate yield of periplocin in Periploca sepium adventitious root cultures by a two-stage culture based on nitrogen source.Methods Firstly,the effects of nitrogen source(NH-NO-)at different ratios and different total initial nitrogen amounts on the accumulation of biomass and secondary metabolites in adventitious root cultures of P sepium were investigated,and growth and production media for the two-stage culture based on the above results were established.Results The highest biomass and periplocin content were obtained in the culture medium of 15 mmol/L total nitrogen amount with NH-NO(1:2)and 30 mmol/L total nitrogen amount with nitrate as the sole nitrogen source.By adopting a fed-batch cultivation strategy,the dry weight adventitious root,periplocin content and yield were increased by 136%,108%,and 389%,respectively when compared with those of the control,reaching up to 8.13 g/L,157.15 μg/g,and 1277.63 μg/L,respectively.Furthermore,it was found that in the process of two-stage culture,the adventitious roots grew thicker significantly after they were transferred into production medium directly.Conclusion The ultimate yield of periplocin in P.sepium adventitious root cultures could be significantly increased by a two-stage culture based on nitrogen source.

  13. Triterpene and Flavonoid Biosynthesis and Metabolic Profiling of Hairy Roots, Adventitious Roots, and Seedling Roots of Astragalus membranaceus.

    Science.gov (United States)

    Park, Yun Ji; Thwe, Aye Aye; Li, Xiaohua; Kim, Yeon Jeong; Kim, Jae Kwang; Arasu, Mariadhas Valan; Al-Dhabi, Naif Abdullah; Park, Sang Un

    2015-10-14

    Astragalus membranaceus is an important traditional Chinese herb with various medical applications. Astragalosides (ASTs), calycosin, and calycosin-7-O-β-d-glucoside (CG) are the primary metabolic components in A. membranaceus roots. The dried roots of A. membranaceus have various medicinal properties. The present study aimed to investigate the expression levels of genes related to the biosynthetic pathways of ASTs, calycosin, and CG to investigate the differences between seedling roots (SRs), adventitious roots (ARs), and hairy roots (HRs) using quantitative real-time polymerase chain reaction (qRT-PCR). qRT-PCR study revealed that the transcription level of genes involved in the AST biosynthetic pathway was lowest in ARs and showed similar patterns in HRs and SRs. Moreover, most genes involved in the synthesis of calycosin and CG exhibited the highest expression levels in SRs. High-performance liquid chromatography (HPLC) analysis indicated that the expression level of the genes correlated with the content of ASTs, calycosin, and CG in the three different types of roots. ASTs were the most abundant in SRs. CG accumulation was greater than calycosin accumulation in ARs and HRs, whereas the opposite was true in SRs. Additionally, 40 metabolites were identified using gas chromatography-time-of-flight mass spectrometry (GC-TOF-MS). Principal component analysis (PCA) documented the differences among SRs, ARs, and HRs. PCA comparatively differentiated among the three samples. The results of PCA showed that HRs were distinct from ARs and SRs on the basis of the dominant amounts of sugars and clusters derived from closely similar biochemical pathways. Also, ARs had a higher concentration of phenylalanine, a precursor for the phenylpropanoid biosynthetic pathway, as well as CG. TCA cycle intermediates levels including succinic acid and citric acid indicated a higher amount in SRs than in the others.

  14. The effects of pruning and nodal adventitious roots on polychlorinated biphenyl uptake by Cucurbita pepo grown in field conditions

    Energy Technology Data Exchange (ETDEWEB)

    Low, Jennifer E.; Whitfield Aslund, Melissa L. [Department of Chemistry and Chemical Engineering, Royal Military College of Canada, PO Box 17000 Station Forces, Kingston, ON, K7K 7B4 (Canada); Rutter, Allison [School of Environmental Studies, Rm 0626 Biosciences Complex, Queen' s University, 116 Barrie St., Kingston, ON, K7L 3N6 (Canada); Zeeb, Barbara A., E-mail: zeeb-b@rmc.ca [Department of Chemistry and Chemical Engineering, Royal Military College of Canada, PO Box 17000 Station Forces, Kingston, ON, K7K 7B4 (Canada)

    2011-03-15

    Two cultivation techniques (i-pruning and ii-nodal adventitious root encouragement) were investigated for their ability to increase PCB phytoextraction by Cucurbita pepo ssp pepo cv. Howden (pumpkin) plants in situ at a contaminated industrial site in Ontario (Aroclor 1248, mean soil [PCB] = 5.6 {mu}g g{sup -1}). Pruning was implemented to increase plant biomass close to the root where PCB concentration is known to be highest. This treatment was found to have no effect on final shoot biomass or PCB concentration. However, material pruned from the plant is not included in the final shoot biomass. The encouragement of nodal adventitious roots at stem nodes did significantly increase the PCB concentration in the primary stem, while not affecting shoot biomass. Both techniques are easily applied cultivation practices that may be implemented to decrease phytoextraction treatment time. - Research highlights: > Presence of nodal adventitious roots do increase phytoextraction efficiency. > Pruning may increase the biomass of pumpkin plants during phytoextraction. > [Aroclor 1248] decreases in plant tissue with increasing distance from the root. - The application of cultivation practices (pruning and nodal adventitious root encouragement) increases phytoextraction of PCBs in C. pepo.

  15. NO和NADPH-黄递酶在绿豆下胚轴不定根发生和发育过程中的变化%Change of Nitric Oxide and NADPH-diaphorase During the Generation and the Development of Adventitious Roots in Mung Bean Hypocotyl Cuttings

    Institute of Scientific and Technical Information of China (English)

    佘小平; 黄爱霞

    2004-01-01

    Effects of nitric oxide (NO) donor sodium nitroprusside (SNP), NO specific scavenger c-PTIO and nitric oxide synthase (NOS) inhibitor L-NAME on the rooting of mung bean ( Vigna radiata L.) hypocotyl cuttings were studied. The spatio-temporal changes of NO and NADPH-diaphorase in the basal part of cutting were also detected during the adventitious rooting process. The results showed that SNP significantly enhanced the adventitious rooting in the range of concentrations tested. NADPH-diaphorase activity (commonly employed as a marker for NOS) and the fluorescence of NO were respectively observed in the zone between the vascular bundles of the basal part of cuttings at 24 h and 36 h after cutting. The root primordium became discernible at 48 h after cutting in the same region, and became more elongate at 60 h. NADPH-diaphorase activity and NO fluorescence gradually increased during 48-60 h and mainly distributed in root meristem. L-NAME treatment delayed adventitious root emergency and significantly reduced the NADPH-diaphorase staining and the fluorescence of NO. The specific NO scavenger, c-PTIO,also suppressed the fluorescence and inhibited the formation of adventitious roots. These results suggest that endogenous NO appears to play a key role in the generation and development of adventitious roots,and the production of NO in this process may be catalyzed by NOS-like enzyme.%研究了一氧化氮(NO)供体普钠(SNP)、一氧化氮清除剂C-PTIO和一氧化氮合酶(NOS)抑制L-NAME对绿豆(Vigna radiataL.)下胚轴插条生根的影响.并对不定根生期间手条基部NO\t和NADPH-黄递酶的时空变化进行了检测.所试浓度SNP均明显促进下胚轴不根发生.分别插条切取后24h和36h于其基部维管束之间检测到NADPH-黄递酶(NOS标记酶)阳性反应和NO荧光,根原基也于48h在相同位置出现,并于60h进一步伸长.48~60h期间,NADPH、黄递的阳性反应及NO荧光有增强趋势,并主要分布在不定根分生组织

  16. Hypoperfusion of the Adventitial Vasa Vasorum Develops an Abdominal Aortic Aneurysm.

    Science.gov (United States)

    Tanaka, Hiroki; Zaima, Nobuhiro; Sasaki, Takeshi; Sano, Masaki; Yamamoto, Naoto; Saito, Takaaki; Inuzuka, Kazunori; Hayasaka, Takahiro; Goto-Inoue, Naoko; Sugiura, Yuki; Sato, Kohji; Kugo, Hirona; Moriyama, Tatsuya; Konno, Hiroyuki; Setou, Mitsutoshi; Unno, Naoki

    2015-01-01

    The aortic wall is perfused by the adventitial vasa vasorum (VV). Tissue hypoxia has previously been observed as a manifestation of enlarged abdominal aortic aneurysms (AAAs). We sought to determine whether hypoperfusion of the adventitial VV could develop AAAs. We created a novel animal model of adventitial VV hypoperfusion with a combination of a polyurethane catheter insertion and a suture ligation of the infrarenal abdominal aorta in rats. VV hypoperfusion caused tissue hypoxia and developed infrarenal AAA, which had similar morphological and pathological characteristics to human AAA. In human AAA tissue, the adventitial VV were stenotic in both small AAAs (30-49 mm in diameter) and in large AAAs (> 50 mm in diameter), with the sac tissue in these AAAs being ischemic and hypoxic. These results indicate that hypoperfusion of adventitial VV has critical effects on the development of infrarenal AAA.

  17. Adventitious root formation in rice requires OsGNOM1 and is mediated by the OsPINs family

    Institute of Scientific and Technical Information of China (English)

    Shiping Liu; Jirong Wang; Lu Wang; Xiaofei Wang; Yanhong Xue; Ping Wu; Huixia Shou

    2009-01-01

    The fibrous root system in cereals comprises primarily adventitious roots (ARs), which play important roles in nu-trient and water uptake. Current knowledge regarding the molecular mechanism underlying AR development is still limited. We report here the isolation of four rice (Oryza sativa L.) mutants, from different genetic backgrounds, all of which were defective in AR formation. These mutants exhibited reduced numbers of lateral roots (LRs) and partial loss of gravitropism. The mutants also displayed enhanced sensitivity to N-1-napbthylphthalamic acid, an inhibitor of polar auxin transport (PAT), indicating that the mutations affected auxin transport. Positional cloning using one of the four mutants revealed that it was caused by loss-of-function of a guanine nucleotide exchange factor for ADP-ribosylation factor (OsGNOM1). RT-PCR and analysis of promoter::GUS transgenic plants showed that OsGNOM1 is expressed in AR primordia, vascular tissues, LRs, root tips, leaves, anthers and lemma veins, with a distribution pattern similar to that of auxin. In addition, the expressions of OsPIN2, OsPINSb and OsPIN9 were altered in the mu-tants. Taken together, these findings indicate that OsGNOM1 affects the formation of ARs through regulating PAT.

  18. Introductory studies of bacterial effects on the course of mitosis in adventitious roots of Allium cepa L.

    Directory of Open Access Journals (Sweden)

    J. Cebrat

    2015-01-01

    Full Text Available The level of spontaneous chromosome aberrations and other phenomena concomitant with mitoses in the meristematic cells of Allium cepa L. adventitious roots grown in water, depends to a large extent on the intensity of bacteria multiplication. From the water culture two strains of bacteria, which were most numerous, were isolated - Agrobacterium and Flavobacterium. A supernatant from bacteria grown on Davis medium induced chromosome sticking together, c-mitoses and the formation of polyploid nuclei in the roots of onion.

  19. Inheritance and quantitative trail loci mapping of adventitious root numbers in cucumber seedlings under waterlogging conditions.

    Science.gov (United States)

    Xu, Xuewen; Ji, Jing; Xu, Qiang; Qi, Xiaohua; Chen, Xuehao

    2017-04-01

    The hypocotyl-derived adventitious root (AR) is an important morphological acclimation to waterlogging stress; however, its genetic basis has not been adequately understood. In the present study, a mixed major gene plus polygene inheritance model was used to analyze AR numbers (ARN) 7 days after waterlogging treatment in six generations (P1, P2, F1, B1, B2, and F2), using cucumber waterlogging tolerant line Zaoer-N and sensitive Pepino as parents. The results showed that the genetic model D-4, mixed one negative dominance major gene and additive-dominance polygenes, is the best-fitting genetic model for waterlogging-triggered ARN phenotype. A genetic linkage map spanning 550.8 cM and consisting of 149 simple sequence repeat (SSR) markers segregating into seven linkage groups was constructed. Three QTLs (ARN3.1, ARN5.1, and ARN6.1) distributed on chromosomes 3, 5, and 6 were identified by composite interval mapping. The major-effect QTL, ARN6.1, located between SSR12898 and SSR04751, was the only locus detected in three seasons, with least likelihood (LOD) scores of 8.8, 10.4, and 9.5 and account for 17.6, 24, and 19.8% of the phenotypic variance, respectively. Using five additional single nucleotide polymorphism (SNP) makers, the ARN6.1 was narrowed down to a 0.79 Mb interval franked by SSR12898 and SNP25558853. Illumina RNA-sequencing data generated on hypocotyls of two parents 48 h after waterlogging treatment revealed 15 genes in the 0.79 Mb interval were differentially expressed, including Csa6G503880 encoding a salicylic acid methyl transferase-like protein, Csa6G504590 encoding a cytochrome P450 monooxygenase, and Csa6G505230 encoding a heavy metal-associated protein. Our findings shed light on the genetic architecture underlying adventitious rooting during waterlogging stress in cucumber, and provide a list of potential gene targets for further elucidating waterlogging tolerance in plants.

  20. On the effects of secretions of saprophytic bacteria on the course of mitosis in adventitious roots of Allium cepa L.

    OpenAIRE

    Z. Kobierzyńska

    2015-01-01

    The influence of 21 strains of saprophytic bacteria isolated from onion cultures on the course of mitosis and on the level of chromosome aberrations in adventitious roots of Allium cepa L. was studied. Liquid cultures of all bacterial strains caused no changes in divisions of the cells. However, ten of the strains were responsible for disturbances in this process. The nature of these disturbances depended to a large extent on the kind of medium in which the bacteria were grown.

  1. On the effects of secretions of saprophytic bacteria on the course of mitosis in adventitious roots of Allium cepa L.

    Directory of Open Access Journals (Sweden)

    Z. Kobierzyńska

    2015-01-01

    Full Text Available The influence of 21 strains of saprophytic bacteria isolated from onion cultures on the course of mitosis and on the level of chromosome aberrations in adventitious roots of Allium cepa L. was studied. Liquid cultures of all bacterial strains caused no changes in divisions of the cells. However, ten of the strains were responsible for disturbances in this process. The nature of these disturbances depended to a large extent on the kind of medium in which the bacteria were grown.

  2. De novo adventitious root formations in mini-cuttings of Azadirachta indica in response to different rooting media and auxin treatments

    Directory of Open Access Journals (Sweden)

    Gehlot A

    2015-08-01

    Full Text Available Neem (Azadirachta indica A. Juss is a multipurpose Indian tree important to local economy. Conservation of the genetic resources of neem is essential for the adaptability of this tree species to projected climate change impacts. Here, the effect of type and concentration of auxins in different rooting media on adventitious root formation (ARF in mini-cuttings of Azadirachta indica is depicted. Three different rooting media (i.e., sand, vermiculite and soil were used, and the experiment was established using three types of auxin (IBA, IAA and NAA and 6 concentration treatment combinations (100, 250, 500, 750, 1000 and 1500 mg l-1, in a complete randomized block design (CRBD. Significant effects of different auxin types, concentration treatments and rooting media on adventitious root formation of neem mini-cuttings were observed. Mini-cuttings were assessed for rooting percentage, number of roots, root length and number of leaves. IBA resulted in higher rooting percentage (90%, number of roots (149.56, root length (14.83 cm and number of leaves per rooted mini-cuttings (12.78, when growing in sand. The determination of proper rooting protocols and the use of mini-cuttings were proved important for improving mass propagation of A. indica.

  3. Plant hormone homeostasis, signaling and function during adventitious root formation in cuttings

    Directory of Open Access Journals (Sweden)

    Uwe eDruege

    2016-03-01

    Full Text Available Adventitious root (AR formation in cuttings is a multiphase developmental process, resulting from wounding at the cutting site and isolation from the resource and signal network of the whole plant. Though promotive effects of auxins are widely used for clonal plant propagation, the regulation and function of plant hormones and their intricate signaling networks during AR formation in cuttings are poorly understood. In this focused review, we discuss our recent publications on the involvement of polar auxin transport (PAT and transcriptional regulation of auxin and ethylene action during AR formation in petunia cuttings in a broad context. Integrating new findings on cuttings of other plant species and general models on plant hormone networks, a model on the regulation and function of auxin, ethylene and jasmonate in AR formation of cuttings is presented. PAT and cutting off from the basipetal auxin drain are considered as initial principles generating early accumulation of IAA in the rooting zone. This is expected to trigger a self-regulatory process of auxin canalization and maximization to responding target cells, there inducing the program of AR formation. Regulation of auxin homeostasis via auxin influx and efflux carriers, GH3 proteins and peroxidases, of flavonoid metabolism and of auxin signaling via AUX/IAA proteins, TOPLESS, ARFs and SAUR-like proteins are postulated as key processes determining the different phases of AR formation. NO and H2O2 mediate auxin signaling via the cGMP and MAPK cascades. Transcription factors of the GRAS-, AP2/ERF- and WOX-families link auxin signaling to cell fate specification. Cyclin-mediated governing of the cell cycle, modifications of sugar metabolism and microtubule and cell wall remodeling are considered as important implementation processes of auxin function. Induced by the initial wounding and other abiotic stress factors, up-regulation of ethylene biosynthesis and signaling via ERFs and early

  4. Generation of hermaphrodite transgenic papaya lines with virus resistance via transformation of somatic embryos derived from adventitious roots of in vitro shoots.

    Science.gov (United States)

    Kung, Yi-Jung; Yu, Tsong-Ann; Huang, Chiung-Huei; Wang, Hui-Chin; Wang, Shin-Lan; Yeh, Shyi-Dong

    2010-08-01

    Papaya production is seriously limited by Papaya ringspot virus (PRSV) worldwide and Papaya leaf-distortion mosaic virus (PLDMV) in Eastern Asia. An efficient transformation method for developing papaya lines with transgenic resistance to these viruses and commercially desirable traits, such as hermaphroditism, is crucial to shorten the breeding program for this fruit crop. In this investigation, an untranslatable chimeric construct pYP08 containing truncated PRSV coat protein (CP) and PLDMV CP genes coupled with the 3' untranslational region of PLDMV, was generated. Root segments from different portions of adventitious roots of in vitro multiple shoots of hermaphroditic plants of papaya cultivars 'Tainung No. 2', 'Sunrise', and 'Thailand' were cultured on induction medium for regeneration into somatic embryos. The highest frequency of somatic embryogenesis was from the root-tip segments of adventitious roots developed 2-4 weeks after rooting in perlite medium. After proliferation, embryogenic tissues derived from somatic embryos were wounded in liquid-phase by carborundum and transformed by Agrobacterium carrying pYP08. Similarly, another construct pBG-PLDMVstop containing untranslatable CP gene of PLDMV was also transferred to 'Sunrise' and 'Thailand', the parental cultivars of 'Tainung No. 2'. Among 107 transgenic lines regenerated from 349 root-tip segments, nine lines of Tainung No. 2 carrying YP08 were highly resistant to PRSV and PLDMV, and 9 lines (8 'Sunrise' and 1 'Thailand') carrying PLDMV CP highly resistant to PLDMV, by a mechanism of post-transcriptional gene silencing. The hermaphroditic characteristics of the transgenic lines were confirmed by PCR with sex-linked primers and phenotypes of flower and fruit. Our approach has generated transgenic resistance to both PRSV and PLDMV with commercially desirable characters and can significantly shorten the time-consuming breeding programs for the generation of elite cultivars of papaya hybrids.

  5. Liquid Culture of Adventitious Roots is a Potential Alternative to Field Cultivation for Psammosilene tunicoides, a Rare and Endangered Endemic Medicinal Plant

    Directory of Open Access Journals (Sweden)

    Zongshen Zhang

    2013-02-01

    Full Text Available The aim of this study was to establish an adventitious roots culture system for sterile plantlet segments of P. tunicoides and improved the accumulation of total saponins in cultured roots. Psammosilene tunicoides is a native Chinese plant with high commercial value as medicinal herb. Combination of NAA and IBA significantly affected the adventitious roots formation on agar-solided B5 media and a maximal induction rate of 83% was obtained at 24±2°C with a photoperiod of 12 h. With a shaking of 110 rpm in darkness, transferring the detached adventitious roots to the growth regulator free 1/2 B5 liquid media notably increased the biomass production compared to that on solid media over a 30-day-culture period. Further analyses showed that more saponins could be accumulated in the liquid culture than in the solid culture and the addition of exogenous oxalic acid to the liquid media could enhance the accumulation of total saponins in adventitious roots. These results suggested that adventitious roots culture will be an efficient alternative to the field cultivation of intact plants for the production of useful natural compounds from P. tunicoides.

  6. Reference gene selection for quantitative reverse transcription-polymerase chain reaction normalization during in vitro adventitious rooting in Eucalyptus globulus Labill

    Directory of Open Access Journals (Sweden)

    Pasquali Giancarlo

    2010-09-01

    Full Text Available Abstract Background Eucalyptus globulus and its hybrids are very important for the cellulose and paper industry mainly due to their low lignin content and frost resistance. However, rooting of cuttings of this species is recalcitrant and exogenous auxin application is often necessary for good root development. To date one of the most accurate methods available for gene expression analysis is quantitative reverse transcription-polymerase chain reaction (qPCR; however, reliable use of this technique requires reference genes for normalization. There is no single reference gene that can be regarded as universal for all experiments and biological materials. Thus, the identification of reliable reference genes must be done for every species and experimental approach. The present study aimed at identifying suitable control genes for normalization of gene expression associated with adventitious rooting in E. globulus microcuttings. Results By the use of two distinct algorithms, geNorm and NormFinder, we have assessed gene expression stability of eleven candidate reference genes in E. globulus: 18S, ACT2, EF2, EUC12, H2B, IDH, SAND, TIP41, TUA, UBI and 33380. The candidate reference genes were evaluated in microccuttings rooted in vitro, in presence or absence of auxin, along six time-points spanning the process of adventitious rooting. Overall, the stability profiles of these genes determined with each one of the algorithms were very similar. Slight differences were observed in the most stable pair of genes indicated by each program: IDH and SAND for geNorm, and H2B and TUA for NormFinder. Both programs indentified UBI and 18S as the most variable genes. To validate these results and select the most suitable reference genes, the expression profile of the ARGONAUTE1 gene was evaluated in relation to the most stable candidate genes indicated by each algorithm. Conclusion Our study showed that expression stability varied between putative reference genes

  7. Study on Factors Influencing Development of Adventitious Root Primordium of Tea after Air Layering%茶树空中压条不定根原基发育影响因子研究

    Institute of Scientific and Technical Information of China (English)

    李丰; 张丽霞

    2011-01-01

    为了筛选出促使茶树茎段空中压条后发根的最佳技术方案,研究了成熟度、外施激素浓度、枝梢茎粗以及环割方式对根原基发育的影响.结果表明:选择生长健壮、茎粗为0.252 ~0.280 cm的当年生枝条,在黄绿色或青绿色茎段处进行传统环割,外用100 mg/L的ABT 1号生根粉处理,能有效缩短根原基发育周期.经过40~50 d,当茎段表皮隆起或出现白色根点时,即可剪离母体继续进行基质根系培养.%In order to select the best technique for rooting of the girdled tea branches, the effects of maturation degree, exogenous hormones concentration, stem diameter and girdling mode on development of root primordhim were studied in this paper. The results showed that the healthy and strong branches should be chosen with 0. 25 ~0. 28 cm of stem diameter, and then be girdled on the yellow - green or blue - green stem segments and covered with 100 mg/L ABT - 1 rooting powder. After 40 ~ 50 days, when the bandaged stem showed epidermis uplifts or white root points, the branch could be cut from the parent tree and planted in the substrate for root culture.

  8. Use of auxin, fungicides and rooting cofactors to induce adventitious root formation in softwood cuttings of apple, gooseberry and some ornamental plants

    Directory of Open Access Journals (Sweden)

    M. G. Piątkowski

    2015-06-01

    Full Text Available Cuttings of apple rootstocks MM 106, Alnarp 2, M VII and M 26, of the ornamental plants Pyracantha coccinea Roem., Syringa Meyeri Schneid., and Weigela cv. Vanhouttei formed a larger numbers of adventitious roots with a mixture of naphthaleneacetic acid and the fungicide Captan than with auxin alone. Boric acid, vitamin B1 as well as pyrogallol and vanilic acid in rather high concentrations showed no effect on rooting when used separately or in a mixture with an auxin. Intermittent mist and bottom heat were used.

  9. Context-Dependent Development of Lymphoid Stroma from Adult CD34+ Adventitial Progenitors

    DEFF Research Database (Denmark)

    Sitnik, Katarzyna Maria; Wendland, Kerstin; Weishaupt, Holger;

    2016-01-01

    ) and thymus that is located within the vascular niche surrounding PDPN-PDGFRβ+/α-Esam-1+ITGA7+ pericytes. CD34+ adventitial cells developed in late embryonic thymus and in postnatal LNs and in the thymus originated, along with pericytes, from a common anlage-seeding progenitor population. Using lymphoid organ...

  10. Production of biomass and bioactive compounds from adventitious roots by optimization of culturing conditions of Eurycoma longifolia in balloon-type bubble bioreactor system.

    Science.gov (United States)

    Lulu, Tao; Park, So-Young; Ibrahim, Rusli; Paek, Kee-Yoeup

    2015-06-01

    The present study aimed to optimize the conditions for the production of adventitious roots from Eurycoma longifolia Jack, an important medicinal woody plant, in bioreactor culture. The effects of the type and concentration of auxin on root growth were studied, as well as the effects of the NH4(+):NO3(-) ratio on adventitious root growth and the production of phenolics and flavonoids. Approximately 5 g L(-1) fresh weight of adventitious roots was inoculated into a 3 L balloon-type bubble bioreactor, which contained 2 L 3/4 MS medium supplemented with 30 g L(-1) sucrose and cultures were maintained in the dark for 7 weeks at 24 ± 1°C. Higher concentrations of IBA (7.0 and 9.0 mg L(-1)) and NAA (5.0 mg L(-1)) enhanced the biomass and accumulation of total phenolics and flavonoids. The adventitious roots were thin, numerous, and elongated in 3/4 MS medium supplemented with 5.0 and 7.0 mg L(-1) IBA, whereas the lateral roots were shorter and thicker with 5.0 mg L(-1) NAA compared with IBA treatment. The optimum biomasses of 50.22 g L(-1) fresh weight and 4.60 g L(-1) dry weight were obtained with an NH4(+):NO3(-) ratio of 15:30. High phenolic and flavonoid productions (38.59 and 11.27 mg L(-1) medium, respectively) were also obtained with a ratio of 15:30. Analysis of the 2,2-diphenyl-1-picrylhydrazyl (DPPH)-scavenging activity indicated higher antioxidant activity with an NH4(+):NO3(-) ratio of 30:15. These results suggest that balloon-type bubble bioreactor cultures are suitable for the large-scale commercial production of E. longifolia adventitious roots which contain high yield of bioactive compounds.

  11. Effect of Naphthalene Acetic Acid on the Adventitious Rooting in Shoot Cuttings of Andrographis paniculata (Burm.f. Wall. ex Nees: An Important Therapeutical Herb

    Directory of Open Access Journals (Sweden)

    Md. Sanower Hossain

    2016-01-01

    Full Text Available Andrographis paniculata is one of the most important therapeutical herbs, widely used in traditional medical systems for the treatment of diverse diseases for thousands of years. This study was carried out to assess the effect of 1-naphthaleneacetic acid (NAA on adventitious rooting in A. paniculata shoot cuttings. The cuttings were treated with six concentrations of NAA (0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 mM by applying soaking method and cuttings without hormone (soaking in distilled water were considered as control. The cuttings were then inoculated into peat moss in the planting tray and incubated under complete shade for root induction. Water was sprayed on peat moss once daily to moisten it. The results showed that different concentrations of NAA significantly (P≤0.05 affected the rooting characteristics of A. paniculata and 2.5 mM of NAA was found to be more effective to induce rooting in young apical shoot (YAS cuttings compared to other concentrations and old apical shoot (OAS. This study also postulates that adventitious rooting response depends on the juvenility of plant material and concentration of growth regulator. This report describes a technique for adventitious rooting in A. paniculata, which could be feasible to use for commercial scale propagation of this plant.

  12. A Co-Opted Hormonal Cascade Activates Dormant Adventitious Root Primordia upon Flooding in Solanum dulcamara1[OPEN

    Science.gov (United States)

    Dawood, Thikra; Kensche, Philip R.; Cristescu, Simona M.; Mariani, Celestina

    2016-01-01

    Soil flooding is a common stress factor affecting plants. To sustain root function in the hypoxic environment, flooding-tolerant plants may form new, aerenchymatous adventitious roots (ARs), originating from preformed, dormant primordia on the stem. We investigated the signaling pathway behind AR primordium reactivation in the dicot species Solanum dulcamara. Transcriptome analysis indicated that flooding imposes a state of quiescence on the stem tissue, while increasing cellular activity in the AR primordia. Flooding led to ethylene accumulation in the lower stem region and subsequently to a drop in abscisic acid (ABA) level in both stem and AR primordia tissue. Whereas ABA treatment prevented activation of AR primordia by flooding, inhibition of ABA synthesis was sufficient to activate them in absence of flooding. Together, this reveals that there is a highly tissue-specific response to reduced ABA levels. The central role for ABA in the response differentiates the pathway identified here from the AR emergence pathway known from rice (Oryza sativa). Flooding and ethylene treatment also induced expression of the polar auxin transporter PIN2, and silencing of this gene or chemical inhibition of auxin transport inhibited primordium activation, even though ABA levels were reduced. Auxin treatment, however, was not sufficient for AR emergence, indicating that the auxin pathway acts in parallel with the requirement for ABA reduction. In conclusion, adaptation of S. dulcamara to wet habitats involved co-option of a hormonal signaling cascade well known to regulate shoot growth responses, to direct a root developmental program upon soil flooding. PMID:26850278

  13. Context-Dependent Development of Lymphoid Stroma from Adult CD34+ Adventitial Progenitors

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    Katarzyna M. Sitnik

    2016-03-01

    Full Text Available Despite the key role of primary and secondary lymphoid organ stroma in immunity, our understanding of the heterogeneity and ontogeny of these cells remains limited. Here, we identify a functionally distinct subset of BP3−PDPN+PDGFRβ+/α+CD34+ stromal adventitial cells in both lymph nodes (LNs and thymus that is located within the vascular niche surrounding PDPN−PDGFRβ+/α−Esam-1+ITGA7+ pericytes. CD34+ adventitial cells developed in late embryonic thymus and in postnatal LNs and in the thymus originated, along with pericytes, from a common anlage-seeding progenitor population. Using lymphoid organ re-aggregate grafts, we demonstrate that adult CD34+ adventitial cells are capable of differentiating into multiple lymphoid stroma-like subsets including pericyte-, FRC-, MRC-, and FDC-like cells, the development of which was lymphoid environment-dependent. These findings extend the current understanding of lymphoid mesenchymal cell heterogeneity and highlight a role of the CD34+ adventitia as a potential ubiquitous source of lymphoid stromal precursors in postnatal tissues.

  14. Molecular cloning and expression of a cucumber (Cucumis sativus L.) heme oxygenase-1 gene, CsHO1, which is involved in adventitious root formation.

    Science.gov (United States)

    Li, Mei-Yue; Cao, Ze-Yu; Shen, Wen-Biao; Cui, Jin

    2011-10-15

    Our previous work showed that in cucumber (Cucumis sativus), auxin rapidly induces heme oxygenase (HO) activity and the product of HO action, carbon monoxide (CO), then triggers the signal transduction events leading to adventitious root formation. In this study, the cucumber HO-1 gene (named as CsHO1) was isolated and sequenced. It contains four exons and three introns and encodes a polypeptide of 291 amino acids. Further results show that CsHO1 shares a high homology with plant HO-1 proteins and codes a 33.3 kDa protein with a 65-amino transit peptide, predicting a mature protein of 26.1 kDa. The mature CsHO1 was expressed in Escherichia coli to produce a fusion protein, which exhibits HO activity. The CsHO1:GFP fusion protein was localized in the chloroplast. Related biochemical analyses of mature CsHO1, including Vmax, Km, Topt and pHopt, were also investigated. CsHO1 mRNA was found in germinating seeds, roots, stem, and especially in leaf tissues. Several well-known adventitious root inducers, including auxin, ABA, hemin, nitric oxide donor sodium nitroprusside (SNP), CaCl(2), and sodium hydrosulfide (NaHS), differentially up-regulate CsHO1 transcripts and corresponding protein levels. These results suggest that CsHO1 may be involved in cucumber adventitious rooting.

  15. 太子参不定根组织培养的研究%Study on tissue cultivation of adventitious roots of Pseudoxtellariae heterophylla

    Institute of Scientific and Technical Information of China (English)

    梁玉勇; 尹双双; 左北梅; 高文远

    2012-01-01

    Objective: To systematically optimize the cultivation conditions of adventitious roots of Pseudoxtellariae heterophylla. Method: Tissue cultivation technology and ultraviolet spectrophotometry were adopted to observe the effect of inoculum volume, sucrose concentration, inorganic salt concentration, number of cultivation days, gradual scale-up cultivation and bubble different angles of bioreactor on the growth of adventitious roots of P. heterophylla, and determine the content of constituents such as saponin, polysaccha-ride and amino acid. Result: The propagation multiple of adventitious roots reached the maximum when the inoculum was 6 g in a 1 L culture shake flask. With the increase in sucrose concentration, the dry weight propagation multiples of adventitious roots followed an up and down trend. The inorganic salt concentration in a cultivation dish had a greater effect on the growth of adventitious roots, particularly 3/4 MS was the most favorable for the growth of adventitious roots. The growth curve of P. heterophylla was " S" , with the bio-mass reaching the maximum at the 28th day. Conclusion: The inoculum volume, sucrose concentration, inorganic salt concentration, gradual scale-up cultivation and angles of bubble bioreactor had a significant effect on the growth of adventitious roots of P. heterophylla. The contents of saponin and amino acid in adventitious roots were higher than that in cultivated P. heterophylla, whereas the poly-saccharide content were lower than that in cultivated P. heterophylla.%目的:对太子参不定根的培养条件进行系统的优化.方法:利用组织培养技术结合紫外分光光度法,考察了接种量、蔗糖浓度、无机盐浓度、培养天数、逐级扩大培养以及不同角度鼓泡式反应器对太子参不定根生长的影响,并对不定根中皂苷、多糖和氨基酸等成分进行含量测定.结果:每1L培养基接种的不定根鲜重为6 g时,太子参不定根的干重增殖倍数达到

  16. A higher sink competitiveness of the rooting zone and invertases are involved in dark stimulation of adventitious root formation in Petunia hybrida cuttings.

    Science.gov (United States)

    Klopotek, Yvonne; Franken, Philipp; Klaering, Hans-Peter; Fischer, Kerstin; Hause, Bettina; Hajirezaei, Mohammad-Reza; Druege, Uwe

    2016-02-01

    The contribution of carbon assimilation and allocation and of invertases to the stimulation of adventitious root formation in response to a dark pre-exposure of petunia cuttings was investigated, considering the rooting zone (stem base) and the shoot apex as competing sinks. Dark exposure had no effect on photosynthesis and dark respiration during the subsequent light period, but promoted dry matter partitioning to the roots. Under darkness, higher activities of cytosolic and vacuolar invertases were maintained in both tissues when compared to cuttings under light. This was partially associated with higher RNA levels of respective genes. However, activity of cell wall invertases and transcript levels of one cell wall invertase isogene increased specifically in the stem base during the first two days after cutting excision under both light and darkness. During five days after excision, RNA accumulation of four invertase genes indicated preferential expression in the stem base compared to the apex. Darkness shifted the balance of expression of one cytosolic and two vacuolar invertase genes towards the stem base. The results indicate that dark exposure before planting enhances the carbon sink competitiveness of the rooting zone and that expression and activity of invertases contribute to the shift in carbon allocation.

  17. Anatomic characteristics of transverse lateral roots and adventitious buds of Populus euphratica%胡杨横走侧根及不定芽发生的形态解剖学研究

    Institute of Scientific and Technical Information of China (English)

    李志军; 焦培培; 周正立; 李倩; 李健强

    2011-01-01

    Anatomic characteristics of clonal growth of root suckers of Populus euphratica was studied by means of conventional paraffin method.The results show that primary xylems of transverse lateral roots are triarch or tetrarch,with developed phelloderm in periderm,and formed by six to eight layers of parenchymatous cells.The proportion of secondary phloem,located in the secondary vascular tissue of cross-sections of transverse lateral roots,is significantly less than secondary xylem.The early generated secondary xylems are characterized by the majority of nonwoody wood fiber cell in cell wall,and vascular ray well develops.The clonal growth of root suckers of P.euphratica is due to the development and growth of adventitious buds on transverse lateral roots.Adventitious buds originate from cork cambium of transverse lateral roots,and cork cambium cells form primordia of adventitious buds by cell division.The cell division,proliferation and differentiation of adventitious primordium formed visible primordia on the surface of transverse lateral roots,and these primordia directly develop as root suckers.Primordia present temporal characteristics of synchronous and asynchronous generation,and spatial characteristics of simple-point and multi-point gathering generation.The base of adventitious primordia could generate new sub-primordia during its growth process.This is the key reason that clonal growth of root suckers caused root suckers growing in different sizes and the densely fasciculate shape.It also indicated that P.euphratica had strong ability of clonal growth of root suckers.%利用常规石蜡切片法对胡杨根蘖繁殖特性进行形态解剖学研究。结果表明:胡杨横走侧根的初生木质部为三原型或四原型,周皮中栓内层较发达,由6~8层薄壁细胞组成。横走侧根横切面上次生维管组织中次生韧皮部的比例远小于次生木质部;早期形成的次生木质部以细胞壁尚未木质化的木纤维细胞数量

  18. Transcriptomic analysis reveals ethylene as stimulator and auxin as regulator of adventitious root formation in petunia cuttings

    Directory of Open Access Journals (Sweden)

    Uwe eDruege

    2014-09-01

    Full Text Available Adventitious root (AR formation in the stem base of cuttings is the basis for propagation of many plant species and petunia is used as model to study this developmental process. Following AR formation from 2 to 192 hours after excision (hpe of cuttings, transcriptome analysis by microarray revealed a change of the character of the rooting zone from stem base to root identity. The greatest shift in the number of differentially expressed genes was observed between 24 and 72 hpe, when the categories storage, mineral nutrient acquisition, anti-oxidative and secondary metabolism, and biotic stimuli showed a notable high number of induced genes. Analyses of phytohormone-related genes disclosed multifaceted changes of the auxin transport system, auxin conjugation and the auxin signal perception machinery indicating a reduction in auxin sensitivity and phase-specific responses of particular auxin-regulated genes. Genes involved in ethylene biosynthesis and action showed a more uniform pattern as a high number of respective genes were generally induced during the whole process of AR formation. The important role of ethylene for stimulating AR formation was demonstrated by the application of inhibitors of ethylene biosynthesis and perception as well as of the precursor aminocyclopropane-1-carboxylic acid, all changing the number and length of AR. A model is proposed showing the putative role of polar auxin transport and resulting auxin accumulation in initiation of subsequent changes in auxin homeostasis and signal perception with a particular role of Aux/IAA expression. These changes might in turn guide the entrance into the different phases of AR formation. Ethylene biosynthesis, which is stimulated by wounding and does probably also respond to other stresses and auxin, acts as important stimulator of AR formation probably via the expression of ethylene responsive transcription factor genes, whereas the timing of different phases seems to be controlled

  19. Identification of genes involved in indole-3-butyric acid-induced adventitious root formation in nodal cuttings of Camellia sinensis (L.) by suppression subtractive hybridization.

    Science.gov (United States)

    Wei, Kang; Wang, Liyuan; Cheng, Hao; Zhang, Chengcai; Ma, Chunlei; Zhang, Liqun; Gong, Wuyun; Wu, Liyun

    2013-02-10

    The plant hormone auxin plays a key role in adventitious rooting. To increase our understanding of genes involved in adventitious root formation, we identified transcripts differentially expressed in single nodal cuttings of Camellia sinensis treated with or without indole-3-butyric acid (IBA) by suppressive subtractive hybridization (SSH). A total of 77 differentially expressed transcripts, including 70 up-regulated and 7 down-regulated sequences, were identified in tea cuttings under IBA treatment. Seven candidate transcripts were selected and analyzed for their response to IBA, and IAA by real time RT-PCR. All these transcripts were up regulated by at least two folds one day after IBA treatment. Meanwhile, IAA showed less positive effects on the expression of candidate transcripts. The full-length cDNA of a F-box/kelch gene was also isolated and found to be similar to a group of At1g23390 like genes. These unigenes provided a new source for mining genes related to adventitious root formation, which facilitate our understanding of relative fundamental metabolism.

  20. Transcriptome Analysis of Methyl Jasmonate-Elicited Panax ginseng Adventitious Roots to Discover Putative Ginsenoside Biosynthesis and Transport Genes

    Directory of Open Access Journals (Sweden)

    Hongzhe Cao

    2015-01-01

    Full Text Available The Panax ginseng C.A. Meyer belonging to the Araliaceae has long been used as an herbal medicine. Although public databases are presently available for this family, no methyl jasmonate (MeJA elicited transcriptomic information was previously reported on this species, with the exception of a few expressed sequence tags (ESTs using the traditional Sanger method. Here, approximately 53 million clean reads of adventitious root transcriptome were separately filtered via Illumina HiSeq™2000 from two samples treated with MeJA (Pg-MeJA and equal volumes of solvent, ethanol (Pg-Con. Jointly, a total of 71,095 all-unigenes from both samples were assembled and annotated, and based on sequence similarity search with known proteins, a total of 56,668 unigenes was obtained. Out of these annotated unigenes, 54,920 were assigned to the NCBI non-redundant protein (Nr database, 35,448 to the Swiss-prot database, 43,051 to gene ontology (GO, and 19,986 to clusters of orthologous groups (COG. Searching in the Kyoto encyclopedia of genes and genomes (KEGG pathway database indicated that 32,200 unigenes were mapped to 128 KEGG pathways. Moreover, we obtained several genes showing a wide range of expression levels. We also identified a total of 749 ginsenoside biosynthetic enzyme genes and 12 promising pleiotropic drug resistance (PDR genes related to ginsenoside transport.

  1. Comprehensive transcriptome analysis unravels the existence of crucial genes regulating primary metabolism during adventitious root formation in Petunia hybrida.

    Directory of Open Access Journals (Sweden)

    Amirhossein Ahkami

    Full Text Available To identify specific genes determining the initiation and formation of adventitious roots (AR, a microarray-based transcriptome analysis in the stem base of the cuttings of Petunia hybrida (line W115 was conducted. A microarray carrying 24,816 unique, non-redundant annotated sequences was hybridized to probes derived from different stages of AR formation. After exclusion of wound-responsive and root-regulated genes, 1,354 of them were identified which were significantly and specifically induced during various phases of AR formation. Based on a recent physiological model distinguishing three metabolic phases in AR formation, the present paper focuses on the response of genes related to particular metabolic pathways. Key genes involved in primary carbohydrate metabolism such as those mediating apoplastic sucrose unloading were induced at the early sink establishment phase of AR formation. Transcriptome changes also pointed to a possible role of trehalose metabolism and SnRK1 (sucrose non-fermenting 1- related protein kinase in sugar sensing during this early step of AR formation. Symplastic sucrose unloading and nucleotide biosynthesis were the major processes induced during the later recovery and maintenance phases. Moreover, transcripts involved in peroxisomal beta-oxidation were up-regulated during different phases of AR formation. In addition to metabolic pathways, the analysis revealed the activation of cell division at the two later phases and in particular the induction of G1-specific genes in the maintenance phase. Furthermore, results point towards a specific demand for certain mineral nutrients starting in the recovery phase.

  2. Aspergillus niger Enhance Bioactive Compounds Biosynthesis As Well As Expression of Functional Genes in Adventitious Roots of Glycyrrhiza uralensis Fisch.

    Science.gov (United States)

    Li, Jing; Wang, Juan; Li, Jinxin; Liu, Dahui; Li, Hongfa; Gao, Wenyuan; Li, Jianli; Liu, Shujie

    2016-02-01

    In the present study, the culture conditions for the accumulation of Glycyrrhiza uralensis adventitious root metabolites in balloon-type bubble bioreactors (BTBBs) have been optimized. The results of the culture showed that the best culture conditions were a cone angle of 90° bioreactor and 0.4-0.6-0.4-vvm aeration volume. Aspergillus niger can be used as a fungal elicitor to enhance the production of defense compounds in plants. With the addition of a fungal elicitor (derived from Aspergillus niger), the maximum accumulation of total flavonoids (16.12 mg g(-1)) and glycyrrhetinic acid (0.18 mg g(-1)) occurred at a dose of 400 mg L(-1) of Aspergillus niger resulting in a 3.47-fold and 1.8-fold increase over control roots. However, the highest concentration of polysaccharide (106.06 mg g(-1)) was achieved with a mixture of elicitors (Aspergillus niger and salicylic acid) added to the medium, resulting in a 1.09-fold increase over Aspergillus niger treatment alone. Electrospray ionization tandem mass spectrometry (ESI-MS(n)) analysis was performed, showing that seven compounds were present after treatment with the elicitors, including uralsaponin B, licorice saponin B2, liquiritin, and (3R)-vestitol, only identified in the mixed elicitor treatment group. It has also been found that elicitors (Aspergillus niger and salicylic acid) significantly upregulated the expression of the cinnamate 4-hydroxylase (C4H), β-amyrin synthase (β-AS), squalene epoxidase (SE) and a cytochrome P450 monooxygenase (CYP72A154) genes, which are involved in the biosynthesis of bioactive compounds, and increased superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activity.

  3. Changes in endogenous hormone levels and redox status during enhanced adventitious rooting by rare earth element neodymium of Dendrobium densiflorum shoot cuttings

    Institute of Scientific and Technical Information of China (English)

    LUO Jianping; ZHANG Jingcheng; WANG Ying

    2008-01-01

    The effects of neodymium nitrate (Nd3+) on the adventitious rooting of Dendrobium densiflorum shoot cuttings were studied. The addition of Nd3+ (5 μmol/L) to culture medium significantly increased rooting frequency. Histological investigation showed that Nd3+ did not change the process of root initiation. Nd3+ did not influence total endogenous cytokinin levels, but significantly increased the level of en-dogenous indole-3-acetic acid (IAA) in the base of shoot cuttings. Compared to the control, the ratio of IAA/cytokinins was very high in the Nd3+ treatment. These results suggested that the enhanced rooting frequency may be related to the increase in endogenous IAA level in Nd3+ treatment. Analysis of enzyme activities showed that the enhanced accumulation of the endogenous IAA by Nd3+ should not be attributed to inhibition of IAA decomposition by IAA oxidase or promotion of cytokinin decomposition by cytokinin oxidase. Besides, Nd3+ increased the ratio of reduced glutathione (GSH) and oxidized glutathione (GSSG) in the process of adventitious rooting while the ratio of ascorbate (ASC) to dehydroascorbate (DHA) was not affected.

  4. Enhancement of anti-inflammatory activity of Aloe vera adventitious root extracts through the alteration of primary and secondary metabolites via salicylic acid elicitation.

    Directory of Open Access Journals (Sweden)

    Yun Sun Lee

    Full Text Available Aloe vera (Asphodeloideae is a medicinal plant in which useful secondary metabolites are plentiful. Among the representative secondary metabolites of Aloe vera are the anthraquinones including aloe emodin and chrysophanol, which are tricyclic aromatic quinones synthesized via a plant-specific type III polyketide biosynthesis pathway. However, it is not yet clear which cellular responses can induce the pathway, leading to production of tricyclic aromatic quinones. In this study, we examined the effect of endogenous elicitors on the type III polyketide biosynthesis pathway and identified the metabolic changes induced in elicitor-treated Aloe vera adventitious roots. Salicylic acid, methyl jasmonate, and ethephon were used to treat Aloe vera adventitious roots cultured on MS liquid media with 0.3 mg/L IBA for 35 days. Aloe emodin and chrysophanol were remarkably increased by the SA treatment, more than 10-11 and 5-13 fold as compared with untreated control, respectively. Ultra-performance liquid chromatography-electrospray ionization mass spectrometry analysis identified a total of 37 SA-induced compounds, including aloe emodin and chrysophanol, and 3 of the compounds were tentatively identified as tricyclic aromatic quinones. Transcript accumulation analysis of polyketide synthase genes and gas chromatography mass spectrometry showed that these secondary metabolic changes resulted from increased expression of octaketide synthase genes and decreases in malonyl-CoA, which is the precursor for the tricyclic aromatic quinone biosynthesis pathway. In addition, anti-inflammatory activity was enhanced in extracts of SA-treated adventitious roots. Our results suggest that SA has an important role in activation of the plant specific-type III polyketide biosynthetic pathway, and therefore that the efficacy of Aloe vera as medicinal agent can be improved through SA treatment.

  5. Enhancement of anti-inflammatory activity of Aloe vera adventitious root extracts through the alteration of primary and secondary metabolites via salicylic acid elicitation.

    Science.gov (United States)

    Lee, Yun Sun; Ju, Hyun Kyoung; Kim, Yeon Jeong; Lim, Tae-Gyu; Uddin, Md Romij; Kim, Yeon Bok; Baek, Jin Hong; Kwon, Sung Won; Lee, Ki Won; Seo, Hak Soo; Park, Sang Un; Yang, Tae-Jin

    2013-01-01

    Aloe vera (Asphodeloideae) is a medicinal plant in which useful secondary metabolites are plentiful. Among the representative secondary metabolites of Aloe vera are the anthraquinones including aloe emodin and chrysophanol, which are tricyclic aromatic quinones synthesized via a plant-specific type III polyketide biosynthesis pathway. However, it is not yet clear which cellular responses can induce the pathway, leading to production of tricyclic aromatic quinones. In this study, we examined the effect of endogenous elicitors on the type III polyketide biosynthesis pathway and identified the metabolic changes induced in elicitor-treated Aloe vera adventitious roots. Salicylic acid, methyl jasmonate, and ethephon were used to treat Aloe vera adventitious roots cultured on MS liquid media with 0.3 mg/L IBA for 35 days. Aloe emodin and chrysophanol were remarkably increased by the SA treatment, more than 10-11 and 5-13 fold as compared with untreated control, respectively. Ultra-performance liquid chromatography-electrospray ionization mass spectrometry analysis identified a total of 37 SA-induced compounds, including aloe emodin and chrysophanol, and 3 of the compounds were tentatively identified as tricyclic aromatic quinones. Transcript accumulation analysis of polyketide synthase genes and gas chromatography mass spectrometry showed that these secondary metabolic changes resulted from increased expression of octaketide synthase genes and decreases in malonyl-CoA, which is the precursor for the tricyclic aromatic quinone biosynthesis pathway. In addition, anti-inflammatory activity was enhanced in extracts of SA-treated adventitious roots. Our results suggest that SA has an important role in activation of the plant specific-type III polyketide biosynthetic pathway, and therefore that the efficacy of Aloe vera as medicinal agent can be improved through SA treatment.

  6. Cytokinin-induced promotion of root meristem size in the fern Azolla supports a shoot-like origin of euphyllophyte roots

    NARCIS (Netherlands)

    de Vries, Jan; Fischer, Angela Melanie; Roettger, Mayo; Rommel, Sophie; Schluepmann, Henriette; Bräutigam, Andrea; Carlsbecker, Annelie; Gould, Sven Bernhard

    2016-01-01

    The phytohormones cytokinin and auxin orchestrate the root meristem development in angiosperms by determining embryonic bipolarity. Ferns, having the most basal euphyllophyte root, form neither bipolar embryos nor permanent embryonic primary roots but rather an adventitious root system. This raises

  7. Direct reprogramming of adult somatic cells towards adventitious root formation in forest tree species: the effect of the juvenile-adult transition

    Directory of Open Access Journals (Sweden)

    Carmen eDiaz-Sala

    2014-07-01

    Full Text Available Cellular plasticity refers, among others, to the capability of differentiated cells to switch the differentiation process and acquire new fates. One way by which plant cell plasticity is manifested is through de novo regeneration of organs from somatic differentiated cells in an ectopic location. However, switching the developmental program of adult cells prior to organ regeneration is difficult in many plant species, especially in forest tree species. In these species, a decline in the capacity to regenerate shoots, roots or embryos from somatic differentiated cells is associated with tree age and maturation. The decline in the ability to form adventitious roots from stem cuttings is one of the most dramatic effects of maturation, and has been the subject of investigations on the basic nature of the process. Cell fate switches, both in plants and animals, are characterized by remarkable changes in the pattern of gene expression, as cells switch from the characteristic expression pattern of a somatic cell to a new one directing a new developmental pathway. Therefore, determining the way by which cells reset their gene expression pattern is crucial to understand cellular plasticity. The presence of specific cellular signalling pathways or tissue-specific factors underlying the establishment, maintenance and redirection of gene expression patterns in the tissues involved in adventitious root formation could be crucial for cell fate switch and for the control of age-dependent cellular plasticity.

  8. PkMADS1 is a novel MADS box gene regulating adventitious shoot induction and vegetative shoot development in Paulownia kawakamii.

    Science.gov (United States)

    Prakash, A Pavan; Kumar, Prakash P

    2002-01-01

    Direct regeneration of shoot buds in vitro is an important technique in plant genetic manipulation. We describe the isolation and functional characterization of a novel MADS box cDNA (PkMADS1) from Paulownia kawakamii leaf explants undergoing adventitious shoot regeneration. mRNA gel blot analysis confirmed the expression of PkMADS1 in the shoot-forming cultures, but no signal was observed in the callus-forming cultures. PkMADS1 transcripts were also detected in shoot apices, but not in root apices, initial leaf explants or the flower. In situ hybridization revealed that its expression was restricted to developing shoot primordia in the excised leaf cultures, suggesting a role for this gene in adventitious shoot formation. Transgenic Paulownia plants over-expressing the PkMADS1 gene showed some changes in phenotype, such as axillary shoot formation. In the antisense transformants, shoots were stunted and had altered phyllotaxy, and, in some lines, the shoot apical meristem appeared to have been used up early during shoot development. Leaf explants from the antisense transgenic plants showed a tenfold decrease in shoot regeneration compared with explants from sense transformants or wild-type. Our results show that PkMADS1 is a regulator of shoot morphogenesis.

  9. Influence of cytokinins, basal media and pH on adventitious shoot regeneration from excised root cultures of Albizia lebbeck

    Institute of Scientific and Technical Information of China (English)

    Shahnaz Perveen; Ankita Varshney; Mohammad Anis; Ibrahim M.Aref

    2011-01-01

    A highly reproducible and efficient in vitro shoot regeneration system was developed in a potential medicinal plant, Albizia lebbeck using root explants. Root explanns from 15 day-old-aseptic seedlings were cultured on Murashige and Skoog (MS) medium supplemented with different concentrations (0.5, 2.5, 5.0, 7.5 and 10.0 μM) of 6-Benzyladenine (BA),Kinetin (Kn), 2-lsopentenyl adenine (2-iP) singly as well as in combination with α-Naphthalene acetic acid (NAA) (0.1, 0.5, 1.0, 1.5 and 2.0 μM). The highest rate of shoot multiplication (16.0 ± 1.87 for the average shoot number and 5.16 ± 0.38 cm for shoot length) was achieved on MS medium supplemented with 7.5 tM BA and 0.5 tM NAA. The effects of medium type, medium strength, pH and subculture on shoot induction and proliferation were also tested. An average of 21.6±2.87 shoots per explants could be obtained following this protocol. Rooting was achieved on microshoots using half strength MS medium with 2.0 μM Indole-3-butyric acid (IBA) after four weeks of culture. The in vitro raised healthy plantlets were successfully established in earthen pots containing garden soil and grown in greenhouse with >80% survival rate.

  10. Enhanced formation of aerenchyma and induction of a barrier to radial oxygen loss in adventitious roots of Zea nicaraguensis contribute to its waterlogging tolerance as compared with maize (Zea mays ssp. mays).

    Science.gov (United States)

    Abiko, Tomomi; Kotula, Lukasz; Shiono, Katsuhiro; Malik, Al Imran; Colmer, Timothy David; Nakazono, Mikio

    2012-09-01

    Enhancement of oxygen transport from shoot to root tip by the formation of aerenchyma and also a barrier to radial oxygen loss (ROL) in roots is common in waterlogging-tolerant plants. Zea nicaraguensis (teosinte), a wild relative of maize (Zea mays ssp. mays), grows in waterlogged soils. We investigated the formation of aerenchyma and ROL barrier induction in roots of Z. nicaraguensis, in comparison with roots of maize (inbred line Mi29), in a pot soil system and in hydroponics. Furthermore, depositions of suberin in the exodermis/hypodermis and lignin in the epidermis of adventitious roots of Z. nicaraguensis and maize grown in aerated or stagnant deoxygenated nutrient solution were studied. Growth of maize was more adversely affected by low oxygen in the root zone (waterlogged soil or stagnant deoxygenated nutrient solution) compared with Z. nicaraguensis. In stagnant deoxygenated solution, Z. nicaraguensis was superior to maize in transporting oxygen from shoot base to root tip due to formation of larger aerenchyma and a stronger barrier to ROL in adventitious roots. The relationships between the ROL barrier formation and suberin and lignin depositions in roots are discussed. The ROL barrier, in addition to aerenchyma, would contribute to the waterlogging tolerance of Z. nicaraguensis.

  11. Dynamic transcriptional profiling provides insights into tuberous root development in Rehmannia glutinosa

    Directory of Open Access Journals (Sweden)

    Peng eSun

    2015-06-01

    Full Text Available Rehmannia glutinosa, a herb of the Scrophulariaceae family, is widely cultivated in the Northern part of China. The tuberous root has well known medicinal properties; however, yield and quality are threatened by abiotic and biotic stresses. Understanding the molecular process of tuberous root development may help identify novel targets for its control. In the present study, we used Illumina sequencing and de novo assembly strategies to obtain a reference transcriptome that is relevant to tuberous root development. We then conducted RNA-seq quantification analysis to determine gene expression profiles of the adventitious root (AR, thickening adventitious root (TAR, and the developing tuberous root (DTR. Expression profiling identified a total of 6,974 differentially expressed unigenes during root developmental. Bioinformatics analysis and gene expression profiling revealed changes in phenylpropanoid biosynthesis, starch and sucrose metabolism, and plant hormone biosynthesis during root development. Moreover, we identified and allocated putative functions to the genes involved in tuberous root development, including genes related to major carbohydrate metabolism, hormone metabolism, and transcription regulation. The present study provides the initial description of gene expression profiles of AR, TAR, and DTR, which facilitates identification of genes of interest. Moreover, our work provides insights into the molecular mechanisms underlying tuberous root development and may assist in the design and development of improved breeding schemes for different R. glutinosa varieties through genetic manipulation.

  12. Biochemical changes in barberries during adventitious root formation: the role of indole-3-butyric acid and hydrogen peroxide

    Directory of Open Access Journals (Sweden)

    Ali Tehranifar

    2014-03-01

    Full Text Available Peroxidase, polyphenol oxidase (PPO, phenolic compounds and total sugars (TS were investigated during root formation in cuttings of Berberis vulgaris var. asperma (BVA and Berberis thunbergii var. atropurpurea (BTA treated with indole-3-butyric acid (IBA and IBA+H2O2. Rooting was observed on BTA cuttings but not on BVA cuttings. The BTA cuttings treated with IBA and IBA+H2O2 showed higher rooting percentages, number of roots, and root length over the control. Those treated with IBA+H2O2 recorded the lowest peroxidase activity after planting. BTA cuttings treated with IBA+H2O2 showed the highest peroxidase activity at 50 d after planting; BVA cuttings under different treatments showed no significant difference for peroxidase activity at planting time or up to 80 d after planting. PPO activity for the BTA cuttings in the control treatment was lower than for other treatments during root formation. The cuttings in the IBA and IBA+H2O2 treatments showed increased PPO activity from 0 to 50 d after planting and a slight decrease in PPO activity from 60 to 80 d after planting. PPO activity for the BVA cuttings was significantly lower than for BTA during root formation. The BTA cuttings treated with IBA and IBA+H2O2 showed the highest phenolic compound content during root formation. The BVA cuttings displayed higher TS than BTA during the initial stage of root formation. A comparison of the anatomical structure of easy-to-root and difficult-to-root cuttings indicated that physical inhibitors did not affect the rooting capacity of BVA.

  13. An auxin-responsive endogenous peptide regulates root development in Arabidopsis.

    Science.gov (United States)

    Yang, Fengxi; Song, Yu; Yang, Hao; Liu, Zhibin; Zhu, Genfa; Yang, Yi

    2014-07-01

    Auxin plays critical roles in root formation and development. The components involved in this process, however, are not well understood. Here, we newly identified a peptide encoding gene, auxin-responsive endogenous polypeptide 1 (AREP1), which is induced by auxin, and mediates root development in Arabidopsis. Expression of AREP1 was specific to the cotyledon and to root and shoot meristem tissues. Amounts of AREP1 transcripts and AREP1-green fluorescent protein fusion proteins were elevated in response to indoleacetic acid treatment. Suppression of AREP1 through RNAi silencing resulted in reduction of primary root length, increase of lateral root number, and expansion of adventitious roots, compared to the observations in wild-type plants in the presence of auxin. By contrast, transgenic plants overexpressing AREP1 showed enhanced growth of the primary root under auxin treatment. Additionally, root morphology, including lateral root number and adventitious roots, differed greatly between transgenic and wild-type plants. Further analysis indicated that the expression of auxin-responsive genes, such as IAA3, IAA7, IAA17, GH3.2, GH3.3, and SAUR-AC1, was significantly higher in AREP1 RNAi plants, and was slightly lower in AREP1 overexpressing plants than in wild-type plants. These results suggest that the novel endogenous peptide AREP1 plays an important role in the process of auxin-mediated root development.

  14. [Research progress of adventitious respiratory sound signal processing].

    Science.gov (United States)

    Li, Zhenzhen; Wu, Xiaoming

    2013-10-01

    Adventitious respiratory sound signal processing has been an important researching topic in the field of computerized respiratory sound analysis system. In recent years, new progress has been achieved in adventitious respiratory sound signal analysis due to the applications of techniques of non-stationary random signal processing. Algorithm progress of adventitious respiratory sound detections is discussed in detail in this paper. Then the state of art of adventitious respiratory sound analysis is reviewed, and development directions of next phase are pointed out.

  15. An auxin-responsive endogenous peptide regulates root development in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Fengxi Yang; Yu Song; Hao Yang; Zhibin Liu; Genfa Zhu; Yi Yang

    2014-01-01

    Auxin plays critical roles in root formation and development. The components involved in this process, however, are not well understood. Here, we newly identified a peptide encoding gene, auxin-responsive endogenous polypeptide 1 (AREP1), which is induced by auxin, and mediates root development in Arabidopsis. Expression of AREP1 was specific to the cotyledon and to root and shoot meristem tissues. Amounts of AREP1 transcripts and AREP1-green fluorescent protein fusion proteins were elevated in response to indoleacetic acid treatment. Suppression of AREP1 through RNAi silencing resulted in reduction of primary root length, increase of lateral root number, and expansion of adventitious roots, compared to the observations in wild-type plants in the presence of auxin. By contrast, transgenic plants overexpressing AREP1 showed enhanced growth of the primary root under auxin treatment. Additionally, rootmorphology, including lateral root number and adventitious roots, differed greatly between transgenic and wildtype plants. Further analysis indicated that the expression of auxin-responsive genes, such as IAA3, IAA7, IAA17, GH3.2, GH3.3, and SAUR-AC1, was significantly higher in AREP1 RNAi plants, and was slightly lower in AREP1 overexpressing plants than in wildtype plants. These results suggest that the novel endogenous peptide AREP1 plays an important role in the process of auxinmediated root development.

  16. Ectopic expression of class 1 KNOX genes induce adventitious shoot regeneration and alter growth and development of tobacco (Nicotiana tabacum L) and European plum (Prunus domestica L).

    Science.gov (United States)

    Srinivasan, C; Liu, Zongrang; Scorza, Ralph

    2011-04-01

    Transgenic plants of tobacco (Nicotiana tabacum L) and European plum (Prunus domestica L) were produced by transforming with the apple class 1 KNOX genes (MdKN1 and MdKN2) or corn KNOX1 gene. Transgenic tobacco plants were regenerated in vitro from transformed leaf discs cultured in a medium lacking cytokinin. Ectopic expression of KNOX genes retarded shoot growth by suppressing elongation of internodes in transgenic tobacco plants. Expression of each of the three KNOX1 genes induced malformation and extensive lobbing in tobacco leaves. In situ regeneration of adventitious shoots was observed from leaves and roots of transgenic tobacco plants expressing each of the three KNOX genes. In vitro culture of leaf explants and internode sections excised from in vitro grown MdKN1 expressing tobacco shoots regenerated adventitious shoots on MS (Murashige and Skoog 1962) basal medium in the absence of exogenous cytokinin. Transgenic plum plants that expressed the MdKN2 or corn KNOX1 gene grew normally but MdKN1 caused a significant reduction in plant height, leaf shape and size and produced malformed curly leaves. A high frequency of adventitious shoot regeneration (96%) was observed in cultures of leaf explants excised from corn KNOX1-expressing transgenic plum shoots. In contrast to KNOX1-expressing tobacco, leaf and internode explants of corn KNOX1-expressing plum required synthetic cytokinin (thidiazuron) in the culture medium to induce adventitious shoot regeneration. The induction of high-frequency regeneration of adventitious shoots in vitro from leaves and stem internodal sections of plum through the ectopic expression of a KNOX1 gene is the first such report for a woody perennial fruit trees.

  17. GENOME ENABLED MODIFICATION OF POPLAR ROOT DEVELOPMENT FOR INCREASED CARBON SEQUESTRATION

    Energy Technology Data Exchange (ETDEWEB)

    Busov, Victor

    2013-03-05

    grow an increased number of adventitious roots, whereas RNA interference mediated the down-expression of PtAIL1 expression, which led to a delay in adventitious root formation. Microarray analysis showed that the expression of 15 genes, including the transcription factors AGAMOUS-Like6 and MYB36, was overexpressed in the stem tissues that generated root primordia in PtAIL1-overexpressing plants, whereas their expression was reduced in the RNA interference lines. These results demonstrate that PtAIL1 is a positive regulator of poplar rooting that acts early in the development of adventitious roots. Genomes. 7: 91-101 Knowledge of the functional relationship between genes and organismal phenotypes in perennial plants is extremely limited. Using a population of 627 independent events, we assessed the feasibility of activation tagging as a forward genetics tool for Populus. Mutant identification after 2 years of field testing was nearly sevenfold (6.5%) higher than in greenhouse studies that employed Arabidopsis and identical transformation vectors. Approximately two thirds of all mutant phenotypes were not seen in vitro and in the greenhouse; they were discovered only after the second year of field assessment. The trees? large size (5-10 m in height), perennial growth, and interactions with the natural environment are factors that are thought to have contributed to the high rate of observable phenotypes in the field. The mutant phenotypes affected a variety of morphological and physiological traits, including leaf size and morphology, crown architecture, stature, vegetative dormancy, and tropic responses. Characterization of the insertion in more than 100 events with and without mutant phenotypes showed that tags predominantly (70%) inserted in a 13-Kbp region up- and downstream of the genes? coding regions with approximately even distribution among the 19 chromosomes. Transcriptional activation was observed in many proximal genes studied. Successful phenotype

  18. Effects of phenolic compounds on adventitious root formation and oxidative decarboxylation of applied indoleacetic acid in Malus 'Jork 9'

    NARCIS (Netherlands)

    Klerk, de G.J.M.; Guan, H.; Huisman, P.; Marinova, S.

    2011-01-01

    Stem slices (1-mm thick) cut from apple microshoots were cultured on a modified Murashige-Skoog medium with indole-3-acetic acid (IAA) or α-naphthaleneacetic acid (NAA), and increasing concentrations of various phenolic compounds. Both auxins were added at a concentration suboptimal for rooting. Ind

  19. Biochemical Status of Stock Plants and Their Annual Sprouts as a Crucial Key for Successful Adventitious Root Formation

    Directory of Open Access Journals (Sweden)

    Gregor OSTERC

    2015-04-01

    Full Text Available Leafy cuttings of Prunus subhirtella Miq. ‘Autumnalis’ were harvested from mature, semi-mature and juvenile stock plants at four dates during the vegetative period 2011 (on 16th of May, on 30th of May, on 20th of June and on 11th of July and their auxin levels (IAA, IAA-Asp and sugar content (glucose, sucrose, sorbitol were quantified. The IAA and IAA-Asp contents in cutting bases increased over the vegetative period, whereby aspartate values were higher than IAA values. The IAA-Asp values ranged from 6.3 µg g-1 to 22.7 µg g-1 FW and reached two great peaks on 30th of May and on 11th of July. The IAA values ranged from 0.29 µg g-1 to 4.51 µg g-1 FW, reaching a small fall on 20th of June. Significantly higher levels of IAA and IAA-Asp were measured at the base of mature cuttings compared to cuttings of semi-mature and juvenile origin, when the cuttings were harvested on 30th of May and on 11th of July. On the other hand, mature leafy cuttings accumulated significantly less fructose and glucose in their root emergence zone (16.3 g kg-1 DW, 45.2 g kg-1 DW compared to semi-mature cuttings (26.4 g kg-1 DW, 62.5 g kg-1 DW and juvenile cuttings (27.3 g kg-1 DW, 73.9 g kg-1 DW. All measured rooting parameters (rooting success, number of main roots and root length were significantly improved when cuttings of a more juvenile origin (semi-mature and juvenile were used.

  20. Production of the Quinone-Methide Triterpene Maytenin by In Vitro Adventitious Roots of Peritassa campestris (Cambess. A.C.Sm. (Celastraceae and Rapid Detection and Identification by APCI-IT-MS/MS

    Directory of Open Access Journals (Sweden)

    Tiago Antunes Paz

    2013-01-01

    Full Text Available Establishment of adventitious root cultures of Peritassa campestris (Celastraceae was achieved from seed cotyledons cultured in semisolid Woody Plant Medium (WPM supplemented with 2% sucrose, 0.01% PVP, and 4.0 mg L−1 IBA. Culture period on accumulation of biomass and quinone-methide triterpene maytenin in adventitious root were investigated. The accumulation of maytenin in these roots was compared with its accumulation in the roots of seedlings grown in a greenhouse (one year old. A rapid detection and identification of maytenin by direct injection into an atmospheric-pressure chemical ionization ion trap tandem mass spectrometer (APCI-IT-MS/MS were performed without prior chromatographic separation. In vitro, the greatest accumulation of biomass occurred within 60 days of culture. The highest level of maytenin—972.11 μg·g−1 dry weight—was detected at seven days of cultivation; this value was 5.55-fold higher than that found in the roots of seedlings grown in a greenhouse.

  1. 白色紫锥菊不定根诱导及咖啡酸衍生物积累研究%Induction of adventitious roots of Echinacea pallida and accumulation of caffeic acid derivatives

    Institute of Scientific and Technical Information of China (English)

    吴春华; 黄韬; 崔锡花; 白基烨

    2012-01-01

    以白色紫锥菊试管苗子叶为外植体,研究了植物生长素2,4-D,IAA,IBA,NAA对不定根诱导以及IBA浓度对液体悬浮培养中不定根的生长及咖啡酸衍生物积累的影响,并进行了生物反应器培养.结果表明,对白色紫锥不定根诱导最适合植物生长素是IBA1.0mg· L-1,不定根诱导数目达到22.5根/培养皿.液体悬浮培养中IBA 1.0 mg·L-1最适合不定根生长及咖啡酸衍生物的积累.白色紫锥菊不定根在5L气升式生物反应器中培养30 d后可获得8.98 g· L-1干重,是三角瓶悬浮培养干重4.38 g·L-1的2.05倍;生物反应器培养的不定根中紫锥菊苷质量分数为14.08 mg·g-1(干重),是栽培根的2.4倍;氯原酸,菊苣酸,总咖啡酸衍生物含量是栽培根的4.0 ~25.6倍.该研究为大量生产紫锥菊药品可提供富含紫锥菊苷等咖啡酸衍生物的高品质生物医学药材.%Objective:To investigate the effect of auxins 2,4-D, IAA, IBA, NAA on induction of adventitious roots as well as that of IBA concentrations on the growth of adventitious roots and the accumulation of caffeic acid derivatives, with test-tube seedling leaves Echinacea pallida as the explant,and cultivate adventitious roots in bioreactors. Result: 1.0 mg·L-1 IBA was found the best for the induction of adventitious roots,with the numer of induced adventitious roots up to 22. 5 in each culture dish. Among different concentrations for suspension cultivation of IBA tested, 1. 0 mg·L-1lBA was found the most suitable for the growth of adventitious roots and the accumulation of caffeic acid derivatives. In a 5 L balloon type bubble bioreactor,8. 98 g·L-1 dry weight was achieved after one month,which was 2. 05 times of 4. 38 g·L-1 dry weight cultivated in a triangular flask. The content of echinacoside cultivated in a bioreactor was 14. 08 mg g -1 DW, which was 2. 4 times of cultivated roots. The contents of chlorogenic acid, chicoric acid and total caffeic acid derivatives were

  2. Molecular cloning and characterization of the genes encoding an auxin efflux carrier and the auxin influx carriers associated with the adventitious root formation in mango (Mangifera indica L.) cotyledon segments.

    Science.gov (United States)

    Li, Yun-He; Zou, Ming-Hong; Feng, Bi-Hong; Huang, Xia; Zhang, Zhi; Sun, Guang-Ming

    2012-06-01

    Polar auxin transport (PAT) plays an important role in the adventitious root formation of mango cotyledon segments, but the molecular mechanism remains unclear. In this study, we cloned a gene encoding an auxin efflux carrier (designated as MiPIN1), and we cloned four genes encoding auxin influx carriers (designated as MiAUX1, MiAUX2, MiAUX3 and MiAUX4). The results of a phylogenetic tree analysis indicated that MiPIN1 and the MiAUXs belong to plant PIN and AUXs/LAXs groups. Quantitative real-time PCR indicated that the expression of MiPIN1 and the MiAUXs was lowest at 0 days but sharply increased on and after day 4. During the root formation in the mango cotyledon segments, the MiPIN1 expression in the distal cut surface (DCS) was always higher than the expression in the proximal cut surface (PCS) whereas the expression of the MiAUXs in the PCS was usually higher than in the DCS. This expression pattern might be result in the PAT from the DCS to the PCS, which is essential for the adventitious root formation in the PCS. Our previous study indicated that a pre-treatment of embryos with indole-3-butyric acid (IBA) significantly promoted adventitious rooting in PCS whereas a pre-treatment with 2,3,5-triiodobenzoic acid (TIBA) completely inhibited this rooting. In this study, however, IBA and TIBA pre-treatments slightly changed the expression of MiPIN1. In contrast, while the MiAUX3 and MiAUX4 expression levels were significantly up-regulated by the IBA pre-treatment, the expression levels were down-regulated by the TIBA pre-treatment. These findings imply that MiAUX3 and MiAUX4 are more sensitive to the IBA and TIBA treatments and that they might play important roles during adventitious root formation in mango cotyledon segments.

  3. Comparison of Harpagoside Yield of Callus, Adventitious Root and Endophytes in Scrophulariae Radix%玄参愈伤、不定根和内生菌产哈巴俄苷的比较

    Institute of Scientific and Technical Information of China (English)

    张林甦; 赵德刚

    2012-01-01

    Objective: Inducing callus and adventitious root from Scrophulariae Radix; isolating endophytes; and comparing Hapagoside yield of the different parts of Scrophulariae Radix. Method; Tender leafs of Scrophulariae Radix were cut into small pieces and sterilized to inoculate on MS, N6 mediums with different plant hormones to induce callus; Liquid medium were used in adventitious root inducing and medium transformed according to growing phase during the culture process; general method was used in endophytes isolated. Hapagoside detected with UV spectrophotometry at the wave length 255 nm. Result; Moderate density callus were induced with MS + NAA 0. 05 or 0. 2 or 2 mg -L-1 + 6-BA 2 mg -L-1' medium; mass adventitious roots obtained after 30 d ' s vibrate cultivation; 4 strains of endophytes produce hapagoside were isolated from Radix Scrophulariae root; hapagoside content of callus, adventitious root and fermentation liquor of the four endophyte straints in orderly are 0. 411 , 0. 099 5 , 0. 451, 0. 444 , 0. 489 , 0. 440 g -L-1. Conclusion: Content of hapagoside in callus is 4 times than that of adventitious root; endophytes can yield almost the same amount hapagoside as callus, and have great potential in producing secondary metabolites.%目的:诱导玄参愈伤、不定根产生,分离内生菌,并比较其中有效成分哈巴俄苷的含量.方法:玄参嫩叶片消毒切成小块接种于含不同激素水平的MS,N6培养基诱导愈伤;不定根诱导采用液体培养:将愈伤小块先转入不含激素MS液体培养基,100 r·min-1室温震荡培养,待开始出现不定根后转入含0.05 mg·L-1 NAA+2 mg·L-1 6-BA的MS液体培养基继续震荡培养,内生菌分离采用常规方法.哈巴俄苷含量测定采用紫外分光光度法,测定波长255 nm.结果:MS培养基+NAA0.05,0.2,2 mg·L-1 +6-BA 2 mg·L-1均能诱导出质地较疏松、生长较快的愈伤组织;接种1.5g愈伤30 d左右可得到100 mL满瓶不定根;从玄参鲜块根分离出4

  4. Developmental role of phenylalanine-ammonia-lyase (PAL) and cinnamate 4-hydroxylase (C4H) genes during adventitious rooting of Juglans regia L. microshoots.

    Science.gov (United States)

    Cheniany, Monireh; Ganjeali, Ali

    2016-12-01

    Phenylalanine-ammonia-lyase and cinnamate-4-hydroxylase play important role in the phenylpropanoid pathway, which produces many biologically important secondary metabolites participating in normal plant development. Flavonol quercetin is the main representant of these compounds that has been identified in numerous Juglans spp. In this survey, the developmental expression patterns of PAL and C4H genes during in vitro rooting of two walnut cultivars 'Sunland' and 'Howard' was examined by RT-PCR. To understand the potential role in rooting, the changing pattern of endogenous content of quercetin was also analyzed by HPLC. The 'Sunland' with better capacity to root had more quercetin content during the "inductive phase" of rooting than 'Howard'. In each cultivar, the level of PAL transcripts showed the same behavior with the changing patterns of quercetin during root formation of microshoots. The positive correlation between the changes of quercetin and PAL-mRNA indicated that PAL gene may have an immediate effect on flavonoid pathway metabolites including quercetin. Although the behavioral change of C4H expression was similar in both cultivars during root formation (with significantly more level for 'Howard'), it was not coincide with the changes of quercerin concentrations. Our results showed that C4H function is important for the normal development, but its transcriptional regulation does not correlate with quercetin as an efficient phenolic compound for walnut rhizogenesis.

  5. 芒果子叶切段不定根形成的影响因素分析%Factors of Influencing Adventitious Root Formation of Cotyledon Segments in Mango

    Institute of Scientific and Technical Information of China (English)

    李运合; 马杰; 吴永杰; 孙光明

    2011-01-01

    In order to research the factors of influencing adventitious rooting from cut surface of mango cotyledon segments, the segments' rooting abilities of different collect time,different lengths,different cut positions and different varieties were examined. The results showed that rooting ability of cotyledon segments increased with the increase of maturity of fruits, there was no root formation at the 2 cm cotyledon segments from the embryos of 50 and 60 days after flowering. At 70 days after flowering,there was adventitious root formed on PCS (proximal cut surface), the percentage rooting was 28.6%;After that, the rooting ability was increased sharply and reached to 76.7% at 90 days after flowering, but then kept at a steady level until matured at 110 days after flowering. The length (2.0,1.0,0.5 and 0.2 cm) of cotyledon segment from maturated fruits was closely related with the rooting ability:there was no root formed on 0.2 cm segment, whereas roots formed on the other three length segments and the rooting ability increased with the increase of lengths. Compared the rooting abilities of Mangifera indica L. var. Zihua,M. indica L. var. Okrong and Mangifera indica L. var. Zill,all of them were almost same. Cut position of cotyledon segment (i. e. ,close to the proximal or not) has little effect on the rooting.%分别用不同成熟时间、不同取材部位、不同品种、不同大小的芒果子叶切段为外植体进行不定根的诱导,以探讨影响芒果子叶切段不定根形成能力的原因.结果表明,芒果子叶切段的生根能力随着芒果成熟度的增加而逐渐提高,花后50和60 d的2.0 cm长子叶切段都无不定根形成,从花后70 d开始有不定根形成,此时生根率为28.6%,之后其生根能力迅速提高,在花后90 d生根率达到76.7%,之后生根率稳定保持直到110 d果实成熟.成熟芒果的子叶切段长度(2.0、1.0、0.5和0.2 cm)对不定根的形成有显著影响,0.2 cm的子叶切

  6. Development of root hairs

    NARCIS (Netherlands)

    Grierson, C.; Ketelaar, T.

    2004-01-01

    The cytoskeleton is a dynamic filamentous structure composed of at least actin and microtubule networks. Actin and microtubules are no different structurally from their animal and fungal counterparts. However, the strategies of cell differentiation and development in plants require this network to r

  7. Review on Mutation in Lateral Root of Rice

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xia; ZHANG Da; HAO Zaibin

    2011-01-01

    Rice roots include seminal roots, adventitious roots, lateral roots and root hairs, At present, progresses in the research of rice roots have been achieved in many aspects, such as root morphology, root activity, root reaction to various environmental factors as a contribution of root growth and rice yield, the relationship between root growth and stems/leaves/flowers/rice, genetic laws of root characters, etc. However, there are very few researches on lateral root mutant. This paper reviewed progresses of the lateral root mutant of rice from the perspectives of phytomorphology to plant physiology and biochemistry to the gene mapping, consisting of mechanism of developing lateral root of rice, gene cloning and functional analysis of lateral root development, the relationship between auxin and lateral roots, agronomic traits of lateral roots mutant, structure and morphology of root hairs, gravity anomaly of root, redox metabolism and proteomics researches of the mutation in lateral root of rice.

  8. Dynamics of adventitious rooting in mini-cuttings of Eucalyptus benthamii x Eucalyptus dunnii=Dinamica de enraizamento adventício em miniestacas de Eucalyptus benthamii x Eucalyptus dunnii

    Directory of Open Access Journals (Sweden)

    Antônio Natal Gonçalves

    2012-04-01

    Full Text Available It is possible to determine the optimum time for permanence of vegetative propagules (mini-cuttings inside a greenhouse for rooting, and this value can be used to optimize the structure of the nursery. The aim of this study was to determine the dynamics of adventitious rooting in mini-cuttings of three clones of Eucalyptus benthamii x Eucalyptus dunnii. Sprouts of H12, H19 and H20 clones were collected from mini-stumps that were planted in gutters containing sand and grown in a semi-hydroponic system. The basal region of the mini-cuttings was immersed in 2,000 mg L-1 indole-3-butyric acid (IBA solution for 10 seconds. The rooting percentage of the mini-cuttings, the total length of the root system and the rooting rate per mini-cutting were also evaluated at 0 (time of planting, 7, 14, 21, 28, 35, 42, 49 and 56 days. We used logistic and exponential regression to mathematically model the speed of rhizogenesis. The rooting percentage was best represented as a logistic model, and the total length of the root system was best represented as an exponential model. The clones had different speeds of adventitious rooting. The optimum time for permanence of the mini-cuttings inside the greenhouse for rooting was between 35 and 42 days, and varied depending on the genetic material.O tempo ideal de permanência de propágulos vegetativos (miniestacas no interior da casa de vegetação para a rizogênese é possível de ser determinado matematicamente, o que pode otimizar as instalações do viveiro. O objetivo deste estudo foi determinar a dinâmica de enraizamento de miniestacas de três clones de Eucalyptus benthamii x Eucalyptus dunnii. Brotações dos clones H19, H12 e H20 foram coletadas de minicepas plantadas em canaletão com areia e cultivadas sob sistema semi-hidropônico. A região basal da miniestaca foi imersa em solução de 2.000 mg L-1 de ácido indolbutírico (AIB por 10 segundos. A porcentagem de enraizamento de miniestacas, o comprimento

  9. ROOT Status and Future Developments

    CERN Document Server

    Brun, R; Canal, P; Rademakers, Fons; Goto, Masaharu; Canal, Philippe; Brun, Rene

    2003-01-01

    In this talk we will review the major additions and improvements made to the ROOT system in the last 18 months and present our plans for future developments. The additons and improvements range from modifications to the I/O sub-system to allow users to save and restore objects of classes that have not been instrumented by special ROOT macros, to the addition of a geometry package designed for building, browsing, tracking and visualizing detector geometries. Other improvements include enhancements to the quick analysis sub-system (TTree::Draw()), the addition of classes that allow inter-file object references (TRef, TRefArray), better support for templated and STL classes, amelioration of the Automatic Script Compiler and the incorporation of new fitting and mathematical tools. Efforts have also been made to increase the modularity of the ROOT system with the introduction of more abstract interfaces and the development of a plug-in manager. In the near future, we intend to continue the development of PROOF and...

  10. In vitro antifungal activity of extracts obtained from Hypericum perforatum adventitious roots cultured in a mist bioreactor against planktonic cells and biofilm of Malassezia furfur.

    Science.gov (United States)

    Simonetti, Giovanna; Tocci, Noemi; Valletta, Alessio; Brasili, Elisa; D'Auria, Felicia Diodata; Idoux, Alicia; Pasqua, Gabriella

    2016-01-01

    Xanthone-rich extracts from Hypericum perforatum root cultures grown in a Mist Bioreactor as antifungal agents against Malassezia furfur. Extracts of Hypericum perforatum roots grown in a bioreactor showed activity against planktonic cells and biofilm of Malassezia furfur. Dried biomass, obtained from roots grown under controlled conditions in a ROOTec mist bioreactor, has been extracted with solvents of increasing polarity (i.e. chloroform, ethyl acetate and methanol). The methanolic fraction was the richest in xanthones (2.86 ± 0.43 mg g(-1) DW) as revealed by HPLC. The minimal inhibitory concentration of the methanol extract against M. furfur planktonic cells was 16 μg mL(-1). The inhibition percentage of biofilm formation, at a concentration of 16 μg mL(-1), ranged from 14% to 39%. The results show that H. perforatum root extracts could be used as new antifungal agents in the treatment of Malassezia infections.

  11. Factors influencing axillary shoot proliferation and adventitious budding in cedar.

    Science.gov (United States)

    Renau-Morata, Begoña; Ollero, Javier; Arrillaga, Isabel; Segura, Juan

    2005-04-01

    We developed procedures for in vitro cloning of Cedrus atlantica Manetti and C. libani A. Rich explants from juvenile and mature plants. Explant size was one determinant of the frequency of axillary bud break in both species. Shoot tips and nodal explants mainly developed calli, whereas bud sprouting occurred in defoliated microcuttings cultured on a modified Murashige and Skoog medium without growth regulators. Isolation and continuous subculture of sprouted buds on the same medium allowed cloning of microcuttings from C. atlantica and C. libani seedlings and bicentennial C. libani trees, thus providing a desirable alternative for multiplying mature trees that have demonstrated superior characteristics. We also report adventitious bud differentiation from isolated embryos of C. atlantica. Neither auxin treatments nor other methods tested, including infection with Agrobacterium rhizogenes, were effective in inducing root initiation.

  12. Adventitious bud regeneration from the stigma of Sinapis alba L.

    Directory of Open Access Journals (Sweden)

    Elżbieta Zenkteler

    2012-12-01

    Full Text Available Stigmas isolated from flower buds of 'Nakielska' variety of Sinapis alba were used to develop a micropropagation method suitable for breeding of new cultivars. The origin of adventitious bud regeneration was studied on MS medium, under stimulation by bezylaminopurine (BAP in combination with 2,4-D - dichlorophenoxyacetic acid (2,4-D. Histological analysis showed the structure of Sinapis stigma (composed from four types of tissue: papillae, transmitting tissue, parenchyma and vascular bundles and revealed that numerous meristematic centers developed from parenchyma cells in close vicinity of vascular bundles. Buds very quickly appeared on the surface of initial explants and later formed multiplantlets that were easily rooted in the soil.

  13. Adventitious rooting of auxin-treated Lavandula dentata cuttings Enraizamento adventício de estacas de Lavandula dentata tratadas com auxina

    Directory of Open Access Journals (Sweden)

    Claudine Maria de Bona

    2010-05-01

    Full Text Available Lavandula species may be propagated by seeds. However, plants will present expressive variation both in size and essential oil content. Indole-3-butyric acid (IBA is a growth regulator which efficiently stimulates rooting and the objective of this research was to observe the influence of different IBA concentrations on rooting of L. dentata cuttings. Herbaceous cuttings with approximately 10cm in length and around 1/3 of leaf retention had their bases submerged into 0 (control, 500, 1.000, 2.000 or 3.000mg dm-3 of IBA diluted in de-ionized water for 30 seconds and placed in polystyrene foam trays filled with commercial substrate and kept under intermittent mist system. Averages of root number, length of the longest root, fresh and dry root weight, and percentage of rooted cuttings were evaluated after 60 days. There was no significant difference between treatments for the length of root, fresh and dry root weight. The percentage of rooted cuttings increased with IBA concentrations. A quadratic regression was obtained to root number. The 2.000mg dm-3 dose increased the percentage of rooted cuttings and the mean root number per cutting. L. dentata cuttings are easy to root.Espécies de Lavandula podem ser propagadas por sementes. Entretanto, as plantas apresentarão elevada variabilidade em tamanho e em produção de óleo essencial. O ácido indol-3-butírico (AIB é um regulador de crescimento que eficientemente estimula o enraizamento. O objetivo deste trabalho foi observar a influência de diferentes concentrações de AIB no enraizamento de estacas de L. dentata. Estacas herbáceas com aproximadamente 10cm de comprimento e 1/3 de retenção foliar tiveram suas bases submersas em 0 (controle, 500, 1.000, 2.000 ou 3.000mg dm-3 de AIB diluído em água deionizada por 30 segundos e colocadas em bandejas de isopor contendo substrato comercial sob sistema de nebulização intermitente. As médias de número de raízes, comprimento da raiz mais

  14. Adventitial inflammation and its interaction with intimal atherosclerotic lesions

    Directory of Open Access Journals (Sweden)

    Mohammadreza eAkhavanpoor

    2014-08-01

    Full Text Available The presence of adventitial inflammation in correlation with atherosclerotic lesions has been recognized for decades. In the last years, several studies have investigated the relevance and impact of adventitial inflammation on atherogenesis. In the abdominal aorta of elderly Apoe-/- mice, adventitial inflammatory structures were characterized as organized ectopic lymphoid tissue, and therefore termed adventitial tertiary lymphoid organs (ATLOs. These ATLOs possess similarities in development, structure and function to secondary lymphoid organs. A crosstalk between intimal atherosclerotic lesions and ATLOs has been suggested, and several studies could demonstrate a potential role for medial vascular smooth muscle cells in this process. We here review the development, phenotypic characteristics, and function of ATLOs in atherosclerosis. Furthermore, we discuss the possible role of medial vascular smooth muscle cells and their interaction between plaque and ATLOs.

  15. 诱导樱桃试管苗生根的研究%Adventitious root induction of cherry(Prunus cerasus × p· avium ) in vitro

    Institute of Scientific and Technical Information of China (English)

    孙清荣; 孙洪雁

    2000-01-01

    Propagation on vitro with cherry(Prunus cerasus × P. avium )hybrid "S2" showed that culture in dark marked ly affected rooting, IBA and sucrose had smaller effect on rooting.%以甜樱桃和酸樱桃杂种"S2"的试管苗为试材,研究了IBA、蔗糖及暗培养时间对不定根产生的影响。结果表明,暗培养对不定根产生有显著影响,IBA和蔗糖的影响作用较小,获得高生根率的最优组合为1/2 MS+IBA 0.1m/gL+蔗糖3%培养基、暗培养7天。

  16. Fate of HERS during Tooth Root Development

    OpenAIRE

    HUANG, XIAOFENG; BRINGAS, PABLO; Slavkin, Harold C.; Chai, Yang

    2009-01-01

    Tooth root development begins after the completion of crown formation in mammals. Previous studies have shown that Hertwig's epithelial root sheath (HERS) plays an important role in root development, but the fate of HERS has remained unknown. In order to investigate the morphological fate and analyze the dynamic movement of HERS cells in vivo, we generated K14-Cre;R26R mice. HERS cells are detectable on the surface of the root throughout root formation and do not disappear. Most of the HERS c...

  17. Development and Function of Root System of Trapa quadrispinosa Roxb.%四角菱根系的发育和功能

    Institute of Scientific and Technical Information of China (English)

    陆昌燕; 刘体育; 郑兴峰

    2011-01-01

    [ Objective ] This paper aimed to explore the adaptive characteristics of development and function of the root system of Trapa quadrispinosa Roxb. [ Method ] Observation was conducted on the growth and development from the seedling cultivated in artificial water channels, and comparison in the cultivation was done of normal plants and treated plants in three groups of separately excising off adventitious roots,pinnate appendices (special adventitious roots) ,and adventitious roots and pinnate appendices [ Result ] The radical and the pinnate appendices both grew determinately, and the apex of radical presented browning death after the radical stopped growth. The adventitious roots on the base of radical and the node of stem grew downwards and spirally into the tier of soil under water body. The pinnate appendix was generally with four lines of branches in radial symmetry. After only the root,and both the adventitious root and the pinnate appendix were excised off, etiolating of the new floating leaf occurred, however,if only the pinnate appendix was cut away, the new floating leaf kept green. [ Conclusion ] The adventitious root system, which continually arose towards the stem apex along with growth of the stem and was in stead of the root system from the radical, can better fix its plant which was thin and floating in water body, and was with important absorption function. The pinnate appendix was a complementary photosynthetic organ of specialized adventitious root.%[目的]研究四角菱(Trapa quadrispinosa Roxb.)根系的发育和功能适应性特征.[方法]采用人工水槽对四角菱幼苗进行培养观察,设置切除不定根、切除羽状物(特化不定根)以及同时切除不定根和羽状物3个处理,并与正常生长的植株进行对比.[结果]四角菱的胚根和羽状物进行有限生长,胚根停止生长后顶端出现褐化死亡;胚根基部和茎节上的不定根向水底泥层生长,并在泥层中弯曲生

  18. A simple method suitable to study de novo root organogenesis

    Directory of Open Access Journals (Sweden)

    Xiaodong eChen

    2014-05-01

    Full Text Available De novo root organogenesis is the process in which adventitious roots regenerate from detached or wounded plant tissues or organs. In tissue culture, appropriate types and concentrations of plant hormones in the medium are critical for inducing adventitious roots. However, in natural conditions, regeneration from detached organs is likely to rely on endogenous hormones. To investigate the actions of endogenous hormones and the molecular mechanisms guiding de novo root organogenesis, we developed a simple method to imitate natural conditions for adventitious root formation by culturing Arabidopsis thaliana leaf explants on B5 medium without additive hormones. Here we show that the ability of the leaf explants to regenerate roots depends on the age of the leaf and on certain nutrients in the medium. Based on these observations, we provide examples of how this method can be used in different situations, and how it can be optimized. This simple method could be used to investigate the effects of various physiological and molecular changes on the regeneration of adventitious roots. It is also useful for tracing cell lineage during the regeneration process by differential interference contrast observation of -glucuronidase staining, and by live imaging of proteins labeled with fluorescent tags.

  19. GENOME ENABLED MODIFICATION OF POPLAR ROOT DEVELOPMENT FOR INCREASED CARBON SEQUESTRATION

    Energy Technology Data Exchange (ETDEWEB)

    Busov, Victor

    2013-03-05

    grow an increased number of adventitious roots, whereas RNA interference mediated the down-expression of PtAIL1 expression, which led to a delay in adventitious root formation. Microarray analysis showed that the expression of 15 genes, including the transcription factors AGAMOUS-Like6 and MYB36, was overexpressed in the stem tissues that generated root primordia in PtAIL1-overexpressing plants, whereas their expression was reduced in the RNA interference lines. These results demonstrate that PtAIL1 is a positive regulator of poplar rooting that acts early in the development of adventitious roots. Genomes. 7: 91-101 Knowledge of the functional relationship between genes and organismal phenotypes in perennial plants is extremely limited. Using a population of 627 independent events, we assessed the feasibility of activation tagging as a forward genetics tool for Populus. Mutant identification after 2 years of field testing was nearly sevenfold (6.5%) higher than in greenhouse studies that employed Arabidopsis and identical transformation vectors. Approximately two thirds of all mutant phenotypes were not seen in vitro and in the greenhouse; they were discovered only after the second year of field assessment. The trees? large size (5-10 m in height), perennial growth, and interactions with the natural environment are factors that are thought to have contributed to the high rate of observable phenotypes in the field. The mutant phenotypes affected a variety of morphological and physiological traits, including leaf size and morphology, crown architecture, stature, vegetative dormancy, and tropic responses. Characterization of the insertion in more than 100 events with and without mutant phenotypes showed that tags predominantly (70%) inserted in a 13-Kbp region up- and downstream of the genes? coding regions with approximately even distribution among the 19 chromosomes. Transcriptional activation was observed in many proximal genes studied. Successful phenotype

  20. Root development during soil genesis: effects of root-root interactions, mycorrhizae, and substrate

    Science.gov (United States)

    Salinas, A.; Zaharescu, D. G.

    2015-12-01

    A major driver of soil formation is the colonization and transformation of rock by plants and associated microbiota. In turn, substrate chemical composition can also influence the capacity for plant colonization and development. In order to better define these relationships, a mesocosm study was set up to analyze the effect mycorrhizal fungi, plant density and rock have on root development, and to determine the effect of root morphology on weathering and soil formation. We hypothesized that plant-plant and plant-fungi interactions have a stronger influence on root architecture and rock weathering than the substrate composition alone. Buffalo grass (Bouteloua dactyloides) was grown in a controlled environment in columns filled with either granular granite, schist, rhyolite or basalt. Each substrate was given two different treatments, including grass-microbes and grass-microbes-mycorrhizae and incubated for 120, 240, and 480 days. Columns were then extracted and analyzed for root morphology, fine fraction, and pore water major element content. Preliminary results showed that plants produced more biomass in rhyolite, followed by schist, basalt, and granite, indicating that substrate composition is an important driver of root development. In support of our hypothesis, mycorrhizae was a strong driver of root development by stimulating length growth, biomass production, and branching. However, average root length and branching also appeared to decrease in response to high plant density, though this trend was only present among roots with mycorrhizal fungi. Interestingly, fine fraction production was negatively correlated with average root thickness and volume. There is also slight evidence indicating that fine fraction production is more related to substrate composition than root morphology, though this data needs to be further analyzed. Our hope is that the results of this study can one day be applied to agricultural research in order to promote the production of crops

  1. Adventitious shoot formation on leaf cuttings in vivo, a tool in horticulture.

    NARCIS (Netherlands)

    Custers, J.B.M.

    1986-01-01

    Adventitious shoot formation implies the regeneration or development of shoots from fully differentiated tissue. Its application has, after the rise of in vitro culture, assumed large proportions. Then the question arose whether in vivo adventitious shoot formation could not be applied more widely i

  2. Rooting of microcuttings: Theory and practice

    NARCIS (Netherlands)

    Klerk, de G.J.M.

    2002-01-01

    Poor adventitious root formation is a major obstacle in micropropagation and in conventional propagation. This paper reviews recent progress in the understanding of adventitious root formation as a developmental process focusing on the role of plant hormones and on the effect of rooting conditions o

  3. Advances in experimental methods for root system architecture and root development

    Institute of Scientific and Technical Information of China (English)

    Jun-bang Wang; Xiu-juan Zhang; Chu Wu

    2015-01-01

    Plant roots play important roles in acquisition of water and nutrients, storage, anchoring, transport, and symbiosis with soil microorganisms, thus quantitative researches on root developmental processes are essential to understand root functions and root turnover in ecosystems, and at the same time such researches are the most difficult because roots are hidden underground. Therefore, how to investigate efficiently root functions and root dynamics is the core aspect in underground ecology. In this article, we reviewed some experimental methods used in root resear-ches on root development and root system architecture, and summarized the advantages and shortages of these meth-ods. Based on the analyses, we proposed three new ways to more understand root processes: (1) new experimental materials for root development; (2) a new observatory system comprised of multiple components, including many observatory windows installed in field, analysis software, and automatic data transport devices; (3) new techniques used to analyze quantitatively functional roots.

  4. Development of Machine Learning Tools in ROOT

    Science.gov (United States)

    Gleyzer, S. V.; Moneta, L.; Zapata, Omar A.

    2016-10-01

    ROOT is a framework for large-scale data analysis that provides basic and advanced statistical methods used by the LHC experiments. These include machine learning algorithms from the ROOT-integrated Toolkit for Multivariate Analysis (TMVA). We present several recent developments in TMVA, including a new modular design, new algorithms for variable importance and cross-validation, interfaces to other machine-learning software packages and integration of TMVA with Jupyter, making it accessible with a browser.

  5. Hormone symphony during root growth and development.

    Science.gov (United States)

    Garay-Arroyo, Adriana; De La Paz Sánchez, María; García-Ponce, Berenice; Azpeitia, Eugenio; Alvarez-Buylla, Elena R

    2012-12-01

    Hormones regulate plant growth and development in response to external environmental stimuli via complex signal transduction pathways, which in turn form complex networks of interaction. Several classes of hormones have been reported, and their activity depends on their biosynthesis, transport, conjugation, accumulation in the vacuole, and degradation. However, the activity of a given hormone is also dependent on its interaction with other hormones. Indeed, there is a complex crosstalk between hormones that regulates their biosynthesis, transport, and/or signaling functionality, although some hormones have overlapping or opposite functions. The plant root is a particularly useful system in which to study the complex role of plant hormones in the plastic control of plant development. Physiological, cellular, and molecular genetic approaches have been used to study the role of plant hormones in root meristem homeostasis. In this review, we discuss recent findings on the synthesis, signaling, transport of hormones and role during root development and examine the role of hormone crosstalk in maintaining homeostasis in the apical root meristem.

  6. Inhibition of auxin movement from the shoot into the root inhibits lateral root development in Arabidopsis

    Science.gov (United States)

    Reed, R. C.; Brady, S. R.; Muday, G. K.

    1998-01-01

    In roots two distinct polar movements of auxin have been reported that may control different developmental and growth events. To test the hypothesis that auxin derived from the shoot and transported toward the root controls lateral root development, the two polarities of auxin transport were uncoupled in Arabidopsis. Local application of the auxin-transport inhibitor naphthylphthalamic acid (NPA) at the root-shoot junction decreased the number and density of lateral roots and reduced the free indoleacetic acid (IAA) levels in the root and [3H]IAA transport into the root. Application of NPA to the basal half of or at several positions along the root only reduced lateral root density in regions that were in contact with NPA or in regions apical to the site of application. Lateral root development was restored by application of IAA apical to NPA application. Lateral root development in Arabidopsis roots was also inhibited by excision of the shoot or dark growth and this inhibition was reversible by IAA. Together, these results are consistent with auxin transport from the shoot into the root controlling lateral root development.

  7. [Effects nutrients on the seedlings root hair development and root growth of Poncirus trifoliata under hydroponics condition].

    Science.gov (United States)

    Cao, Xiu; Xia, Ren-Xue; Zhang, De-Jian; Shu, Bo

    2013-06-01

    Ahydroponics experiment was conducted to study the effects of nutrients (N, P, K, Ca, Mg, Fe, and Mn) deficiency on the length of primary root, the number of lateral roots, and the root hair density, length, and diameter on the primary root and lateral roots of Poncirus trifoliata seedlings. Under the deficiency of each test nutrient, root hair could generate, but was mainly concentrated on the root base and fewer on the root tip. The root hair density on lateral roots was significantly larger than that on primary root, but the root hair length was in adverse. The deficiency of each test nutrient had greater effects on the growth and development of root hairs, with the root hair density on primary root varied from 55.0 to 174.3 mm(-2). As compared with the control, Ca deficiency induced the significant increase of root hair density and length on primary root, P deficiency promoted the root hair density and length on the base and middle part of primary root and on the lateral roots significantly, Fe deficiency increased the root hair density but decreased the root hair length on the tip of primary root significantly, K deficiency significantly decreased the root hair density, length, and diameter on primary root and lateral roots, whereas Mg deficiency increased the root hair length of primary root significantly. In all treatments of nutrient deficiency, the primary root had the similar growth rate, but, with the exceptions of N and Mg deficiency, the lateral roots exhibited shedding and regeneration.

  8. Melatonin promotes adventitious root regeneration in in vitro shoot tip explants of the commercial sweet cherry rootstocks CAB-6P (Prunus cerasus L.), Gisela 6 (P. cerasus × P. canescens), and MxM 60 (P. avium × P. mahaleb).

    Science.gov (United States)

    Sarropoulou, Virginia N; Therios, Ioannis N; Dimassi-Theriou, Kortessa N

    2012-01-01

    The objectives of this study were to test the effects of melatonin (N-acetyl-5-methoxytryptamine), a natural compound of edible plants on the rooting of certain commercial sweet cherry rootstocks. Shoot tip explants from previous in vitro cultures of the cherry rootstocks CAB-6P (Prunus cerasus L.), Gisela 6 (P. cerasus × P. canescens), and M × M 60 (P. avium × P. mahaleb) were included in the experiment. The effect of indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) alone or in combination with melatonin was tested concerning their rooting potential. Seven concentrations of melatonin (0, 0.05, 0.1, 0.5, 1, 5, and 10 μM) alone or in combination with 5.71 μM of IAA or 4.92 μM of IBA were tested. For each rootstock, 21 treatments were included. The explants were grown in glass tubes containing 10 mL of substrate. The parameters measured include rooting percentage, number of roots per rooted explant, root length, and callus formation. The data presented in this study show that melatonin has a rooting promoting effect at a low concentration but a growth inhibitory effect at high concentrations. In the absence of auxin, 1 μM melatonin had auxinic response concerning the number and length of roots, but 10 μM melatonin was inhibitory to rooting in all the tested rootstocks. The final conclusion of this experiment is that exogenously applied melatonin acted as a rooting promoter and its action was similar to that of IAA.

  9. The Root Cap Determines Ethylene-Dependent Growth and Development in Maize Roots

    Institute of Scientific and Technical Information of China (English)

    Achim Hahn; Roman Zimmermann; Dierk Wanke; Klaus Harter; Hans G.Edelmann

    2008-01-01

    Besides providing protection against mechanical damage to the root tip,the root cap is involved in the perception and processing of diverse external and internal stimuli resulting in altered growth and development.The transduction of these stimuli includes hormonal signaling pathways such as those of auxin,ethylene and cytokinin.Here,we show that the root cap is essential for the ethylene-induced regulation of elongation growth and root hair formation in maize.Exogenously applied ethylene is no longer able to inhibit elongation growth when the root cap has been surgically removed prior to hormone treatment.Reconstitution of the cap positively correlates with the developing capacity of the roots to respond to ethylene again.In contrast,the removal of the root cap does not per se affect growth inhibition controlled by auxin and cytokinin.Furthermore,our semi-quantitative RT-PCR results support earlier findings that the maize root cap is a site of high gene expression activity with respect to sensing and responding to hormones such as ethylene.From these data,we propose a novel function of the root cap which is the establishment of competence to respond to ethylene in the distal zones of the root.

  10. A histochemical study of root nodule development.

    NARCIS (Netherlands)

    Wiel, van de C.C.M.

    1991-01-01

    In cooperation with soil bacteria of the genera Rhizobium , Bradyrhizobium or Azorhizobium , many members of the legume family are able to form specialized organs on their roots, called root nodules. The bacteria, wrapped up inside a plant membrane, are accomodated in large parenchymatic cells locat

  11. Phaseolus vulgaris RbohB functions in lateral root development

    Science.gov (United States)

    Montiel, Jesús; Arthikala, Manoj-Kumar; Quinto, Carmen

    2013-01-01

    Respiratory burst oxidase homologs (RBOHs) catalyze the reduction of oxygen to generate superoxide anion, a kind of reactive oxygen species (ROS). The ROS produced by RBOHs play essential roles in diverse processes, such as root hair development, stomata closure and signaling mechanisms in response to abiotic stimuli and during plant-pathogen interactions. Recently, we found that PvRbohB silencing in transgenic Phaseolus vulgaris roots had a negative impact on lateral root density. In this work, we show that the downregulation of PvRbohB affects both the growth and ROS levels in recently emerged lateral roots. In addition, we found that the PvRbohB promoter was activated during lateral root primordium initiation in the pericycle, and remained active throughout lateral root development. This study identifies RBOHs as potentially important players in lateral root development in P. vulgaris. PMID:23221754

  12. Evolution of Root Characters of Soybean Varieties Developed in Different Years

    Institute of Scientific and Technical Information of China (English)

    YANG Xiu-hong; WU Zong-pu; ZHANG Guo-dong

    2002-01-01

    It was studied that the evolution of root characteristics among 42 soybean varieties developed in Heilongjiang and Jilin Province in different years. The results showed that there were differences on the root characteristics among soybean varieties. From 1950s to 1990s, root fresh weight, root volume, root surface, root dry weight, lateral root length of main root characters tendedly increased with the variable development years. The root system of the varieties in 1990s was relatively well developed compared with that in the other years. The evolutionary trend of the root system of soybean varieties was increasing in root weight, root volume, root surface and length of lateral root.

  13. Deciphering Phosphate Deficiency-Mediated Temporal Effects on Different Root Traits in Rice Grown in a Modified Hydroponic System.

    Science.gov (United States)

    Negi, Manisha; Sanagala, Raghavendrarao; Rai, Vandna; Jain, Ajay

    2016-01-01

    Phosphate (Pi), an essential macronutrient for growth and development of plant, is often limiting in soils. Plants have evolved an array of adaptive strategies including modulation of root system architecture (RSA) for optimal acquisition of Pi. In rice, a major staple food, RSA is complex and comprises embryonically developed primary and seminal roots and post-embryonically developed adventitious and lateral roots. Earlier studies have used variant hydroponic systems for documenting the effects of Pi deficiency largely on primary root growth. Here, we report the temporal effects of Pi deficiency in rice genotype MI48 on 15 ontogenetically distinct root traits by using easy-to-assemble and economically viable modified hydroponic system. Effects of Pi deprivation became evident after 4 days- and 7 days-treatments on two and eight different root traits, respectively. The effects of Pi deprivation for 7 days were also evident on different root traits of rice genotype Nagina 22 (N22). There were genotypic differences in the responses of primary root growth along with lateral roots on it and the number and length of seminal and adventitious roots. Notably though, there were attenuating effects of Pi deficiency on the lateral roots on seminal and adventitious roots and total root length in both these genotypes. The study thus revealed both differential and comparable effects of Pi deficiency on different root traits in these genotypes. Pi deficiency also triggered reduction in Pi content and induction of several Pi starvation-responsive (PSR) genes in roots of MI48. Together, the analyses validated the fidelity of this modified hydroponic system for documenting Pi deficiency-mediated effects not only on different traits of RSA but also on physiological and molecular responses.

  14. Deciphering Phosphate Deficiency-Mediated Temporal Effects on Different Root Traits in Rice Grown in a Modified Hydroponic System

    Science.gov (United States)

    Negi, Manisha; Sanagala, Raghavendrarao; Rai, Vandna; Jain, Ajay

    2016-01-01

    Phosphate (Pi), an essential macronutrient for growth and development of plant, is often limiting in soils. Plants have evolved an array of adaptive strategies including modulation of root system architecture (RSA) for optimal acquisition of Pi. In rice, a major staple food, RSA is complex and comprises embryonically developed primary and seminal roots and post-embryonically developed adventitious and lateral roots. Earlier studies have used variant hydroponic systems for documenting the effects of Pi deficiency largely on primary root growth. Here, we report the temporal effects of Pi deficiency in rice genotype MI48 on 15 ontogenetically distinct root traits by using easy-to-assemble and economically viable modified hydroponic system. Effects of Pi deprivation became evident after 4 days- and 7 days-treatments on two and eight different root traits, respectively. The effects of Pi deprivation for 7 days were also evident on different root traits of rice genotype Nagina 22 (N22). There were genotypic differences in the responses of primary root growth along with lateral roots on it and the number and length of seminal and adventitious roots. Notably though, there were attenuating effects of Pi deficiency on the lateral roots on seminal and adventitious roots and total root length in both these genotypes. The study thus revealed both differential and comparable effects of Pi deficiency on different root traits in these genotypes. Pi deficiency also triggered reduction in Pi content and induction of several Pi starvation-responsive (PSR) genes in roots of MI48. Together, the analyses validated the fidelity of this modified hydroponic system for documenting Pi deficiency-mediated effects not only on different traits of RSA but also on physiological and molecular responses. PMID:27200025

  15. Development of TRatioPlot in ROOT

    CERN Document Server

    Gessinger-Befurt, Paul

    2016-01-01

    The ROOT data analysis and visualization framework is a software package which is widely used in physics, especially in high energy physics. A common visualization which has so far been lacking a direct implementation is the ratio plot, as well as a few similar types of plots. The scope and goal of the summer student project at CERN was to implement a class in ROOT itself, that can take care of the most common types of calculations, and produces high quality visuals.

  16. Relationship between Indole-3-Acetic Acid Levels in Apple (Malus pumila Mill) Rootstocks Cultured in Vitro and Adventitious Root Formation in the Presence of Indole-3-Butyric Acid 1

    Science.gov (United States)

    Alvarez, Rafael; Nissen, Scott J.; Sutter, Ellen G.

    1989-01-01

    In vitro rooting response and indole-3-acetic acid (IAA) levels were examined in two genetically related dwarfing apple (Malus pumila Mill) rootstocks. M.26 and M.9 were cultured in vitro using Linsmaier-Skoog medium supplemented with benzyladenine (BA), indole-3-butyric acid (IBA), and 1,3,5-trihydroxybenzoic acid (PG). Rooting response was tested in Lepoivre medium supplemented with IBA and PG. IBA concentrations of 12.0 and 4.0 micromolar induced the maximum rooting percentages for M.9 and M.26, respectively. At these concentrations rooting response was 100% for M.26 and 80% for M.9. Free and conjugated IAA levels were determined in M.26 and M.9 shoots prior to root inducing treatment by high performance liquid chromatography with fluorescence detection and validated by gas chromatography-mass spectrometry using 13[C6]IAA as internal standard. Basal sections of M.26 shoots contained 2.8 times more free IAA than similar tissue in M.9 (477.1 ± 6.5 versus 166.6 ± 6.7 nanograms per gram fresh weight), while free IAA levels in apical sections of M.26 and M.9 shoots were comparable (298.0 ± 4.4 versus 263.7 ± 9.3 nanograms per gram fresh weight). Conjugated IAA levels were significantly higher in M.9 than in M.26 indicating that a greater proportion of total IAA was present as a conjugate in M.9. These data suggest that differences between M.26 and M.9 rooting responses may be related to differences in free IAA levels in the shoot base. PMID:16666562

  17. Adventitious rhizogenesis in Bambusa nutans and Bambusa tulda: Influence of seasonal variation, IBA and cutting type

    Institute of Scientific and Technical Information of China (English)

    S. Singh; S. Yadav; P. K. Patel; S.A.Ansari

    2011-01-01

    The influence of seasonal variation,indole-3-butyric acid (IBA) and type of cuttings wasexamined on induction and growth of adventitious roots in Bambusa nutans Wall.and Bambusa tulda Roxb.Singlenode culm and culm-branch cuttings from the mature culms were provided with immersion treatment for 24 h of either water (control) or 2 mM IBA in four different seasons,i.e.,spring (mid February),summer (mid May),rainy (mid July),and winter (mid November) and maintained for two months in the mist chamber at the relative humidity of (70±5)%and the temperature of (30±2)℃.In B.nutans,adventitious rooting occuffed in both types of cuttings in all the seasons with the best rooting in the summer season i.e.,May (88% in culm cuttings) and the least in winter.On the contrary,adventitious rooting was recorded only in culm cuttings in spring and summer season in B.tulda.IBA treatment significantly enhanced rooting,root number and root length; registering 14 to 17 times improvement over control in the best rooting season.Three factor- interactions (season × cutting type × IBA treatment) were significant for rooting in B.nutans and all characteristics,except sprouting in B.tulda.Thus,single-node culm and culm-branch cuttings in B.nutans and culm cuttings in B.tulda treated with 2 mM IBA during spring (February)to summer (May) season are recommended for their clonal multiplication.

  18. 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.

  19. Lateral root development in Arabidopsis: fifty shades of auxin.

    Science.gov (United States)

    Lavenus, Julien; Goh, Tatsuaki; Roberts, Ianto; Guyomarc'h, Soazig; Lucas, Mikaël; De Smet, Ive; Fukaki, Hidehiro; Beeckman, Tom; Bennett, Malcolm; Laplaze, Laurent

    2013-08-01

    The developmental plasticity of the root system represents a key adaptive trait enabling plants to cope with abiotic stresses such as drought and is therefore important in the current context of global changes. Root branching through lateral root formation is an important component of the adaptability of the root system to its environment. Our understanding of the mechanisms controlling lateral root development has progressed tremendously in recent years through research in the model plant Arabidopsis thaliana (Arabidopsis). These studies have revealed that the phytohormone auxin acts as a common integrator to many endogenous and environmental signals regulating lateral root formation. Here, we review what has been learnt about the myriad roles of auxin during lateral root formation in Arabidopsis.

  20. Conserved Gene Expression Programs in Developing Roots from Diverse Plants.

    Science.gov (United States)

    Huang, Ling; Schiefelbein, John

    2015-08-01

    The molecular basis for the origin and diversification of morphological adaptations is a central issue in evolutionary developmental biology. Here, we defined temporal transcript accumulation in developing roots from seven vascular plants, permitting a genome-wide comparative analysis of the molecular programs used by a single organ across diverse species. The resulting gene expression maps uncover significant similarity in the genes employed in roots and their developmental expression profiles. The detailed analysis of a subset of 133 genes known to be associated with root development in Arabidopsis thaliana indicates that most of these are used in all plant species. Strikingly, this was also true for root development in a lycophyte (Selaginella moellendorffii), which forms morphologically different roots and is thought to have evolved roots independently. Thus, despite vast differences in size and anatomy of roots from diverse plants, the basic molecular mechanisms employed during root formation appear to be conserved. This suggests that roots evolved in the two major vascular plant lineages either by parallel recruitment of largely the same developmental program or by elaboration of an existing root program in the common ancestor of vascular plants.

  1. Quantification of Adventitial Vasa Vasorum Vascularization in Double-injury Restenotic Arteries

    Institute of Scientific and Technical Information of China (English)

    Meng Ye; Bai-Gen Zhang; Lan Zhang; Hui Xie; Hao Zhang

    2015-01-01

    Background:Accumulating evidence indicates a potential role of adventitial vasa vasorum (VV) dysfunction in the pathophysiology of restenosis.However,characterization ofVV vascularization in restenotic arteries with primary lesions is still missing.In this study,we quantitatively evaluated the response of adventitial VV to vascular injury resulting from balloon angioplasty in diseased arteries.Methods:Primary atherosclerotic-like lesions were induced by the placement of an absorbable thread surrounding the carotid artery of New Zealand rabbits.Four weeks following double-injury induced that was induced by secondary balloon dilation,three-dimensional patterns of adventitial VV were reconstructed;the number,density,and endothelial surface of VV were quantified using micro-computed tomography.Histology and immunohistochemistry were performed in order to examine the development of intimal hyperplasia.Results:Results from our study suggest that double injured arteries have a greater number of VV,increased luminal surface,and an elevation in the intima/media ratio (I/M),along with an accumulation ofmacrophages and smooth muscle cells in the intima,as compared to sham or single injury arteries.I/M and the number of VV were positively correlated (R2 =0.82,P < 0.001).Conclusions:Extensive adventitial VV neovascularization occurs in injured arteries after balloon angioplasty,which is associated with intimal hyperplasia.Quantitative assessment of adventitial VV response may provide insight into the basic biological process of postangioplasty restenosis.

  2. Integration of root phenes for soil resource acquisition

    Directory of Open Access Journals (Sweden)

    Larry Matthew York

    2013-09-01

    Full Text Available Suboptimal availability of water and nutrients is a primary limitation to plant growth in terrestrial ecosystems. The acquisition of soil resources by plant roots is therefore an important component of plant fitness and agricultural productivity. Plant root systems comprise a set of phenes, or traits, that interact. Phenes are the units of the plant phenotype, and phene states represent the variation in form and function a particular phene may take. Root phenes can be classified as affecting resource acquisition or utilization, influencing acquisition through exploration or exploitation, and in being metabolically influential or neutral. These classifications determine how one phene will interact with another phene, whether through foraging mechanisms or metabolic economics. Phenes that influence one another through foraging mechanisms are likely to operate within a phene module, a group of interacting phenes, that may be co-selected. Examples of root phene interactions discussed are: 1 root hair length × root hair density, 2 lateral branching × root cortical aerenchyma, 3 adventitious root number × adventitious root respiration and basal root growth angle, 4 nodal root number × root cortical aerenchyma, and 5 basal root growth angle × root hair length and density. Progress in the study of phenes and phene interactions will be facilitated by employing simulation modeling and near-isophenic lines that allow the study of specific phenes and phene combinations within a common phenotypic background. Developing a robust understanding of the phenome at the organismal level will require new lines of inquiry into how phenotypic integration influences plant function in diverse environments. A better understanding of how root phenes interact to affect soil resource acquisition will be an important tool in the breeding of crops with superior stress tolerance and reduced dependence on intensive use of inputs.

  3. The effect of root preparation technique and instrumentation length on the development of apical root cracks.

    Science.gov (United States)

    Adorno, Carlos G; Yoshioka, Takatomo; Suda, Hideaki

    2009-03-01

    The purpose of this study was to compare the effects of root canal preparation techniques and instrumentation length on the development of apical root cracks. Forty extracted mandibular premolars with straight roots were randomly selected and mounted on resin blocks with simulated periodontal ligaments, and the apex was exposed. The teeth were divided into four groups of 10 teeth each for different canal preparation techniques and instrumentation lengths: group A: step-back preparation (SB) with stainless steel files (SF) using root canal length (RCL) to guide instrumentation length; group B: SB using RCL - 1 mm; group C: crown-down preparation (CD) with Profile using RCL; and group D: CD with PF using RCL - 1 mm. Digital images of the instrumentation sequence were compared for each tooth. Statistical analysis revealed a significant effect of instrumentation length (p 0.05) on the development of apical cracks.

  4. Growth and development of the root apical meristem.

    Science.gov (United States)

    Perilli, Serena; Di Mambro, Riccardo; Sabatini, Sabrina

    2012-02-01

    A key question in plant developmental biology is how cell division and cell differentiation are balanced to modulate organ growth and shape organ size. In recent years, several advances have been made in understanding how this balance is achieved during root development. In the Arabidopsis root meristem, stem cells in the apical region of the meristem self-renew and produce daughter cells that differentiate in the distal meristem transition zone. Several factors have been implicated in controlling the different functional zones of the root meristem to modulate root growth; among these, plant hormones have been shown to play a main role. In this review, we summarize recent findings regarding the role of hormone signaling and transcriptional networks in regulating root development.

  5. 大叶黄杨无芽茎段不定芽再生及其起源%Regenerating and Origin of Adventitious Shoots from Inter-Node Explants of Euonymus japonicus in vitro

    Institute of Scientific and Technical Information of China (English)

    王茂良; 任桂芳; 王建红; 冯慧; 赵梁军

    2005-01-01

    In order to improve the resistance of Euonymus japonicus, its ability of adventitious shoots regenerating from internode stem-segment were researched on MS medium in vitro. The effect of both plant growth regulators and carbon resources in media on adventitious shoots differentiating was studied. Regenerating system of E. japonicus was established successfully.Adventitious shoots were highly obtained from inter-node explants inoculated on MS media supplemented with 6-BA 1.7 mg·L-1+ IBA 0.005 mg·L-1 or 6-BA 1.9 mg·L-1 + IBA 0.03 mg·L-1. The regenerating ratio reached to 52.4% and 46.7% respectively. Media for inducing adventitious roots were I/2MS + IAA 0.5 mg·L-1. Adventitious shoots originated from surface tissue of inter-node stem-segment.

  6. Identification of a novel mitochondrial protein, short postembryonic roots 1 (SPR1), involved in root development and iron homeostasis in Oryza sativa.

    Science.gov (United States)

    Jia, Liqiang; Wu, Zhongchang; Hao, Xi; Carrie, Chris; Zheng, Libin; Whelan, James; Wu, Yunrong; Wang, Shoufeng; Wu, Ping; Mao, Chuanzao

    2011-02-01

    • A rice mutant, Oryza sativa short postembryonic roots 1 (Osspr1), has been characterized. It has short postembryonic roots, including adventitious and lateral roots, and a lower iron content in its leaves. • OsSPR1 was identified by map-based cloning. It encodes a novel mitochondrial protein with the Armadillo-like repeat domain. • Osspr1 mutants exhibited decreased root cell elongation. The iron content of the mutant shoots was significantly altered compared with that of wild-type shoots. A similar pattern of alteration of manganese and zinc concentrations in shoots was also observed. Complementation of the mutant confirmed that OsSPR1 is involved in post-embryonic root elongation and iron homeostasis in rice. OsSPR1 was found to be ubiquitously expressed in various tissues throughout the plant. The transcript abundance of various genes involved in iron uptake and signaling via both strategies I and II was similar in roots of wild-type and mutant plants, but was higher in the leaves of mutant plants. • Thus, a novel mitochondrial protein that is involved in root elongation and plays a role in metal ion homeostasis has been identified.

  7. Response to Bagavathiannan and Van Acker's "Transgenes and national boundaries - The need for international regulations": Biotechnology developers and regulators already consider transgene movement across national boundaries and the environmental risks posed by adventitious presence of unapproved events are overstated.

    Science.gov (United States)

    Nickson, Thomas E; Raybould, Alan F

    2009-01-01

    Bagavathiannan and Van Acker propose greater international cooperation and information sharing in risk assessment for biotechnology-derived crops because pollen- and seed-mediated gene flow across political boundaries may lead to the adventitious presence of unapproved transgenes at sites along the borders of neighboring countries. However, they fail to convince us that something is wrong with the current situation and provide no details of how it could be improved.

  8. Modeling gene flow distribution within conventional fields and development of a simplified sampling method to quantify adventitious GM contents in maize

    OpenAIRE

    2015-01-01

    Cationic a-helical antimicrobial peptides such as BP100 are of increasing interest for developing novel phytosanitary or therapeutic agents and products with industrial applications. Biotechnological production of these peptides in plants can be severely impaired due to the toxicity exerted on the host by high-level expression. This can be overcome by using inducible promoters with extremely low activity throughout plant development, although the yields are limited. We examined the use of mod...

  9. Regulation of Shoot and Root Development through Mutual Signaling

    Institute of Scientific and Technical Information of China (English)

    Jér(o)me Puig; Germain Pauluzzi; Emmanuel Guiderdoni; Pascal Gantet

    2012-01-01

    Plants adjust their development in relation to the availability of nutrient sources.This necessitates signaling between root and shoot.Aside from the well-known systemic signaling processes mediated by auxin,cytokinin,and sugars,new pathways involving carotenoid-derived hormones have recently been identified.The auxin-responsive MAX pathway controls shoot branching through the biosynthesis of strigolactone in the roots.The BYPASS1 gene affects the production of an as-yet unknown carotenoid-derived substance in roots that promotes shoot development.Novel local and systemic mechanisms that control adaptive root development in response to nitrogen and phosphorus starvation were recently discovered.Notably,the ability of the NITRATE TRANSPORTER 1.1 to transport auxin drew for the first time a functional link between auxin,root development,and nitrate availability in soil.The study of plant response to phosphorus starvation allowed the identification of a systemic mobile miRNA.Deciphering and integrating these signaling pathways at the whole-plant level provide a new perspective for understanding how plants regulate their development in response to environmental cues.

  10. Cell Wall Heterogeneity in Root Development of Arabidopsis

    Science.gov (United States)

    Somssich, Marc; Khan, Ghazanfar Abbas; Persson, Staffan

    2016-01-01

    Plant cell walls provide stability and protection to plant cells. During growth and development the composition of cell walls changes, but provides enough strength to withstand the turgor of the cells. Hence, cell walls are highly flexible and diverse in nature. These characteristics are important during root growth, as plant roots consist of radial patterns of cells that have diverse functions and that are at different developmental stages along the growth axis. Young stem cell daughters undergo a series of rapid cell divisions, during which new cell walls are formed that are highly dynamic, and that support rapid anisotropic cell expansion. Once the cells have differentiated, the walls of specific cell types need to comply with and support different cell functions. For example, a newly formed root hair needs to be able to break through the surrounding soil, while endodermal cells modify their walls at distinct positions to form Casparian strips between them. Hence, the cell walls are modified and rebuilt while cells transit through different developmental stages. In addition, the cell walls of roots readjust to their environment to support growth and to maximize nutrient uptake. Many of these modifications are likely driven by different developmental and stress signaling pathways. However, our understanding of how such pathways affect cell wall modifications and what enzymes are involved remain largely unknown. In this review we aim to compile data linking cell wall content and re-modeling to developmental stages of root cells, and dissect how root cell walls respond to certain environmental changes. PMID:27582757

  11. [Normal and Adventitious Breath Sounds].

    Science.gov (United States)

    Koehler, U; Hildebrandt, O; Kerzel, S; Urban, C; Hoehle, L; Weissflog, A; Nikolaizik, W; Koehler, J; Sohrabi, K; Gross, V

    2016-06-01

    Auscultation of the lung is an inexpensive, noninvasive and easy-to-perform tool. It is an important part of the physical examination and is help ful to distinguish physiological respiratory sounds from pathophysiological events. Computerized lung sound analysis is a powerful tool for optimizing and quantifying electronic auscultation based on the specific lung sound spectral characteristics. The automatic analysis of respiratory sounds assumes that physiological and pathological sounds are reliably analyzed based on special algorithms. The development of automated long-term lungsound monitors enables objective assessment of different respiratory symptoms.

  12. Theoretical versus Grass-Roots Development of a Community Partnership

    Science.gov (United States)

    Escandon, Socorro

    2010-01-01

    The purpose of this qualitative study was to examine Bracht, Kingbury, and Rissel's five-stage community development model as applied to a grass-roots community action group. The sample consisted of low-income, predominantly Hispanic women in a community action group in a Southwestern barrio, some of whom were experiencing domestic violence. The…

  13. Nodulin gene expression in the developing pea root nodule.

    NARCIS (Netherlands)

    Govers, F.

    1987-01-01

    Infection of leguminous plants with bacteria of the genus Rhizobium results in a symbiotic interaction which brings about the development of an entirely new organ on the plant, the root nodule. Within this organ about half of the plant cells are inhabited by bacteroids, the endosymblotic form

  14. Adventitious Reinforcement of Maladaptive Stimulus Control Interferes with Learning.

    Science.gov (United States)

    Saunders, Kathryn J; Hine, Kathleen; Hayashi, Yusuke; Williams, Dean C

    2016-09-01

    Persistent error patterns sometimes develop when teaching new discriminations. These patterns can be adventitiously reinforced, especially during long periods of chance-level responding (including baseline). Such behaviors can interfere with learning a new discrimination. They can also disrupt already learned discriminations, if they re-emerge during teaching procedures that generate errors. We present an example of this process. Our goal was to teach a boy with intellectual disabilities to touch one of two shapes on a computer screen (in technical terms, a simple simultaneous discrimination). We used a size-fading procedure. The correct stimulus was at full size, and the incorrect-stimulus size increased in increments of 10 %. Performance was nearly error free up to and including 60 % of full size. In a probe session with the incorrect stimulus at full size, however, accuracy plummeted. Also, a pattern of switching between choices, which apparently had been established in classroom instruction, re-emerged. The switching pattern interfered with already-learned discriminations. Despite having previously mastered a fading step with the incorrect stimulus up to 60 %, we were unable to maintain consistently high accuracy beyond 20 % of full size. We refined the teaching program such that fading was done in smaller steps (5 %), and decisions to "step back" to a smaller incorrect stimulus were made after every 5-instead of 20-trials. Errors were rare, switching behavior stopped, and he mastered the discrimination. This is a practical example of the importance of designing instruction that prevents adventitious reinforcement of maladaptive discriminated response patterns by reducing errors during acquisition.

  15. Root exudation and root development of lettuce (Lactuca sativa L. cv. Tizian) as affected by different soils.

    Science.gov (United States)

    Neumann, G; Bott, S; Ohler, M A; Mock, H-P; Lippmann, R; Grosch, R; Smalla, K

    2014-01-01

    Development and activity of plant roots exhibit high adaptive variability. Although it is well-documented, that physicochemical soil properties can strongly influence root morphology and root exudation, particularly under field conditions, a comparative assessment is complicated by the impact of additional factors, such as climate and cropping history. To overcome these limitations, in this study, field soils originating from an unique experimental plot system with three different soil types, which were stored at the same field site for 10 years and exposed to the same agricultural management practice, were used for an investigation on effects of soil type on root development and root exudation. Lettuce (Lactuca sativa L. cv. Tizian) was grown as a model plant under controlled environmental conditions in a minirhizotrone system equipped with root observation windows (rhizoboxes). Root exudates were collected by placing sorption filters onto the root surface followed by subsequent extraction and GC-MS profiling of the trapped compounds. Surprisingly, even in absence of external stress factors with known impact on root exudation, such as pH extremes, water and nutrient limitations/toxicities or soil structure effects (use of sieved soils), root growth characteristics (root length, fine root development) as well as profiles of root exudates were strongly influenced by the soil type used for plant cultivation. The results coincided well with differences in rhizosphere bacterial communities, detected in field-grown lettuce plants cultivated on the same soils (Schreiter et al., this issue). The findings suggest that the observed differences may be the result of plant interactions with the soil-specific microbiomes.

  16. Root exudation and root development of lettuce (Lactuca sativa L.cv. Tizian as affected by different soils

    Directory of Open Access Journals (Sweden)

    Günter eNeumann

    2014-01-01

    Full Text Available Development and activity of plant roots exhibits high adaptive variability. Although it is well-documented, that physicochemical soil properties can strongly influence root morphology and root exudation, particularly under field conditions, a comparative assessment is complicated by the impact of additional factors, such as climate and cropping history. To overcome these limitations, in this study, field soils originating from an unique experimental plot system with three different soil types, which were stored at the same field site for ten years and exposed to the same agricultural management practice, were used for an investigation on effects of soil type on root development and root exudation. Lettuce (Lactuca sativa L. cv. Tizian was used as a model plant, grown under controlled environmental conditions in a minirhizotrone system equipped with root observation windows (rhizoboxes. Root exudates were collected by placing sorption filters onto the root surface followed by subsequent extraction and GC-MS profiling of the trapped compounds. Surprisingly, even in absence of external stress factors with known impact on root exudation, such as pH extremes, water and nutrient limitations/toxicities or soil structure effects (use of sieved soils, root growth characteristics (root length, fine root development as well as profiles of root exudates were strongly influenced by the soil type used for plant cultivation. The results coincided well with differences in rhizosphere bacterial communities, detected in field-grown lettuce plants cultivated on the same soils (Schreiter et al., this issue. The findings suggest that the observed differences may be the result of plant interactions with the soil-specific microbiomes.

  17. Adventitial cystic disease of the axillary artery.

    Science.gov (United States)

    Elster, Eric A; Hewlett, Stanley; DeRienzo, Damian P; Donovan, Sean; Georgia, Jeff; Yavorski, Chester C

    2002-01-01

    Adventitial cystic disease (ACD) is an extremely rare cause of arterial and venous insufficiency, with only 317 reported cases in the world literature. These lesions have been previously described in the popliteal fossa, external iliac artery, and distal brachial, radial, and ulnar arteries as well as in the proximal saphenous vein at the ankle. We describe here the first reported case of this disease in a proximal vessel, the axillary artery. A 33-year-old man was evaluated for upper extremity arterial insufficiency and was diagnosed with ACD on the basis of physical examination and radiographic findings, which was confirmed by pathological assessment. The patient was treated by excision of the lesion and interposition vein bypass. As this represents the first case of ACD in the proximal vasculature, it demonstrates that these lesions can occur in axial blood vessels.

  18. Is Trust the Missing Root of Institutions, Education, and Development?

    DEFF Research Database (Denmark)

    Bjørnskov, Christian; Méon, Pierre-Guillaume

    2013-01-01

    We report evidence that trust is the missing root relating education, institutions, and economic development. We observe that more trust both increases education and improves legal and bureaucratic institutions, which in turn spurs economic development. We substantiate this intuition with a serie...... of regressions that provide evidence that trust determines both education and the quality of institutions, and that education and institutions in turn affect GDP per capita....

  19. Ubiquitin-related modifiers of Arabidopsis thaliana influence root development.

    Directory of Open Access Journals (Sweden)

    Florian John

    Full Text Available Ubiquitins are small peptides that allow for posttranslational modification of proteins. Ubiquitin-related modifier (URM proteins belong to the class of ubiquitin-like proteins. A primary function of URM proteins has been shown to be the sulfur transfer reaction leading to thiolation of tRNAs, a process that is important for accurate and effective protein translation. Recent analyses revealed that the Arabidopsis genome codes for two URM proteins, URM11 and URM12, which both are active in the tRNA thiolation process. Here, we show that URM11 and URM12 have overlapping expression patterns and are required for tRNA thiolation. The characterization of urm11 and urm12 mutants reveals that the lack of tRNA thiolation induces changes in general root architecture by influencing the rate of lateral root formation. In addition, they synergistically influence root hair cell growth. During the sulfur transfer reaction, URM proteins of different organisms interact with a thiouridylase, a protein-protein interaction that also takes place in Arabidopsis, since URM11 and URM12 interact with the Arabidopsis thiouridylase ROL5. Hence, the sulfur transfer reaction is conserved between distantly related species such as yeast, humans, and plants, and in Arabidopsis has an impact on root development.

  20. Adventitial vasa vasorum arteriosclerosis in abdominal aortic aneurysm.

    Directory of Open Access Journals (Sweden)

    Hiroki Tanaka

    Full Text Available Abdominal aortic aneurysm (AAA is a common disease among elderly individuals. However, the precise pathophysiology of AAA remains unknown. In AAA, an intraluminal thrombus prevents luminal perfusion of oxygen, allowing only the adventitial vaso vasorum (VV to deliver oxygen and nutrients to the aortic wall. In this study, we examined changes in the adventitial VV wall in AAA to clarify the histopathological mechanisms underlying AAA. We found marked intimal hyperplasia of the adventitial VV in the AAA sac; further, immunohistological studies revealed proliferation of smooth muscle cells, which caused luminal stenosis of the VV. We also found decreased HemeB signals in the aortic wall of the sac as compared with those in the aortic wall of the neck region in AAA. The stenosis of adventitial VV in the AAA sac and the malperfusion of the aortic wall observed in the present study are new aspects of AAA pathology that are expected to enhance our understanding of this disease.

  1. First permanent molar root development arrest associated with compound odontoma.

    Science.gov (United States)

    Gunda, Sachin A; Patil, Anil; Varekar, Aniruddha

    2013-07-04

    Trauma or infection to the primary tooth may have deleterious effects on the underlying developing tooth buds. Anatomically the root apices of primary teeth are in close proximity to the developing permanent tooth buds; hence spread of infection originating from pulp necrosis of primary tooth may not only affect the underlying tooth bud but may also affect the adjacent tooth buds. The extent of malformation depends on the developmental stage of tooth or the age of patient. Presented here is a rare case of complete arrest of maxillary first permanent molar root growth due to spread of periapical infection originating from second primary molar leading to failure of its eruption and finally extraction. Histopathlogical analysis revealed compound odontoma associated with maxillary first permanent molar.

  2. Arabidopsis: an adequate model for dicot root systems?

    OpenAIRE

    Zobel, Richard W.

    2016-01-01

    The Arabidopsis root system is frequently considered to have only three classes of root: primary, lateral, and adventitious. Research with other plant species has suggested up to 8 different developmental/functional classes of root for a given plant root system. If Arabidopsis has only three classes of root, it may not be an adequate model for eudicot plant root systems. Recent research, however, can be interpreted to suggest that pre-flowering Arabidopsis does have at least five (5) of th...

  3. Arabidopsis: An Adequate Model for Dicot Root Systems?

    OpenAIRE

    Zobel, Richard W.

    2016-01-01

    The Arabidopsis root system is frequently considered to have only three classes of root: primary, lateral, and adventitious. Research with other plant species has suggested up to eight different developmental/functional classes of root for a given plant root system. If Arabidopsis has only three classes of root, it may not be an adequate model for eudicot plant root systems. Recent research, however, can be interpreted to suggest that pre-flowering Arabidopsis does have at least five (5) of t...

  4. Transcription reprogramming during root nodule development in Medicago truncatula.

    Directory of Open Access Journals (Sweden)

    Sandra Moreau

    Full Text Available Many genes which are associated with root nodule development and activity in the model legume Medicago truncatula have been described. However information on precise stages of activation of these genes and their corresponding transcriptional regulators is often lacking. Whether these regulators are shared with other plant developmental programs also remains an open question. Here detailed microarray analyses have been used to study the transcriptome of root nodules induced by either wild type or mutant strains of Sinorhizobium meliloti. In this way we have defined eight major activation patterns in nodules and identified associated potential regulatory genes. We have shown that transcription reprogramming during consecutive stages of nodule differentiation occurs in four major phases, respectively associated with (i early signalling events and/or bacterial infection; plant cell differentiation that is either (ii independent or (iii dependent on bacteroid differentiation; (iv nitrogen fixation. Differential expression of several genes involved in cytokinin biosynthesis was observed in early symbiotic nodule zones, suggesting that cytokinin levels are actively controlled in this region. Taking advantage of databases recently developed for M. truncatula, we identified a small subset of gene expression regulators that were exclusively or predominantly expressed in nodules, whereas most other regulators were also activated under other conditions, and notably in response to abiotic or biotic stresses. We found evidence suggesting the activation of the jasmonate pathway in both wild type and mutant nodules, thus raising questions about the role of jasmonate during nodule development. Finally, quantitative RT-PCR was used to analyse the expression of a series of nodule regulator and marker genes at early symbiotic stages in roots and allowed us to distinguish several early stages of gene expression activation or repression.

  5. Potential Role of Axonal Chemorepellent Slit2 in Modulating Adventitial Inflammation in a Rat Carotid Artery Balloon Injury Model.

    Science.gov (United States)

    Liu, Dong; Xiao, Yan; Subramanian, Romesh R; Okamoto, Ei-Ichi; Wilcox, Josiah N; Anderson, Leonard; De Leon, Hector

    2016-05-01

    Leukocyte infiltration of adventitial and perivascular tissues is an early event in the development of vascular remodeling after injury. We investigated whether Slit/Robo-an axonal chemorepellent system in vertebrate and invertebrate development-is activated during the inflammatory phase that follows endothelial denudation. Using the rat carotid artery model of angioplasty, we conducted a time course analysis of mRNAs encoding Slit ligands (Slit2 and Slit3) and Robo receptors (Robo1, Robo2, and Robo4), as well as proinflammatory cell adhesion molecule (CAM) genes. Adventitial inflammatory cells were counted in immunostained arterial sections. E-selectin, vascular CAM-1, and intercellular CAM-1 were upregulated 2-3 hours after injury, followed by infiltration of neutrophils and monocytes as evidenced by real-time polymerase chain reaction, in situ hybridization, and immunohistochemistry. Slit2, Slit3, and Robo genes exhibited no expression changes at 3 hours; however, they were markedly upregulated 1 day after angioplasty. Intercellular CAM-1 expression was reduced by 50%, and the number of adventitial neutrophils decreased by >75% 1 day after angioplasty. Slit2 has been shown to be a potent chemorepelent of leukocytes, endothelial cells, and smooth muscle cells. Thus, we decided to further investigate the localization of Slit2 in injured vessels. Immunohistochemical stainings revealed the presence of Slit2 within the vessel wall and in the perivascular vasa vasorum of naive and injured arteries. Double immunohistochemical analyses showed that infiltrating monocytes expressed Slit2 in the perivascular and adventitial tissues of injured arteries 1 and 3 days postangioplasty. In addition, recombinant full-length Slit2 and Slit2-N/1118, an N-terminal fragment of Slit2, inhibited stromal cell-derived factor 1-mediated migration of circulating rat peripheral blood mononuclear cells. In summary, adventitial activation of CAM genes and neutrophil infiltration preceded

  6. Glucose and auxin signaling interaction in controlling Arabidopsis thaliana seedlings root growth and development.

    Directory of Open Access Journals (Sweden)

    Bhuwaneshwar S Mishra

    Full Text Available BACKGROUND: Plant root growth and development is highly plastic and can adapt to many environmental conditions. Sugar signaling has been shown to affect root growth and development by interacting with phytohormones such as gibberellins, cytokinin and abscisic acid. Auxin signaling and transport has been earlier shown to be controlling plant root length, number of lateral roots, root hair and root growth direction. PRINCIPAL FINDINGS: Increasing concentration of glucose not only controls root length, root hair and number of lateral roots but can also modulate root growth direction. Since root growth and development is also controlled by auxin, whole genome transcript profiling was done to find out the extent of interaction between glucose and auxin response pathways. Glucose alone could transcriptionally regulate 376 (62% genes out of 604 genes affected by IAA. Presence of glucose could also modulate the extent of regulation 2 fold or more of almost 63% genes induced or repressed by IAA. Interestingly, glucose could affect induction or repression of IAA affected genes (35% even if glucose alone had no significant effect on the transcription of these genes itself. Glucose could affect auxin biosynthetic YUCCA genes family members, auxin transporter PIN proteins, receptor TIR1 and members of a number of gene families including AUX/IAA, GH3 and SAUR involved in auxin signaling. Arabidopsis auxin receptor tir1 and response mutants, axr2, axr3 and slr1 not only display a defect in glucose induced change in root length, root hair elongation and lateral root production but also accentuate glucose induced increase in root growth randomization from vertical suggesting glucose effects on plant root growth and development are mediated by auxin signaling components. CONCLUSION: Our findings implicate an important role of the glucose interacting with auxin signaling and transport machinery to control seedling root growth and development in changing nutrient

  7. Developments in ROOT I/O and trees

    CERN Document Server

    Brun, R; Frank, M; Kreshuk, A; Linev, S; Russo, P; Rademakers, F

    2008-01-01

    For the last several months the main focus of development in the ROOT I/O package has been code consolidation and performance improvements. Access to remote files is affected both by bandwidth and latency. We introduced a pre-fetch mechanism to minimize the number of transactions between client and server and hence reducing the effect of latency. We will review the implementation and how well it works in different conditions (gain of an order of magnitude for remote file access). We will also review new utilities, including a faster implementation of TTree cloning (gain of an order of magnitude), a generic mechanism for object references, and a new entry list mechanism tuned both for small and large number of selections. In addition to reducing the coupling with the core module and becoming its owns library (libRIO) (as part of the general restructuration of the ROOT libraries), the I/O package has been enhanced in the area of XML and SQL support, thread safety, schema evolution, TTreeFormula, and many other ...

  8. Autologous adventitial overlay method reinforces anastomoses in aortic surgery.

    Science.gov (United States)

    Minato, Naoki; Okada, Takayuki; Sumida, Tomohiko; Watanabe, Kenichi; Maruyama, Takahiro; Kusunose, Takashi

    2014-05-01

    In this study, we present an inexpensive and effective method for providing a secure and hemostatic anastomosis using autologous adventitia obtained from a dissected or aneurysmal wall. The resected aortic wall is separated between the adventitia and media, and a soft, 2 × 10-cm adventitial strip is overlaid to cover the anastomotic margin. A graft is sutured to the aortic stump. This autologous adventitial overlay method can inexpensively and strongly reinforce the anastomosis during aortic surgery for dissection or aneurysm and will contribute to anastomotic hemostasis and long-term stability.

  9. Expression of Root-Related Transcription Factors Associated with Flooding Tolerance of Soybean (Glycine max

    Directory of Open Access Journals (Sweden)

    Babu Valliyodan

    2014-09-01

    Full Text Available Much research has been conducted on the changes in gene expression of the model plant Arabidopsis to low-oxygen stress. Flooding results in a low oxygen environment in the root zone. However, there is ample evidence that tolerance to soil flooding is more than tolerance to low oxygen alone. In this study, we investigated the physiological response and differential expression of root-related transcription factors (TFs associated with the tolerance of soybean plants to soil flooding. Differential responses of PI408105A and S99-2281 plants to ten days of soil flooding were evaluated at physiological, morphological and anatomical levels. Gene expression underlying the tolerance response was investigated using qRT-PCR of root-related TFs, known anaerobic genes, and housekeeping genes. Biomass of flood-sensitive S99-2281 roots remained unchanged during the entire 10 days of flooding. Flood-tolerant PI408105A plants exhibited recovery of root growth after 3 days of flooding. Flooding induced the development of aerenchyma and adventitious roots more rapidly in the flood-tolerant than the flood-sensitive genotype. Roots of tolerant plants also contained more ATP than roots of sensitive plants at the 7th and 10th days of flooding. Quantitative transcript analysis identified 132 genes differentially expressed between the two genotypes at one or more time points of flooding. Expression of genes related to the ethylene biosynthesis pathway and formation of adventitious roots was induced earlier and to higher levels in roots of the flood-tolerant genotype. Three potential flood-tolerance TFs which were differentially expressed between the two genotypes during the entire 10-day flooding duration were identified. This study confirmed the expression of anaerobic genes in response to soil flooding. Additionally, the differential expression of TFs associated with soil flooding tolerance was not qualitative but quantitative and temporal. Functional analyses of

  10. Effects of Water Regime on the Structure of Roots and Stems of Durum Wheat (Triticum durum Desf.

    Directory of Open Access Journals (Sweden)

    Amina Labdelli

    2014-01-01

    Full Text Available Yield improvement of durum wheat is considerably limited by the expression of environmental abiotic factors. Water deficits are one of these limiting factors. Plants develop various strategies to tolerate the effects of water deficit. Some of such mechanisms might occur in the root and stem systems. The present study aimed to investigate some anatomical traits contributing to the drought tolerance in the durum wheat. The anatomical variations of the meristem of roots and stems, as a response to water deficit, were evaluated. The results indicated that the enhancement of the intensity of water deficit was accompanied by profound structural changes in the piliferous zone of roots. Water deficit caused a significant decrease in the diameter of the newly formed adventitious roots, which can be explained by a reduction in the thickness of the cortical parenchyma, through the reduction of cell size. This action was usually a contrary effect in the principal adventitious roots. The study also showed that increasing the intensity of water deficit reduced the diameter of vessels in the primary xylem, thereby increasing the hydraulic resistance of roots and lowering the flow of sap.

  11. Rooting of carnation cuttings: The auxin signal

    OpenAIRE

    Acosta, Manuel; Oliveros-Valenzuela, M Rocío; Nicolás, Carlos; Sánchez-Bravo, José

    2009-01-01

    The rooting of stem cuttings is a common vegetative propagation practice in many ornamental species. Among other signals, auxin polarly transported through the stem plays a key role in the formation and growth of adventitious roots. Unlike in other plant species, auxin from mature leaves plays a decisive role in the rooting of carnation (Dianthus caryophyllus. L) cuttings. The gene DcAUX1, which codifies an auxin influx carrier involved in polar auxin transport, has now been cloned and charac...

  12. Effect of pectin methylesterase gene expression on pea root development.

    Science.gov (United States)

    Wen, F; Zhu, Y; Hawes, M C

    1999-06-01

    Expression of an inducible gene with sequences common to genes encoding pectin methylesterase (PME) was found to be tightly correlated, both spatially and temporally, with border cell separation in pea root caps. Partial inhibition of the gene's expression by antisense mRNA in transgenic pea hairy roots prevented the normal separation of root border cells from the root tip into the external environment. This phenotype was correlated with an increase in extracellular pH, reduced root elongation, and altered cellular morphology. The translation product of the gene exhibited PME activity in vitro. These results are consistent with the long-standing hypothesis that the demethylation of pectin by PME plays a key role in cell wall metabolism.

  13. Rapid crown root development confers tolerance to zinc deficiency in rice

    Directory of Open Access Journals (Sweden)

    Amrit Kaur eNanda

    2016-03-01

    Full Text Available Zinc (Zn deficiency is one of the leading nutrient disorders in rice (Oryza sativa. Many studies have identified Zn efficient rice genotypes, but causal mechanisms for Zn deficiency tolerance remain poorly understood. Here we report a detailed study of the impact of Zn deficiency on crown root development of rice genotypes, differing in their tolerance to this stress. Zn deficiency delayed crown root development and plant biomass accumulation in both Zn efficient and inefficient genotypes, with the effects being much stronger in the latter. Zn efficient genotypes had developed new crown roots as early as three days after transplanting (DAT to a Zn deficient field and that was followed by a significant increase in total biomass by 7 DAT. Zn-inefficient genotypes developed few new crown roots and did not increase biomass during the first seven days following transplanting. This correlated with Zn efficient genotypes retranslocating a higher proportion of shoot Zn to their roots, compared to Zn inefficient genotypes. These latter genotypes were furthermore not efficient in utilizing the limited Zn for root development. Histological analyses indicated no anomalies in crown tissue of Zn-efficient or inefficient genotypes that would have suggested crown root emergence was impeded. We therefore conclude that the rate of crown root initiation was differentially affected by Zn deficiency between genotypes. Rapid crown root development, following transplanting, was identified as a main causative trait for tolerance to Zn deficiency and better Zn retranslocation from shoot to root was a key attribute of Zn-efficient genotypes.

  14. [The mechanism of root hair development and molecular regulation in plants].

    Science.gov (United States)

    Wang, Yue-Ping; Li, Ying-Hui; Guan, Rong-Xia; Liu, Zhang-Xiong; Chen, Xiong-Ting; Chang, Ru-Zhen; Qiu, Li-Juan

    2007-04-01

    The formation of the root epidermis in Arabidopsis thaliana provides a simple model to study mechanisms underlying patterning in plants. Root hair increases the root surface area and effectively increases the root diameter, so root hair is thought to aid plants in nutrient uptake, anchorage and microbe interactions. The determination of root hair development has two types, lateral inhibition with feedback and position-dependent pattern of cell differentiation. The initiation and development of root hair in Arabidopsis provide a simple and efficacious model for the study of cell fate determination in plants. Molecular genetic studies identify a suite of putative transcription factors which regulate the epidermal cell pattern. The homeodomain protein GLABRA2 (GL2), R2R3 MYB-type transcription factor WEREWOLF (WER) and WD-repeat protein TRANSPARENTT TESTA GLABRA (TTG) are required for specification of non-hair cell type. The CAPRICE (CPC) and TRYPTICHON (TRY) are involved in specifying the hair cell fate.

  15. Balancing Water Uptake and Loss through the Coordinated Regulation of Stomatal and Root Development.

    Directory of Open Access Journals (Sweden)

    Christopher Hepworth

    Full Text Available Root development is influenced by nutrient and water availabilities. Plants are able to adjust many attributes of their root in response to environmental signals including the size and shape of the primary root, lateral roots and root hairs. Here we investigated the response of roots to changes in the levels of leaf transpiration associated with altered stomatal frequency. We found that plants with high stomatal density and conductance produce a larger rooting area and as a result have enhanced phosphate uptake capacity whereas plants with low stomatal conductance produce a smaller root. Manipulating the growth environment of plants indicated that enhanced root growth is most likely a result of an increased demand for water rather than phosphate. Plants manipulated to have an increase or reduction in root hair growth show a reduction or increase respectively, in stomatal conductance and density. Our results demonstrate that plants can balance their water uptake and loss through coordinated regulation of both stomatal and root development.

  16. Weekly doxorubicin increases coronary arteriolar wall and adventitial thickness.

    Directory of Open Access Journals (Sweden)

    Delrae M Eckman

    Full Text Available BACKGROUND: Doxorubicin (DOX is associated with premature cardiovascular events including myocardial infarction. This study was performed to determine if the weekly administration of DOX influenced coronary arteriolar medial and/or adventitial wall thickening. METHODS: Thirty-two male Sprague-Dawley rats aged 25.1± 2.4 weeks were randomly divided into three groups and received weekly intraperitoneal injections of normal saline (saline, n = 7, or low (1.5 mg/kg to 1.75 mg/kg, n = 14 or high (2.5 mg/kg, n = 11 doses of DOX. The animals were treated for 2-12 weeks, and euthanized at pre-specified intervals (2, 4, 7, or 10+ weeks to obtain histopathologic assessments of coronary arteriolar lumen diameter, medial wall thickness, adventitial wall thickness, and total wall thickness (medial thickness + adventitial thickness. RESULTS: Lumen diameter was similar across all groups (saline: 315±34 µm, low DOX: 286±24 µm, high DOX: 242±27 µm; p = 0.22. In comparison to animals receiving weekly saline, animals receiving weekly injections of 2.5 mg/kg of DOX experienced an increase in medial (23±2 µm vs. 13±3 µm; p = 0.005, and total wall thickness (51±4 µm vs. 36±5 µm; p = 0.022, respectively. These increases, as well as adventitial thickening became more prominent after normalizing for lumen diameter (p<0.05 to p<0.001 and after adjusting for age, weight, and total cumulative DOX dose (p = 0.02 to p = 0.01. Animals receiving low dose DOX trended toward increases in adventitial and total wall thickness after normalization to lumen diameter and accounting for age, weight, and total cumulative DOX dose (p = 0.06 and 0.09, respectively. CONCLUSION: In conclusion, these data demonstrate that weekly treatment of rats with higher doses of DOX increases coronary arteriolar medial, adventitial, and total wall thickness. Future studies are warranted to determine if DOX related coronary arteriolar effects are

  17. Root border cell development is a temperature-insensitive and Al-sensitive process in barley.

    Science.gov (United States)

    Pan, Jian-Wei; Ye, Dan; Wang, Li-Ling; Hua, Jing; Zhao, Gu-Feng; Pan, Wei-Huai; Han, Ning; Zhu, Mu-Yuan

    2004-06-01

    In vivo and in vitro experiments showed that border cell (BC) survival was dependent on root tip mucigel in barley (Hordeum vulgare L. cv. Hang 981). In aeroponic culture, BC development was an induced process in barley, whereas in hydroponic culture, it was a kinetic equilibrium process during which 300-400 BCs were released into water daily. The response of root elongation to temperatures (10-35 degrees C) was very sensitive but temperature changes had no great effect on barley BC development. At 35 degrees C, the root elongation ceased whereas BC production still continued, indicating that the two processes might be regulated independently under high temperature (35 degrees C) stress. Fifty microM Al could inhibit significantly BC development by inhibiting pectin methylesterase activity in the root cap of cv. 2000-2 (Al-sensitive) and cv. Humai 16 (Al-tolerant), but 20 microM Al could not block BC development in cv. Humai 16. BCs and their mucigel of barley had a limited role in the protection of Al-induced inhibition of root elongation, but played a significant role in the prevention of Al from diffusing into the meristems of the root tip and the root cap. Together, these results suggested that BC development was a temperature-insensitive but Al-sensitive process, and that BCs and their mucigel played an important role in the protection of root tip and root cap meristems from Al toxicity.

  18. The Emerging Role of Reactive Oxygen Species Signaling during Lateral Root Development.

    Science.gov (United States)

    Manzano, Concepción; Pallero-Baena, Mercedes; Casimiro, Ilda; De Rybel, Bert; Orman-Ligeza, Beata; Van Isterdael, Gert; Beeckman, Tom; Draye, Xavier; Casero, Pedro; Del Pozo, Juan C

    2014-07-01

    Overall root architecture is the combined result of primary and lateral root growth and is influenced by both intrinsic genetic programs and external signals. One of the main questions for root biologists is how plants control the number of lateral root primordia and their emergence through the main root. We recently identified S-phase kinase-associated protein2 (SKP2B) as a new early marker for lateral root development. Here, we took advantage of its specific expression pattern in Arabidopsis (Arabidopsis thaliana) in a cell-sorting and transcriptomic approach to generate a lateral root-specific cell sorting SKP2B data set that represents the endogenous genetic developmental program. We first validated this data set by showing that many of the identified genes have a function during root growth or lateral root development. Importantly, genes encoding peroxidases were highly represented in our data set. Thus, we next focused on this class of enzymes and showed, using genetic and chemical inhibitor studies, that peroxidase activity and reactive oxygen species signaling are specifically required during lateral root emergence but, intriguingly, not for primordium specification itself.

  19. The Emerging Role of Reactive Oxygen Species Signaling during Lateral Root Development1[C][W

    Science.gov (United States)

    Manzano, Concepción; Pallero-Baena, Mercedes; Casimiro, Ilda; De Rybel, Bert; Orman-Ligeza, Beata; Van Isterdael, Gert; Beeckman, Tom; Draye, Xavier; Casero, Pedro; del Pozo, Juan C.

    2014-01-01

    Overall root architecture is the combined result of primary and lateral root growth and is influenced by both intrinsic genetic programs and external signals. One of the main questions for root biologists is how plants control the number of lateral root primordia and their emergence through the main root. We recently identified S-phase kinase-associated protein2 (SKP2B) as a new early marker for lateral root development. Here, we took advantage of its specific expression pattern in Arabidopsis (Arabidopsis thaliana) in a cell-sorting and transcriptomic approach to generate a lateral root-specific cell sorting SKP2B data set that represents the endogenous genetic developmental program. We first validated this data set by showing that many of the identified genes have a function during root growth or lateral root development. Importantly, genes encoding peroxidases were highly represented in our data set. Thus, we next focused on this class of enzymes and showed, using genetic and chemical inhibitor studies, that peroxidase activity and reactive oxygen species signaling are specifically required during lateral root emergence but, intriguingly, not for primordium specification itself. PMID:24879433

  20. Mechanisms of waterlogging tolerance in wheat - a review of root and shoot physiology

    DEFF Research Database (Denmark)

    Herzog, Max; Striker, Gustavo G; Colmer, Timothy D;

    2016-01-01

    We review the detrimental effects of waterlogging on physiology, growth and yield of wheat. We highlight traits contributing to waterlogging tolerance and genetic diversity in wheat. Death of seminal roots and restriction of adventitious root length due to O2 deficiency result in low root...

  1. Auxin and ethylene response interactions during Arabidopsis root hair development dissected by auxin influx modulators.

    Science.gov (United States)

    Rahman, Abidur; Hosokawa, Satoko; Oono, Yutaka; Amakawa, Taisaku; Goto, Nobuharu; Tsurumi, Seiji

    2002-12-01

    The plant hormones auxin and ethylene have been shown to play important roles during root hair development. However, cross talk between auxin and ethylene makes it difficult to understand the independent role of either hormone. To dissect their respective roles, we examined the effects of two compounds, chromosaponin I (CSI) and 1-naphthoxyacetic acid (1-NOA), on the root hair developmental process in wild-type Arabidopsis, ethylene-insensitive mutant ein2-1, and auxin influx mutants aux1-7, aux1-22, and double mutant aux1-7 ein2. Beta-glucuronidase (GUS) expression analysis in the BA-GUS transgenic line, consisting of auxin-responsive domains of PS-IAA4/5 promoter and GUS reporter, revealed that 1-NOA and CSI act as auxin uptake inhibitors in Arabidopsis roots. The frequency of root hairs in ein2-1 roots was greatly reduced in the presence of CSI or 1-NOA, suggesting that endogenous auxin plays a critical role for the root hair initiation in the absence of an ethylene response. All of these mutants showed a reduction in root hair length, however, the root hair length could be restored with a variable concentration of 1-naphthaleneacetic acid (NAA). NAA (10 nM) restored the root hair length of aux1 mutants to wild-type level, whereas 100 nM NAA was needed for ein2-1 and aux1-7 ein2 mutants. Our results suggest that insensitivity in ethylene response affects the auxin-driven root hair elongation. CSI exhibited a similar effect to 1-NOA, reducing root hair growth and the number of root hair-bearing cells in wild-type and ein2-1 roots, while stimulating these traits in aux1-7and aux1-7ein2 roots, confirming that CSI is a unique modulator of AUX1.

  2. Classifying stages of third molar development: crown length as a predictor for the mature root length.

    Science.gov (United States)

    Altalie, Salem; Thevissen, Patrick; Willems, Guy

    2015-01-01

    Multiple tooth development staging techniques were reported based on arbitrarily set borderlines between succeeding stages. Anatomic tooth features or predictions of future tooth part dimensions were described to identify the thresholds between the established stages. The need to predict mature tooth dimensions, while the tooth considered is still in development, is a drawback to use this staging technique for dental age estimations. Using the fully mature crown length as a predictor for the future root length could provide a tool for undisputable staging. The aim of this study was first to measure the crown and root length of fully mature third molars and second to investigate whether the crown length could be used as a predictor of the root length, in order to classify the observed root length as a proportion of the future mature root. The crown and root lengths of all present third molars were digitally measured on dental panoramic radiographs of 1,000 subjects. The included subjects were equally distributed in gender, and their age ranged between 22 and 40 years. Two occlusal borders, the cement enamel junction and the root apices, were defined as landmarks for standardized measurements. Regression models with root length as response and crown length as predictor were established and revealed low R (2) and high RMSE values. Due to the small explained variance by the prediction models and the high variation in prediction errors, the observed crown length cannot be used to predict the final root length of a developing third molar.

  3. Hydrogen peroxide modulates abscisic acid signaling in root growth and development in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    BAI Ling; ZHOU Yun; ZHANG XiaoRan; SONG ChunPeng; Gao MingQing

    2007-01-01

    Exogenous abscisic acid (ABA) can inhibit root growth and promote formation of more root hairs in the root tip of Arabidopsis. However, the molecular mechanisms that underlie root ABA signaling are largely unknown. We report here that hydrogen peroxide (H2O2) reduces the root growth of wild type,and the phenotype of H2O2 on the root growth is similar to ABA response. Meanwhile ABA-induced changes in the morphology of root system can be partly reversed by ascorbic acid in wild type and abolished in NADPH oxidase defective mutant atrbohF and atrbohC. Further, ABA can induce H2O2 accumulation in the root cells and enhance transcription level of OXI1, which is necessary for many more AOS-dependent processes such as root hair growth in Arabidopsis. Our results suggest that H2O2 as an important signal molecule is required for the ABA-regulated root growth and development in Arabidopsis.

  4. Effects of mechanical vibration on root development of Actinidia chinensis plantlet

    Institute of Scientific and Technical Information of China (English)

    YANG Xiao-cheng; DING Jian-ping; WANG Bo-chu

    2007-01-01

    The root development of Actinidia chinensis plantlets was studied in exposure to environmental stress of mechanical vibration at respectively 1 Hz, 2 Hz, 3 Hz, 4 Hz and 5 Hz. The plantlets exposed to vibration stimuli at all those frequencies have a larger total number and a larger total length of roots and a smaller permeability of root plasma-membrane, compared with those cultivated in an environment without vibration stress. Vibration at respectively 1 Hz, 2 Hz, 3 Hz and 4 Hz enhances root activity and the 3 Hz vibration is the most favorable. There is an obvious negative correlation between root activity and permeability of root plasma-membrane. The effects may be explained by the likelihood that mechanical vibration at an appropriate frequency facilitates roots' absorbing water and minerals which are indispensable to inducing and synthesizing in roots some active substances favorable to growth. Nevertheless, overstress damages the integrity of root plasm-membrane, increases the permeability, and results in the disability of protecting root cells.

  5. The occurrence of dauciform roots amongst Western Australian reeds, rushes and sedges, and the impact of phosphorus supply on dauciform-root development in Schoenus unispiculatus (Cyperaceae).

    Science.gov (United States)

    Shane, Michael W; Dixon, Kingsley W; Lambers, Hans

    2005-03-01

    * The incidence of species that develop specialised 'dauciform' lateral roots, which are hypothesised to be important for phosphorus (P) acquisition, is uncertain. We investigated their occurrence in Australian reed, rush and sedge species, grown at low P concentration in nutrient solution, and studied the response of Schoenus unispiculatus (Cyperaceae) to a range of P concentrations. * We assessed the fraction of root biomass invested in dauciform roots, their respiration and net P-uptake rate, and the P status of roots and leaves. * Dauciform-root development occurred only in particular genera of Cyperaceae when grown at low P supply. Increased P supply was associated with increased growth of S. unispiculatus and increased leaf [P]. Dauciform-root growth was reduced by increased P supply, and reduced P uptake co-occurred with the complete suppression of dauciform roots. * The P-induced suppression of dauciform roots in Cyperaceae is similar to that observed for proteoid roots in members of Proteaceae and Lupinus albus. The response of dauciform roots to altered P supply and their absence from root systems of some sedge species are discussed in terms of managed and natural systems.

  6. Nitric oxide mediates alginate oligosaccharides-induced root development in wheat (Triticum aestivum L.).

    Science.gov (United States)

    Zhang, Yunhong; Liu, Hang; Yin, Heng; Wang, Wenxia; Zhao, Xiaoming; Du, Yuguang

    2013-10-01

    Alginate oligosaccharides (AOS), which are marine oligosaccharides, are involved in regulating plant root growth, but the promotion mechanism for AOS remains unclear. Here, AOS (10-80 mg L(-1)) were found to induce the generation of nitric oxide (NO) in the root system of wheat (Triticum aestivum L.), which promoted the formation and elongation of wheat roots in a dose-dependent manner. NO inhibitors suggested that nitrate reductase (NR), rather than nitric oxide synthase (NOS), was essential for AOS-induced root development. Further studies confirmed that AOS-induced NO generation in wheat roots by up-regulating the gene expression and enzyme activity of NR at the post-transcriptional level. The anatomy and RT-PCR results showed that AOS accelerated the division and growth of stele cells, leading to an increase in the ratio of stele area to root transverse area. This could be inhibited by the NR inhibitor, sodium tungstate, which indicated that NO catalyzed by the NR was involved in AOS regulation of root development. Taken together, in the early stage of AOS-induced root development, NO generation was a novel mechanism by which AOS regulated plant growth. The results also showed that this marine resource could be widely used for crop development.

  7. Impaired tooth root development after treatment of a cerebellar astrocytoma: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Eckles, T.A.; Kalkwarf, K.L.

    1989-10-01

    A young man, previously treated by surgical resection of a grade III cerebellar astrocytoma in combination with irradiation and chemotherapy, was found to display severe generalized root agenesis. This patient also exhibited secondary hypothyroidism and decreased levels of growth hormone. These factors are discussed in relation to their possible role in impaired root development.

  8. Root development of permanent lateral incisor in cleft lip and palate children: A radiographic study

    Directory of Open Access Journals (Sweden)

    Amarlal Deepti

    2007-01-01

    Full Text Available Objective: The objective of this study was to compare the root development of lateral incisor on the cleft side with the root development of its contralateral tooth in cleft lip and palate children. Setting: Cleft lip and palate wing, Meenakshi Ammal Dental College and Hospital, Chennai, South India. Materials and Methods: A sample of 96 orthopantamograms of patients with unilateral or bilateral cleft lip and/or cleft palate was selected, regardless of sex and race. Main Outcome Measure: Orthopantamograms were analyzed for root development of lateral incisor on the cleft and noncleft side. Associated anomalies like hypodontia, supernumerary teeth, malformed lateral incisors and root development of canine, if present, were recorded. Findings and Conclusions: Root development of permanent lateral incisor was delayed on the cleft side compared to the noncleft side. There was a statistically significant relationship between levels of root development of lateral incisors on the cleft side within the different study groups ( P < 0.05. Incidence of hypodontia increased in proportion to cleft severity. Frequency of missing second premolars, supernumerary teeth and malformed lateral incisors increased in cleft lip and palate patients. Root development of canine showed a slight delay on the cleft side when compared to the canine on the noncleft side.

  9. Adventitious Bud Induction and Plantlet Regeneration in vitro from Mature Zygotic Embryos of Ponderosa Pine%离体条件下西黄松成熟合子胚不定芽的诱导及植株再生

    Institute of Scientific and Technical Information of China (English)

    李科友; 唐德瑞; 李林; 朱海兰; 赵忠; 侯琳

    2008-01-01

    Adventitious buds were induced from the excised mature zygotic embryos of Ponderosa Pine (Pinus ponderosa). Thehighest induction rate (65.8%) of adventitious buds was obtained with 10-fold multiplication at the highest and 7-foldformation of adventitious buds. Buds proliferation and elongation were achieved on 1/2GD and 1/2SH without growth regulators.A proper amount of activated charcoal promoted adventitious buds elongation and root' growth. The adventitious shoots ofPonderosa Pine were used to induce adventitious roots on 1/2GD and 1/2SH media supplemented with different concentrations ofNAA and GA . The results showed that NAA played a determinative role in initiating the adventitious roots. Sixteen point sevenpaper, the experimental results showed that roots were successfully induced from cultured mature zygotic embryos of PonderosaPine.%以西黄松成熟胚为外植体诱导不定芽,在GD+9.85~19.70 μmol·L'-1 6-BA+0.0~14.42 μmol·L-1 NAA上不定芽诱导率最高达65.8%,平均增殖率为7,最大增殖率达10;不定芽形成有2种途径,即子叶直接形成不定芽和子叶组织再分化形成不定芽;NAA不利于外植体不定芽的诱导;不定芽的生长和扩繁采用不加生长调节剂的1/2 GD和1/2 SH培养基;培养基中加入适量的活性炭有利于不定芽和根的生长.不定嫩梢在1/2 GD和1/2 SH附加不同浓度NAA和GA,3的培养基上进行生根诱导,试验结果表明:NAA对不定根的形成起主要作用,在1/2 GD+28.84 μmol·L'-1 NAA+4.17 μmol·L'-1 GA,3培养基中不定梢的生根率为16.7%.在离体培养条件下,以西黄松成熟胚为外植体获得了再生植株.

  10. Arabidopsis NAC1 transduces auxin signal downstream of TIR1 to promote lateral root development.

    Science.gov (United States)

    Xie, Q; Frugis, G; Colgan, D; Chua, N H

    2000-12-01

    Auxin plays a key role in lateral root formation, but the signaling pathway for this process is poorly understood. We show here that NAC1, a new member of the NAC family, is induced by auxin and mediates auxin signaling to promote lateral root development. NAC1 is a transcription activator consisting of an N-terminal conserved NAC-domain that binds to DNA and a C-terminal activation domain. This factor activates the expression of two downstream auxin-responsive genes, DBP and AIR3. Transgenic plants expressing sense or antisense NAC1 cDNA show an increase or reduction of lateral roots, respectively. Finally, TIR1-induced lateral root development is blocked by expression of antisense NAC1 cDNA, and NAC1 overexpression can restore lateral root formation in the auxin-response mutant tir1, indicating that NAC1 acts downstream of TIR1.

  11. Tree-Substrate Water Relations and Root Development in Tree Plantations Used for Mine Tailings Reclamation.

    Science.gov (United States)

    Guittonny-Larchevêque, Marie; Bussière, Bruno; Pednault, Carl

    2016-05-01

    Tree water uptake relies on well-developed root systems. However, mine wastes can restrict root growth, in particular metalliferous mill tailings, which consist of the finely crushed ore that remains after valuable metals are removed. Thus, water stress could limit plantation success in reclaimed mine lands. This study evaluates the effect of substrates varying in quality (topsoil, overburden, compost and tailings mixture, and tailings alone) and quantity (50- or 20-cm-thick topsoil layer vs. 1-m plantation holes) on root development and water stress exposure of trees planted in low-sulfide mine tailings under boreal conditions. A field experiment was conducted over 2 yr with two tree species: basket willow ( L.) and hybrid poplar ( Moench × A. Henry). Trees developed roots in the tailings underlying the soil treatments despite tailings' low macroporosity. However, almost no root development occurred in tailings underlying a compost and tailings mixture. Because root development and associated water uptake was not limited to the soil, soil volume influenced neither short-term (water potential and instantaneous transpiration) nor long-term (δC) water stress exposure in trees. However, trees were larger and had greater total leaf area when grown in thicker topsoil. Despite a volumetric water content that always remained above permanent wilting point in the tailings colonized by tree roots, measured foliar water potentials at midday were lower than drought thresholds reported for both tested tree species.

  12. Inhibition of growth and development of root border cells in wheat by Al.

    Science.gov (United States)

    Zhu, Mu-Yuan; Ahn, Sung-Ju; Matsumoto, Hideaki

    2003-03-01

    The production and development of border cells vary with genotype, and they are released in wheat at an earlier stage of root development than other species studied so far. No significant difference was observed in the maximum number of border cells between Al-tolerant (Atlas 66) and Al-sensitive (Scout 66) cultivars in the absence of Al treatment. Al seriously inhibited the production and release of border cells, resulting in clumping of border cells in Scout 66, but less clustering in Atlas 66. The number of border cells released from roots treated with Al is significantly less than that from roots grown without Al treatment. Al treatment induced the death of detached border cells in vitro and they were killed by a 20-h treatment with 25 micro m Al. No significant difference in survival percentage of detached border cells was observed between Atlas 66 and Scout 66, regardless of the presence or absence of Al. The removal of border cells from root tips of both Atlas 66 and Scout 66 enhanced the Al-induced inhibition of root elongation concomitant with increased Al accumulation in the root. These results suggest that border cells adhered to the root tips play a potential role in the protection of root from Al injury in wheat.

  13. DEVELOPMENT OF MICROFLORA IN APPLE ROOT RHIZOSPERE WHEN FERTILIZING

    Directory of Open Access Journals (Sweden)

    Kuzin A. I.

    2015-09-01

    Full Text Available The problem of environmental safety of agricultural products and agro-technical measures is very urgent now. Various agrochemicals are widely used in agricultural production: plant protection preparations, fertilizers, stimulants and plant growth regulators, etc. One possible solution of this problem may be a partial replacement of mineral fertilizers by bacterial ones. The aim of our research was to determine the effect of different fertilizers and methods of their application on the quantity of microorganisms in the apple root rhizosphere soil. The research was carried out according to conventional methods. In our experiment, we determined the number of microorganisms in the rhizosphere of the roots of apple trees, nitrogen, phosphorus and potassium in the leaves; hydrolysable nitrogen, available phosphorus and exchangeable potassium in soil and crop yield. The highest yield was obtained by fertigation in our research. Application bacterial fertilizer to the soil ensured yield increase at the level of mineral fertilizer application. Application of fertilizers in general, in the studied application rates provided optimum level of nitrogen, phosphorus and potassium content in the leaves and soil. By use of fertigation and bacterial fertilizers were high and relatively stable numbers of microorganisms in the rhizosphere of the apple trees. The number of microorganisms in the rhizosphere had a positive correlation with yield and the content of nutrients in soil and in leaves

  14. Structure and development of stomata on the primary root of Ceratonia siliqua L.

    Science.gov (United States)

    Christodoulakis, N S; Menti, J; Galatis, B

    2002-01-01

    Stomata of various sizes are produced on the primary root of Ceratonia siliqua L. Most are generated during embryogenesis, prior to seed desiccation. They can be detected on the dry embryo in a wide zone just above the root tip. Initially, large stomata are formed. These have the ability to induce divisions of their neighbouring cells, creating particular cell patterns around them. Later, small perigenous stomata are generated. As the root grows following seed germination, the stomatal zone overlaps with that of the root hairs. Although root stomata of C. siliqua undergo a structural differentiation that seems almost identical to that of the elliptical stomata formed on leaves, they are unable to move and remain permanently open. Polarizing microscopy of fully differentiated stomata and young stomata at the stage of stomatal pore formation revealed deposition of radial cellulose microfibril systems on their periclinal walls. However, these systems were less developed than those on leaf stomata, a feature that might be responsible for their inactivity. Besides, plastids of the root guard cells (GCs) do not differentiate into chloroplasts but function solely as amyloplasts. Root stomata have a short life span. During rapid and intense root growth, GCs cannot keep pace with the elongation of their neighbouring rhizodermal cells. They therefore split in their mid-region, transversely to the stoma axis. The two parts of the transversely torn stoma are dragged apart and a large opening is formed on the root surface, just above the substomatal cavity. The root stomata, together with these openings, may facilitate increased gaseous exchange during respiration and/or an increased transfer of some nutrients and water in the rapidly growing primary root.

  15. Functions of Nitric Oxide (NO in Roots during Development and under Adverse Stress Conditions

    Directory of Open Access Journals (Sweden)

    Francisco J. Corpas

    2015-05-01

    Full Text Available The free radical molecule, nitric oxide (NO, is present in the principal organs of plants, where it plays an important role in a wide range of physiological functions. Root growth and development are highly regulated by both internal and external factors such as nutrient availability, hormones, pattern formation, cell polarity and cell cycle control. The presence of NO in roots has opened up new areas of research on the role of NO, including root architecture, nutrient acquisition, microorganism interactions and the response mechanisms to adverse environmental conditions, among others. Additionally, the exogenous application of NO throughout the roots has the potential to counteract specific damages caused by certain stresses. This review aims to provide an up-to-date perspective on NO functions in the roots of higher plants.

  16. Cytological studies on adventitious shoots and minitubers of a monoploid potato clone

    NARCIS (Netherlands)

    Hermelink, J; Jacobsen, Evert; Pijnacker, Laas; Witholt, Bernard; de Vries, J.N.; Feenstra, W.J.

    1988-01-01

    A three step procedure for adventitious shoot regeneration on leaf explants of monoploid potato clone H7322 and a minituber induction procedure on stem segments have been described. Chromosome counts on 92 adventitious shoots showed that 85% of them had been polyploidized, i.e., 71% were diploid, 1%

  17. Development of the Poplar-Laccaria bicolor Ectomycorrhiza Modifies Root Auxin Metabolism, Signaling, and Response.

    Science.gov (United States)

    Vayssières, Alice; Pěnčík, Ales; Felten, Judith; Kohler, Annegret; Ljung, Karin; Martin, Francis; Legué, Valérie

    2015-09-01

    Root systems of host trees are known to establish ectomycorrhizae (ECM) interactions with rhizospheric fungi. This mutualistic association leads to dramatic developmental modifications in root architecture, with the formation of numerous short and swollen lateral roots ensheathed by a fungal mantle. Knowing that auxin plays a crucial role in root development, we investigated how auxin metabolism, signaling, and response are affected in poplar (Populus spp.)-Laccaria bicolor ECM roots. The plant-fungus interaction leads to the arrest of lateral root growth with simultaneous attenuation of the synthetic auxin response element DR5. Measurement of auxin-related metabolites in the free-living partners revealed that the mycelium of L. bicolor produces high concentrations of the auxin indole-3-acetic acid (IAA). Metabolic profiling showed an accumulation of IAA and changes in the indol-3-pyruvic acid-dependent IAA biosynthesis and IAA conjugation and degradation pathways during ECM formation. The global analysis of auxin response gene expression and the regulation of AUXIN SIGNALING F-BOX PROTEIN5, AUXIN/IAA, and AUXIN RESPONSE FACTOR expression in ECM roots suggested that symbiosis-dependent auxin signaling is activated during the colonization by L. bicolor. Taking all this evidence into account, we propose a model in which auxin signaling plays a crucial role in the modification of root growth during ECM formation.

  18. Development of tuberous roots and sugar accumulation as related to invertase activity and mineral nutrition.

    Science.gov (United States)

    Ricardo, C P; Sovia, D

    1974-03-01

    Sucrose storage in tuberous roots was not observed when the tissues had very high activities of acid invertase. High activities of the enzyme were always present in the roots at early stages of their development. In species where the activity of the enzyme decreased during root development, sucrose was stored. Thus, acid invertase was undetectable in mature roots of carrots (Daucus carota L.) where sucrose formed almost 80% of the dry matter. Conversely, radish (Raphanus sativus L.) and turnip (Brassica rapa L.) roots, in which the activity of the enzyme remained high until maturity, did not store appreciable amounts of sucrose (2% and 9%, respectively, of the dry matter in the mature roots), reducing sugars being the main reserve (more than 80% of the dry matter in mature turnips). The correlation between sucrose content and acid invertase activity was furthermore evident in both sucrose- and hexose-storing roots when the activity of this enzyme was affected by changes in the mineral nutrition. Deficiencies of nitrogen and sulphur reduced the activity of acid and alkaline invertases and led to increase in sucrose content and decrease in reducing sugars. However, the decline of alkaline invertase activity in tissues low in acid invertase had no clear effect on sugar content. Sodium chloride (10(-1)M) affected acid invertase and sugars in a manner similar to that of the two deficiencies, but had practically no effect on alkaline invertase. The changes in sugar content produced by the variations in mineral nutrition were small in hexose-storing roots in relation to those of sucrose-storing roots. It is possible that this result is related to the different levels of acid invertase in the two types of roots.

  19. [Induction of polyploid hairy roots and its plant regeneration in Pogostemon cablin].

    Science.gov (United States)

    Shi, Heping; Yu, Wu; Zhang, Guopeng; Tsang, Pokeung Eric; Chow, Cheuk Fai Stephen

    2014-08-01

    Abstract: In order to enhance the content of secondary metabolites patchouli alcohol in Pogostemon cablin, we induced polyploid hairy roots and their plant regeneration, and determined the content of patchouli alcohol through artificial chromosome doubling with colchicine. The highest rate of polyploidy induction was more than 40% when hairy roots were treated with 0.05% colchicine for 36 h. The obtained polyploid hairy roots formed adventitious shoots when cultured in an MS medium with 6-BA 0.2 mg/L and NAA 0.1 mg/L for 60 d. Compared with the control diploid plants, the polyploid hairy root-regenerated plants of P. cablin had more developed root systems, thicker stems, shorter internodes and longer, wider and thicker leaves. Observation of the chromosome number in their root tip cells reveals that the obtained polyploid regenerated plants were tetraploidy, with 128 (4n = 128) chromosomes. The leaves contained around twice as many stomatal guard cells and chloroplasts as the controls, but the stomatal density declined with increasing ploidy. The stomatal density in diploid plants was around 1.67 times of that in polyploid plants. GC-MS analysis shows that the content of patchouli alcholol in the hairy root-derived polyploid plants was about 4.25 mg/g dry weight, which was 2.3 times of that in diploid plants. The present study demonstrates that polyploidization of hairy roots can stimulate the content of patchouli alcholol in medicinal plant of P. cablin.

  20. Mass culture of mountain Ginseng roots using rare earth elements in bioreactor cultures

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Sung Jin; Kim, Chang Hyun; Kim, Ha Lim [Chonnam National University, Gwangju (Korea, Republic of)

    2010-01-15

    An adventitious roots of mountain ginseng (Panax ginseng C. A. Meyer) was used in this experiments. Various concentration of lanthanide were tested to find out optimal conditions for biomass and ginsenoside contents in mountain ginseng roots. The MS basal medium with 100 {mu}g/L lanthanide created the most optimum condition for growth of adventitious roots of mountain ginseng. Batch culture with 100 {mu}g/L lanthanide and 0.5 g (F.W) inoculation volume produced maximum final biomass of 1.89 g(F.W/flask) within 4 weeks. However, lanthanide was not effect the ginsenoside contents in adventitious roots of mountain ginseng. In bioreactors, 3.23 g F.W./L of biomass were obtained when 100 {mu}g/L lanthanide were added to the MS basal medium at 26 .deg. C

  1. [Induction and in vitro culture of hairy roots of Dianthus caryophyllus and its plant regeneration].

    Science.gov (United States)

    Shi, Heping; Zhu, Yuanfeng; Wang, Bei; Sun, Jiangbing; Huang, Shengqin

    2014-11-01

    To use Agrobacterium rhizogenes-induced hairy roots to create new germplasm of Dianthus caryophyllus, we transformed D. caryophyllus with A. rhizogenes by leaf disc for plant regeneration from hairy roots. The white hairy roots could be induced from the basal surface of leaf explants of D. caryophyllus 12 days after inoculation with A. rhizogenes ATCC15834. The percentage of the rooting leaf explants was about 90% 21 days after inoculation. The hairy roots could grow rapidly and autonomously in liquid or solid phytohormone-free MS medium. The transformation was confirmed by PCR amplification of rol gene of Ri plasmid and silica gel thin-layer chromatography of opines from D. caryophyllus hairy roots. Hairy roots could form light green callus after cultured on MS+6-BA 1.0-3.0 mg/L + NAA 0.1-0.2 mg/L for 15 days. The optimum medium for adventitious shoots formation was MS + 6-BA 2.0 mg/L + NAA 0.02 mg/L, where the rate of adventitious shoot induction was 100% after cultured for 6 weeks. The mean number of adventitious shoot per callus was 30-40. The adventitious shoots can form roots when cultured on phytohormone-free 1/2 MS or 1/2 MS +0.5 mg/L NAA for 10 days. When the rooted plantlets transplanted in the substrate mixed with perlite sand and peat (volume ratio of 1:2), the survival rate was above 95%.

  2. Two SCARECROW-LIKE genes are induced in response to exogenous auxin in rooting-competent cuttings of distantly related forest species.

    Science.gov (United States)

    Sánchez, Conchi; Vielba, Jesús M; Ferro, Enrique; Covelo, Guillermo; Solé, Alicia; Abarca, Dolores; de Mier, Belén S; Díaz-Sala, Carmen

    2007-10-01

    We characterized SCARECROW-LIKE genes induced by auxin in rooting-competent cuttings of two distantly related forest species (Pinus radiata D. Don and Castanea sativa Mill.) before the activation of cell division that results in adventitious root formation. The predicted protein sequences contain domains characteristic of the GRAS protein family and show a strong similarity to the SCARECROW-LIKE proteins, indicating conserved functions of these proteins. Quantitative RT-PCR analysis showed that these genes are expressed at relatively high levels in roots. Induction of increased mRNA levels in rooting-competent cuttings of both species in response to exogenous auxin was observed within the first 24 h of the root induction process, a time when cell reorganization takes place, but before the resumption of cell division and the appearance of adventitious root primordia. These results suggest that SCARECROW-LIKE genes play a role during the earliest stages of adventitious root formation.

  3. The effects of cotton root exudates on the growth and development of Verticillium dahliae

    Institute of Scientific and Technical Information of China (English)

    Yuxiang WU; Weiping FANG; Shuijin ZHU; Kuiying JIN; Daofan JI

    2008-01-01

    The effects of upland cotton root exudates on the growth and development of Verticillium dahliae were studied, through the compared analysis of the root exudates components between the resistant and suscept-ive cotton materials, using a pair of resistant and sus-ceptive isogenic lines to Verticillium wilt, Z5629 and Z421, as well as 4 other upland cotton cultivars with different resistant levels of Verticillium wilt. The results showed that the amino acids in the root exudates of the resistant cultivars were much less than that of the sus-ceptible ones. Compared with the susceptible ones, there were a lack of aspartic acid, threonine, glutamic acid, alanine, isoleucine, leucine, phenylalanine, lysine and proline in the root exudates from the resistant cul-tivars. On the contrary, arginine was lacking in the sus-ceptive cultivars. The saccharide types in the root exudates were no different between the two kinds of cultivars, but the contents of glucose, fructose and suc-rose in the root exudates of the susceptible varieties were much higher than those in the resistant ones. The experiment of Verticillium dahliae culture showed that the cotton root exudates from resistant cultivars can effectively restrain the spore germination and mycelium growth of Verticillium dahliae, and the argi-nine was the leading amino acid in this inhibitory action, besides the nutrition of the root exudates. However, the cotton root exudates from the susceptive cotton cultivars can improve the growth and develop-ment of Verticillium dahliae effectively; among the amino acid in the exudates, alanine was the most active one in this stimulating function.

  4. Photosynthesis of root chloroplasts developed in Arabidopsis lines overexpressing GOLDEN2-LIKE transcription factors.

    Science.gov (United States)

    Kobayashi, Koichi; Sasaki, Daichi; Noguchi, Ko; Fujinuma, Daiki; Komatsu, Hirohisa; Kobayashi, Masami; Sato, Mayuko; Toyooka, Kiminori; Sugimoto, Keiko; Niyogi, Krishna K; Wada, Hajime; Masuda, Tatsuru

    2013-08-01

    In plants, genes involved in photosynthesis are encoded separately in nuclei and plastids, and tight cooperation between these two genomes is therefore required for the development of functional chloroplasts. Golden2-like (GLK) transcription factors are involved in chloroplast development, directly targeting photosynthesis-associated nuclear genes for up-regulation. Although overexpression of GLKs leads to chloroplast development in non-photosynthetic organs, the mechanisms of coordination between the nuclear gene expression influenced by GLKs and the photosynthetic processes inside chloroplasts are largely unknown. To elucidate the impact of GLK-induced expression of photosynthesis-associated nuclear genes on the construction of photosynthetic systems, chloroplast morphology and photosynthetic characteristics in greenish roots of Arabidopsis thaliana lines overexpressing GLKs were compared with those in wild-type roots and leaves. Overexpression of GLKs caused up-regulation of not only their direct targets but also non-target nuclear and plastid genes, leading to global induction of chloroplast biogenesis in the root. Large antennae relative to reaction centers were observed in wild-type roots and were further enhanced by GLK overexpression due to the increased expression of target genes associated with peripheral light-harvesting antennae. Photochemical efficiency was lower in the root chloroplasts than in leaf chloroplasts, suggesting that the imbalance in the photosynthetic machinery decreases the efficiency of light utilization in root chloroplasts. Despite the low photochemical efficiency, root photosynthesis contributed to carbon assimilation in Arabidopsis. Moreover, GLK overexpression increased CO₂ fixation and promoted phototrophic performance of the root, showing the potential of root photosynthesis to improve effective carbon utilization in plants.

  5. Preliminary Observation on Developmental Characteristics of Adventitious Buds of Artemisia frigida Willd.%冷蒿不定芽发育特性的初步观察

    Institute of Scientific and Technical Information of China (English)

    李姗姗; 宛涛; 蔡萍; 伊卫东; 韩轩

    2013-01-01

    对冷蒿不定芽的分布、着生特点、萌生数量及形态结构特征等发育特性的初步观察表明:冷蒿不定芽主要着生于根颈、地表枝条上,其大小、数量以及分布情况各异;不定芽主要产生于返青期到结实期,冷蒿现蕾期和开花期是不定芽萌生的旺盛时期,在根颈处分别有19个和25个,地表枝条上有66个和75个.光镜和扫描电镜观察表明,不定芽具有芽鳞片,包裹着幼叶、叶原基和叶生长点,芽和叶片的表皮被有大量的白色绢毛,发育中的芽体由灰白色转变为绿色,最终发育成叶片和枝条.%The developmental characteristics of adventitious buds of Artemisia frigida Willd. were observed. The results show that the adventitious buds of Artemisia frigida Willd. mainly grow on the rhizome and ground branches,whose size, amount and distribution were different; adventitious buds occurred in May to November, budding stage and flowering stage were period of adventitious buds occurring, there were 19 and 25 adventitious buds on the rhizome and 66 and 75 adventitious buds on the ground branches; by the optical stereoscope and canning electron microscope, the adventitious buds had bud scale, young leaves, leaf primordium and growing tip wrapped in it, the surface of buds and leaves had plenty of white silk wool, the buds turned off-white to green during development, finally formed leaf and branch.

  6. Morpho-anatomical study of Stevia rebaudiana roots grown in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Rafael V. Reis

    Full Text Available ABSTRACT Stevia rebaudiana (Bertoni Bertoni, Asteraceae, is used as a food additive because its leaves are a source of steviol glycosides. There are examples of tissue culture based on micropropagation and phytochemical production of S. rebaudiana leaves but there are few studies on adventitious root culture of S. rebaudiana. More than 90% of the plants used in industry are harvested indiscriminately. In order to overcome this situation, the development of methodologies that employ biotechnology, such as root culture, provides suitable alternatives for the sustainable use of plants. The aim of this study was to compare morpho-anatomical transverse sections of S. rebaudiana roots grown in vitro and in vivo. The in vitro system used to maintain root cultures consisted of a gyratory shaker under dark and light conditions and a roller bottle system. Transverse sections of S. rebaudiana roots grown in vitro were structurally and morphologically different when compared to the control plant; roots artificially maintained in culture media can have their development affected by the degree of media aeration, sugar concentration, and light. GC–MS and TLC confirmed that S. rebaudiana roots grown in vitro have the ability to produce metabolites, which can be similar to those produced by wild plants.

  7. Response of larch root development to annual changes of water conditions in eastern Siberia

    Science.gov (United States)

    Takenaka, Chisato; Miyahara, Mie; Ohta, Takeshi; Maximov, Trofim C.

    2016-06-01

    Eastern Siberia is characterized by continuous permafrost, and has recently been exposed to the effects of climate change. Larch, which is the dominant tree species, has been subject to major environmental changes including fluctuations in soil water content. The purpose of this study was to clarify the responses of mature larch tree roots to changes in soil water conditions. We established a treatment plot in a larch forest, and artificially changed the soil water conditions by covering the ground surface with a vinyl sheet, and from 2004 to 2006 monitored root development through root windows. The vinyl sheet maintained high levels of soil water content, even though the ambient conditions varied from dry in 2004 to wet in 2005 and dry in 2006. In the treatment plot the plants adapted to the wet conditions by decreasing vertical root development. In contrast, roots of plants in the control plot developed to the subsurface layer, even in 2005, and did not develop vertically in 2006 despite the drought. We conclude that larch adapted to the annual changes in soil water content by changing the vertical distribution of roots, and that this reflected a memory effect.

  8. The development dynamics of the maize root transcriptome responsive to heavy metal Pb pollution.

    Science.gov (United States)

    Gao, Jian; Zhang, Yongzhong; Lu, Chaolong; Peng, Hua; Luo, Mao; Li, Gaoke; Shen, Yaou; Ding, Haiping; Zhang, Zhiming; Pan, Guangtang; Lin, Haijian

    2015-03-01

    Lead (Pb), as a heavy metal element, has become the most important metal pollutant of the environment. With allocating a relatively higher proportion of its biomass in roots, maize could be a potential important model to study the phytoremediation of Pb-contaminated soil. Here we analyzed the maize root transcriptome of inbred lines 9782 under heavy metal lead (Pb) pollution, which was identified as a non-hyperaccumulator for Pb in roots. In the present study, more than 98 millions reads were mapped to define gene structure and detect polymorphism, thereby to qualify transcript abundance along roots development under Pb treatment. A total of 17,707, 17,440, 16,998 and 16,586 genes were identified in maize roots at four developmental stages (0, 12 h, 24 h and 48 h) respectively and 2,825, 2,626, 2161 and 2260 stage-specifically expressed genes were also identified respectively. In addition, based on our RNA-Seq data, transcriptomic changes during maize root development responsive to Pb were investigated. A total of 384 differentially expressed genes (DEGs) (log2Ratio ≥ 1, FDR ≤ 0.001) were identified, of which, 36 genes with significant alteration in expression were detected in four developmental stages; 12 DEGs were randomly selected and successful validated by qRT-PCR. Additionally, many transcription factor families might act as the important regulators at different developmental stages, such as bZIP, ERF and GARP et al. These results will expand our understanding of the complex molecular and cellular events in maize root development and provide a foundation for future study on root development in maize under heavy metal pollution and other cereal crops.

  9. Nitric Oxide Functions as a Positive Regulator of Root Hair Development

    Science.gov (United States)

    Lombardo, María Cristina; Graziano, Magdalena; Polacco, Joseph C

    2006-01-01

    The root epidermis is composed of two cell types: trichoblasts (or hair cells) and atrichoblasts (or non-hair cells). In lettuce (Lactuca sativa cv. Grand Rapids var. Rapidmor oscura) plants grown hydroponically in water, the root epidermis did not form root hairs. The addition of 10 µM sodium nitroprusside (SNP), a nitric oxide (NO) donor, resulted in almost all rhizodermal cells differentiated into root hairs. Treatment with the synthetic auxin 1-naphthyl acetic acid (NAA) displayed a significant increase of root hair formation (RHF) that was prevented by the specific NO scavenger carboxy-PTIO (cPTIO). In Arabidopsis, two mutants have been shown to be defective in NO production and to display altered phenotypes in which NO is implicated. Arabidopsis nos1 has a mutation in an NO synthase structural gene (NOS1), and the nia1 nia2 double mutant is null for nitrate reductase (NR) activity. We observed that both mutants were affected in their capacity of developing root hairs. Root hair elongation was significantly reduced in nos1 and nia1 nia2 mutants as well as in cPTIO-treated wild type plants. A correlation was found between endogenous NO level in roots detected by the fluorescent probe DAF-FM DA and RHF. In Arabidopsis, as well as in lettuce, cPTIO blocked the NAA-induced root hair elongation. Taken together, these results indicate that: (1) NO is a critical molecule in the process leading to RHF and (2) NO is involved in the auxin-signaling cascade leading to RHF. PMID:19521473

  10. Alteration of enod40 expression modifies medicago truncatula root nodule development induced by sinorhizobium meliloti

    Science.gov (United States)

    Charon, C; Sousa, C; Crespi, M; Kondorosi, A

    1999-01-01

    Molecular mechanisms involved in the control of root nodule organogenesis in the plant host are poorly understood. One of the nodulin genes associated with the earliest phases of this developmental program is enod40. We show here that transgenic Medicago truncatula plants overexpressing enod40 exhibit accelerated nodulation induced by Sinorhizobium meliloti. This resulted from increased initiation of primordia, which was accompanied by a proliferation response of the region close to the root tip and enhanced root length. The root cortex of the enod40-transformed plants showed increased sensitivity to nodulation signals. T(1) and T(2) descendants of two transgenic lines with reduced amounts of enod40 transcripts (probably from cosuppression) formed only a few and modified nodulelike structures. Our results suggest that induction of enod40 is a limiting step in primordium formation, and its function is required for appropriate nodule development. PMID:10521525

  11. Calcareous impact on arbuscular mycorrhizal fungus development and on lipid peroxidation in monoxenic roots.

    Science.gov (United States)

    Labidi, Sonia; Calonne, Maryline; Ben Jeddi, Fayçal; Debiane, Djouher; Rezgui, Salah; Laruelle, Frédéric; Tisserant, Benoit; Grandmougin-Ferjani, Anne; Sahraoui, Anissa Lounès-Hadj

    2011-12-01

    The present work underlined the negative effects of increasing CaCO(3) concentrations (5, 10 and 20 mM) both on the chicory root growth and the arbuscular mycorrhizal fungus (AMF) Glomus irregulare development in monoxenic system. CaCO(3) was found to reduce drastically the main stages of G. irregulare life cycle (spore germination, germinative hyphae elongation, root colonization, extraradical hyphae development and sporulation) but not to inhibit it completely. The root colonization drop was confirmed by the decrease in the arbuscular mycorrhizal fungal marker C16:1ω5 amounts in the mycorrhizal chicory roots grown in the presence of CaCO(3). Oxidative damage evaluated by lipid peroxidation increase measured by (i) malondialdehyde (MDA) production and (ii) the antioxidant enzyme peroxidase (POD) activities, was highlighted in chicory roots grown in the presence of CaCO(3). However, MDA formation was significantly higher in non-mycorrhizal roots as compared to mycorrhizal ones. This study pointed out the ability of arbuscular mycorrhizal symbiosis to enhance plant tolerance to high levels of CaCO(3) by preventing lipid peroxidation and so less cell membrane damage.

  12. Multiscale systems analysis of root growth and development: modeling beyond the network and cellular scales.

    Science.gov (United States)

    Band, Leah R; Fozard, John A; Godin, Christophe; Jensen, Oliver E; Pridmore, Tony; Bennett, Malcolm J; King, John R

    2012-10-01

    Over recent decades, we have gained detailed knowledge of many processes involved in root growth and development. However, with this knowledge come increasing complexity and an increasing need for mechanistic modeling to understand how those individual processes interact. One major challenge is in relating genotypes to phenotypes, requiring us to move beyond the network and cellular scales, to use multiscale modeling to predict emergent dynamics at the tissue and organ levels. In this review, we highlight recent developments in multiscale modeling, illustrating how these are generating new mechanistic insights into the regulation of root growth and development. We consider how these models are motivating new biological data analysis and explore directions for future research. This modeling progress will be crucial as we move from a qualitative to an increasingly quantitative understanding of root biology, generating predictive tools that accelerate the development of improved crop varieties.

  13. Negative phototropism of rice root and its influencing factors

    Institute of Scientific and Technical Information of China (English)

    WANG; Zhong(王忠); MO; Yiwei(莫亿伟); QIAN; Shanqin(钱善勤); GU; Yunjie(顾蕴洁)

    2002-01-01

    Some characteristics of the rice (Oryza sativa L.) root were found in the experiment of unilaterally irradiating the roots which were planted in water: (ⅰ) All the seminal roots, adventitious roots and their branched roots bent away from light, and their curvatures ranged from 25° to 60°. The curvature of adventitious root of the higher node was often larger than that of the lower node, and even larger than that of the seminal root. (ⅱ) The negative phototropic bending of the rice root was mainly due to the larger growth increment of root-tip cells of the irradiated side compared with that of the shaded side. (ⅲ) Root cap was the site of light perception. If root cap was shaded while the root was irradiated the root showed no negative phototropism, and the root lost the characteristic of negative phototropism when root cap was divested. Rice root could resume the characteristic of negative phototropism when the new root cap grew up, if the original cells of root cap were well protected while root cap was divested. (ⅳ) The growth increment and curvature of rice root were both influenced by light intensity. Within the range of 0-100μmol@m-2@s-1, the increasing of light intensity resulted in the decreasing of the growth increment and the increasing of the curvature of rice root. (ⅴ) The growth increment and the curvature reached the maximum at 30℃ with the temperature treatment of 10-40℃. (ⅵ) Blue-violet light could prominently induce the negative phototropism of rice root, while red light had no such effect. (ⅶ) The auxin (IAA) in the solution, as a very prominent influencing factor, inhibited the growth, the negative phototropism and the gravitropism of rice root when the concentration of IAA increased. The response of negative phototropism of rice root disappeared when the concentration of IAA was above 10 mg@L-1.

  14. Adventitious shoot regeneration from the leaves of some pear varieties (Pyrus spp.) grown in vitro

    Institute of Scientific and Technical Information of China (English)

    Bharat Kumar POUDYAL; Yuxing ZHANG; Guoqiang DU

    2008-01-01

    The pear (Pyrus spp.) is one of the most important temperate fruit crops. A complete protocol for adventitious shoot regeneration was developed from the leaves of four pear varieties grown in vitro: Abbe Fetel, Yali, Packham's Triumph and Aikansui, and the Chinese rootstock variety Dull. Shoot explants were collected from the field and cultured in vitro in Murashige and acid (IBA). After four weeks, leaf explants of all 5 varieties grown in vitro were excised and cultured in MS cultures were maintained in darkness for 21 days for shoot induction in the shoot induction medium (IM), then transferred to the shoot expression medium (EM) in room at (25±2)℃ under a 16/8 h light/dark photoperiod regime for 8 weeks. Finally, the shoots were transferred to the MS shoot elongation medium (SEM) supplemented gibberellic acid (GA3). A combination of TDZ and NAA had a significant effect on the number of shoot regenera-tions in all 5 tested varieties. The maximum mean number of shoots and maximum number of shoots per leaf obtained from Yali variety were 11.8 (P≤0.001) and 22, followed by Aikansui with 6.6 (P≤0.001) and 4.6, and Duff with 8 (P≤0.001) and 12, all arising from the For Packham's Triumph and Abbe Fetel, the maximum mean number of shoots and maximum number of shoots per leaf were 5.6 (P≤0.001), 4.8 and 8 (P≤0.001), and 11, which produced significantly higher adventitious shoots problems associated with shoot proliferation and regenera-tion were also observed and discussed in this paper.

  15. 灰叶胡杨根蘖繁殖的形态解剖学特征%Morphological and Anatomical Features of Root Sucker Propagation of Populus pruinosa

    Institute of Scientific and Technical Information of China (English)

    李志军; 焦培培; 周正立; 李倩; 李健强

    2012-01-01

    We studied the morpho-anatomic characteristics of the clonal growth of root suckers of Populus pruinosa by the conventional paraffin method. Transverse lateral roots were formed by periderm, secondary vascular tissue, and the tetrarch's primary xylem, with developed vascular rays and secondary elongated parenchyma in secondary vascular tissues. The clonal growth of root suckers of P. Pruinosa is based on the development and growth of adventitious buds on transverse lateral roots. Adventitious buds originated from cork cambium of transverse lateral roots and expressed the time characteristics of synchronous and asynchronous generation and the spatial characteristics of single-point and multi-point gathered generation. The cork cambium cells formed primordia of adventitious buds by cell division. The cell division, proliferation, and differentiation of adventitious primordia formed visible primordia on the surface of transverse lateral roots and directly developed as root suckers. The features of adventitious bud development, distribution, and growth were the key reason for root suckers to keep growing to different sizes and form a densely fasciculate shape. P. Pruinosa has good ability for clonal growth of root suckers.%利用常规石蜡切片法对灰叶胡杨(Populus pruinosa)根蘖繁殖特性进行形态解剖学研究.结果表明:灰叶胡杨横走侧根由周皮、次生维管组织和四原型的初生木质部构成,具有次生维管组织中维管射线、次生韧皮薄壁组织发达的结构特征.灰叶胡杨的根蘖繁殖源于横走侧根上不定芽的发生及生长发育.不定芽起源于横走侧根的木栓形成层,木栓形成层经细胞分裂活动形成不定芽原基,不定芽原基细胞分裂和生长分化形成在横走侧根表面可观察到的不定芽,进而生长发育为根蘖苗.不定芽的发生具有同步或非同步的时间特征和单点或多点聚集的空间分布特点,在生长发育过程中其基部可以产

  16. Use of an in vitro adventitious bud technique for mutation breeding of Begonia x hiemalis

    Energy Technology Data Exchange (ETDEWEB)

    Roest, S.; van Berkel, M.A.E.; Bokelmann, G.S.; Broertjes, C. (Instituut voor Toepassing van Atoomenergie in de Landbouw, Wageningen (Netherlands))

    1981-06-01

    An in vitro propagation of two genotypes of Begonia x hiemalis was achieved through adventitious shoot formation on (sub) cultured leaf-disc explants and subsequent transplantation to soil of explant-parts with adventitious shoots. After irradiation of detached leaves with different doses of X-rays and two cycles of adventitious shoot formation on in vitro (sub) cultured leaf-disc explants, plantlets were produced. About 30% of these plants was mutated with respect to e.g. the colour, size and form of the leaves and flowers. The great majority of the mutants (98.5%) proved to be solid (non-chimeric).

  17. The Roots of Gender Inequality in Developing Countries

    OpenAIRE

    Seema Jayachandran

    2014-01-01

    Is the high degree of gender inequality in developing countries--in education, personal autonomy, and more--explained by underdevelopment itself? Or do the societies that are poor today hold certain cultural views that lead to gender inequality? This article discusses several mechanisms through which, as countries grow, gender gaps narrow. I argue that while much of the GDP/gender-inequality relationship can be explained by the process of development, society-specific factors are also at play...

  18. Association between third mandibular molar impaction and degree of root development in adolescents

    DEFF Research Database (Denmark)

    Lauesen, Søren Rødsgaard; Andreasen, Jens O; Gerds, Thomas Alexander;

    2013-01-01

    of the mandibular third molar region from 132 subjects (71 male and 61 female) from 15 to 20 years of age. Based on the films, 264 lower third molars were classified into an eruption and an impaction group. Root development was recorded according to a quantitative method described by Haavikko (1970......Abstract Objective: To compare the root development and the growth rate of the mandibular third molar (M3 inf) in individuals where the M3 inf erupted vs individuals exhibiting M3 inf impaction. Materials and Methods: Serial standardized intraoral radiographs (Eggen technique) were taken annually......: Delayed mandibular third molar root development is associated with impaction. Radiographs taken at age 15 may predict the risk of impaction and thereby guide decision making for the orthodontist or the oral and maxillofacial surgeon....

  19. Stunted root development: A rare dental complication of Stevens-Johnson syndrome

    Science.gov (United States)

    Sangwan, Aditi; Sangwan, Pankaj; Dahiya, Parveen

    2016-01-01

    Stevens-Johnson syndrome (SJS) is a severe cutaneous reaction seen rarely in clinical practice. Most often, it occurs as an adverse reaction to certain drugs. When it affects children at a very young age, arrested tooth root development may also be seen. We present a case of a 13 year old boy who suffered from SJ syndrome at the age of 7 years. Incomplete root development was observed in all teeth, as demonstrated by panaromic radiography. Clinical features of this condition and its management are further discussed. We aim to emphasise on the need for dental practitioners to be aware of the potential dental complications of SJS and enable them to recognise and manage the condition at the earliest so as to avoid any undesirable sequelae. Key words:Adverse drug reaction, amoxycillin, arrested root development, Stevens-Johnson syndrome. PMID:27703617

  20. Influence of Microgravity Environment on Root Growth, Soluble Sugars, and Starch Concentration of Sweetpotato Stem Cuttings

    Science.gov (United States)

    Mortley, Desmond G.; Bonsi, Conrad K.; Hill, Walter A.; Morris, Carlton E.; Williams, Carol S.; Davis, Ceyla F.; Williams, John W.; Levine, Lanfang H.; Petersen, Barbara V.; Wheeler, Raymond M.

    2009-01-01

    Because sweetpotato [Ipomoea batatas (L.) Lam.] stem cuttings regenerate very easily and quickly, a study of their early growth and development in microgravity could be useful to an understanding of morphological changes that might occur under such conditions for crops that are propagated vegetatively. An experiment was conducted aboard a U.S. Space Shuttle to investigate the impact of microgravity on root growth, distribution of amyloplasts in the root cells, and on the concentration of soluble sugars and starch in the stems of sweetpotatoes. Twelve stem cuttings of ‘Whatley/Loretan’ sweetpotato (5 cm long) with three to four nodes were grown in each of two plant growth units filled with a nutrient agarose medium impregnated with a half-strength Hoagland solution. One plant growth unit was flown on Space Shuttle Colombia for 5 days, whereas the other remained on the ground as a control. The cuttings were received within 2 h postflight and, along with ground controls, processed in ≈45 min. Adventitious roots were counted, measured, and fixed for electron microscopy and stems frozen for starch and sugar assays. Air samples were collected from the headspace of each plant growth unit for postflight determination of carbon dioxide, oxygen, and ethylene levels. All stem cuttings produced adventitious roots and growth was quite vigorous in both ground-based and flight samples and, except for a slight browning of some root tips in the flight samples, all stem cuttings appeared normal. The roots on the flight cuttings tended to grow in random directions. Also, stem cuttings grown in microgravity had more roots and greater total root length than ground-based controls. Amyloplasts in root cap cells of ground-based controls were evenly sedimented toward one end compared with a more random distribution in the flight samples. The concentration of soluble sugars, glucose, fructose, and sucrose and total starch concentration were all substantially greater in the stems of

  1. A comparative histologic study on furcal perforation repair with Root MTA and Pro Root MTA in fully developed teeth in dog

    Directory of Open Access Journals (Sweden)

    Rahimi S.

    2005-07-01

    Full Text Available Background and Aim: The goal of endodontics is to seal the root canal system from the orifice to apical constriction completely and tridimensionally.Hence perforations during root canal therapy, because of caries or resorptions must be sealed and obturated with ideal materials. The aim of this study was to histologically compare two kinds of mineral trioxide aggregate Root MTA and Pro Root MTA for furcal perforation repair in developed teeth in dog. Materials and Methods: In this experimental study, thirty teeth consisting of second, third and fourth mandibular premolars of five German shepherd dogs were selected. Twenty-four teeth were randomly divided into four experimental groups (6 teeth each. One pair of Root MTA and Pro Root MTA groups studied in one month and the other in three months intervals. Positive and negative control groups was each contained three teeth. In positive control group, perforations were not treated and negative control group contained intact teeth. In experimental groups perforations repaired after one week exposure to oral cavity with Root MTA or Pro Root MTA. After time intervals animals were subjected to vital perfusion and 6 m histologic sections were prepared. Inflammation and hard tissue formation were ranked by Cox criteria. Data were analysed using Mann-Whitney and Chi-Square statistical tests with P0.05. Conclusion: Mineral Trioxide Aggregate is an adequate material for furcal perforation repair in dog’s teeth. Root MTA could be a good substitute for Pro Root MTA considering the lower cost and similar characteristics.

  2. Study on Rooting Culture and Rooting Anatomy of Tree Peony 'Wulong Pengsheng' Regenerated Shoots%牡丹‘乌龙捧盛’组培苗生根及生根解剖学研究

    Institute of Scientific and Technical Information of China (English)

    贾文庆; 徐小博; 刘会超; 李纪元

    2013-01-01

    The tissue-cultured seedlings of tree peony ‘ Wulong Pengsheng' were used to study the effects of different plant growth regulators,culture methods,and holdfast on rooting.The morphological structure change during rooting was also observed using the method of paraffin section.The result showed that the best combination of plant growth regulators for rooting was IBA 3.0 mg · L-1 + NAA 0.6 mg · L-1.The treatment under the temperature of 4℃ for ten days was benefit to rooting,and the rate could reach 75.67%.It was identified that the adventitious root primordia of shoot in vitro originated from the vascular cambium cells,especially,the cross areas of cambium and pith ray and they started to differentiate at the 5th day and lasted to the 12th day.If the shoots were cultured in the root inducing medium for 12 days,it would lead to not only descend of rooting rate,but also showing callus of stem base,and leaf senescent.However,if they were transferred into the medium without hormone in time,the root primordial protruded the epidermis and developed normally after 5 days' culture.

  3. Expression profiling of genes involved in ascorbate biosynthesis and recycling during fleshy root development in radish.

    Science.gov (United States)

    Xu, Yao; Zhu, Xianwen; Chen, Yinglong; Gong, Yiqin; Liu, Liwang

    2013-09-01

    Ascorbate is a primary antioxidant and an essential enzyme cofactor in plants, which has an important effect on the development of plant root system. To investigate the molecular mechanisms of ascorbate accumulation during root development and reveal the key genes of the ascorbate biosynthesis and recycling pathways, the expression of 16 related genes together with ascorbate abundance were analyzed in the flesh and skin of radish (Raphanus sativus L.) fleshy root. The content of ascorbate decreased with root growth in both the flesh and skin. Expression of GDP-d-mannose pyrophosphorylase, GDP-d-mannose-3',5'-epimerase and d-galacturonate reductase were also decreased and correlated with ascorbate levels in the flesh. In the skin, the expression of GDP-d-mannose pyrophosphorylase and l-galactose dehydrogenase was correlated with ascorbate levels. These results suggested that ascorbate accumulation is affected mainly by biosynthesis rather than recycling in radish root, and the l-galactose pathway may be the major biosynthetic route of ascorbate, and moreover, the salvage pathway may also contribute to ascorbate accumulation. The data suggested that GDP-d-mannose pyrophosphorylase could play an important role in the regulation of ascorbate accumulation during radish fleshy taproot development.

  4. A Gain-of-Function Mutation in OsIAA11 Affects Lateral Root Development in Rice

    Institute of Scientific and Technical Information of China (English)

    Zhen-Xing Zhu; Yu Liu; Shao-Jun Liu; Chuan-Zao Mao; Yun-Rong Wu; Ping Wu

    2012-01-01

    Lateral roots are important to plants for the uptake of nutrients and water.Several members of the Aux/IAA family have been shown to play crucial roles in lateral root development.Here,a member of the rice Aux/IAA family genes,OsIAA11 (LOC_Os03g43400),was isolated from a rice mutant defective in lateral root development.The gain-of-function mutation in OsIAA 11 strictly blocks the initiation of lateral root primordia,but it does not affect crown root development.The expression of OsIAA11 is defined in root tips,lateral root caps,steles,and lateral root primordia.The auxin reporter DR5-GUS (β-glucuronidase) was expressed at lower levels in the mutant than in wild-type,indicating that OsIAA11 is involved in auxin signaling in root caps.The transcript abundance of both OsPIN1b and OsPIN10a was diminished in root tips of the Osiaa11 mutant.Taken together,the results indicate that the gain-of-function mutation in OsIAA11 caused the inhibition of lateral root development in rice.

  5. Effects of Free-air CO2 Enrichment on Root Characteristics and C:N Ratio of Rice at the Heading Stage

    Institute of Scientific and Technical Information of China (English)

    CHEN Gai-ping; CHENG Lei; ZHU Jian-guo; PANG Jing; XIE Zu-bin; ZENG Qing

    2006-01-01

    A hydroponics experiment was conducted to investigate the rice root growth in FACE (free-air carbon dioxide enrichment). The root biomass, root volume, ratio of root/shoot, number of adventitious roots and root diameter significantly increased under FACE conditions, while the CO2 enrichment decreased the N concentration in rice roots without any change in the C content, leading to an increase in root C:N ratio, Moreover, the elevated CO2 resulted in a remarkable decrease of root activity,expressed as per unit root dry weight, which might be responsible for decreased N concentration in roots.

  6. Transcript and proteomic analysis of developing white lupin (Lupinus albus L. roots

    Directory of Open Access Journals (Sweden)

    Watson Bonnie

    2009-01-01

    Full Text Available Abstract Background White lupin (Lupinus albus L. roots efficiently take up and accumulate (heavy metals, adapt to phosphate deficiency by forming cluster roots, and secrete antimicrobial prenylated isoflavones during development. Genomic and proteomic approaches were applied to identify candidate genes and proteins involved in antimicrobial defense and (heavy metal uptake and translocation. Results A cDNA library was constructed from roots of white lupin seedlings. Eight thousand clones were randomly sequenced and assembled into 2,455 unigenes, which were annotated based on homologous matches in the NCBInr protein database. A reference map of developing white lupin root proteins was established through 2-D gel electrophoresis and peptide mass fingerprinting. High quality peptide mass spectra were obtained for 170 proteins. Microsomal membrane proteins were separated by 1-D gel electrophoresis and identified by LC-MS/MS. A total of 74 proteins were putatively identified by the peptide mass fingerprinting and the LC-MS/MS methods. Genomic and proteomic analyses identified candidate genes and proteins encoding metal binding and/or transport proteins, transcription factors, ABC transporters and phenylpropanoid biosynthetic enzymes. Conclusion The combined EST and protein datasets will facilitate the understanding of white lupin's response to biotic and abiotic stresses and its utility for phytoremediation. The root ESTs provided 82 perfect simple sequence repeat (SSR markers with potential utility in breeding white lupin for enhanced agronomic traits.

  7. Matrix metalloproteinase inhibition reduces adventitial thickening and collagen accumulation following balloon dilation

    NARCIS (Netherlands)

    Sierevogel, MJ; Velema, E; van der Meer, FJ; Nijhuis, MO; de Kleijn, DPV; Borst, C; Pasterkamp, G

    2002-01-01

    Objective: Constrictive arterial remodeling following balloon angioplasty has been related to adventitial collagen accumulation and subsequent thickening and can be prevented by matrix ructalloprotemase (MMP) inhibition. Following balloon dilation, we examined the effect of MMP inhibition on colla-e

  8. Adventitial gene transfer of catalase attenuates angiotensin II-induced vascular remodeling.

    Science.gov (United States)

    Liu, Cun-Fei; Zhang, Jia; Shen, Kai; Gao, Ping-Jin; Wang, Hai-Ya; Jin, Xin; Meng, Chao; Fang, Ning-Yuan

    2015-04-01

    Vascular adventitia and adventitia‑derived reactive oxygen species (ROS) contribute to vascular remodeling following vascular injury. A previous ex vivo study in adventitial fibroblasts showed that catalase, one of most important anti‑oxide enzymes, was downregulated by angiotensin II (AngII). The aim of the present study was to investigate whether adventitial gene transfer of catalase affects AngII‑induced vascular remodeling in vivo. Adenoviruses co‑expressing catalase and enhanced green fluorescent protein (eGFP) or expressing eGFP only were applied to the adventitial surface of common carotid arteries of Sprague‑Dawley rats. Alzet minipumps administering AngII (0.75 mg/kg/day) were then implanted subcutaneously for 14 days. Systolic blood pressure and biological parameters of vascular remodeling were measured in each group. Adventitial fibroblasts were cultured and p38 mitogen‑activated protein kinase (MAPK) phosphorylation was measured using western blot analysis. The results showed that adventitial gene transfer of catalase had no effect on AngII‑induced systolic blood pressure elevation. However, catalase adenovirus transfection significantly inhibited AngII‑induced media hypertrophy compared with that of the control virus (Pcatalase transfection significantly attenuated AngII‑induced ROS generation, macrophage infiltration, collagen deposition and adventitial α‑smooth muscle actin expression. Furthermore, catalase transfection significantly inhibited the AngII‑induced increase in p38MAPK phosphorylation. In conclusion, the results of the present study demonstrated that adventitial gene transfer of catalase significantly attenuated AngII‑induced vascular remodeling in rats via inhibition of adventitial p38MAPK phosphorylation.

  9. Formation of Mycorrhizs-like Structures in Cultured Root/Callus of Cathays argyrophylla Chun et Kuang Infected with the Ectomycorrhizal Fungus Cenococcum geophilum Fr.

    Institute of Scientific and Technical Information of China (English)

    Xue Sun; Yu-Hua Li; Lu-Min Vaario

    2006-01-01

    An in vitro system was used for ectomycorrhizal synthesis of Cenococcum geophilum Fr. with Cathaya argyrophylla Chun et Kuang, an endangered species. Calli initiated from stem segments and adventitious roots differentiated from young seedlings were removed and cocultured with Cenococcum geophilum on a modified Murashige-Skoog medium. Fungal hyphae were visible within intercellular spaces of the callus 4 weeks after inoculation, but definite and well-developed Hartig net structures did not form in the calli 8 weeks after inoculation. The typical ectomycorrhizal structures (i.e. hyphal mantle and intracortical Hartig net) were observed in root segments 8 weeks after inoculation. This is the first report of aseptic ectomycorrhizal-like formation/infection between root organ/callus of Cathaya argyrophylla and the ectomycorrhizal fungus Cenococcum geophilum. This culture system is useful for further investigation of mycorrhizal synthesis in Cathaya trees.

  10. Effect of polyvinyl alcohol on in vitro rooting capacity of shoots in pear clones (Pyrus communis L.) of different ploidy

    Science.gov (United States)

    Poor adventitious root formation is a major obstacle in micropropagation. In this study, intense efforts have been made for improvement of rooting procedures for triploid, tetraploid, and mixploid clones of the pear cultivar, 'Fertility', obtained by in vitro colchicine treatment. An efficient roo...

  11. Effect of ion exchange substrate on grass root development and cohesion of sandy soil

    Science.gov (United States)

    Chomczyńska, Mariola; Soldatov, Vladimir; Wasąg, Henryk; Turski, Marcin

    2016-07-01

    The effect of small additions of ion exchange substrate (nutrient carrier) on root development and accompanying ground cohesion (characterized by its penetration resistance) was studied. During two pot experiments Dactylis glomerata L. was grown on sand and its mixture with 1 and 2% (v/v) of ion exchange substrate, respectively. The number and total length of roots were measured during the first test. Penetration resistance was measured with a pentrologger, following the second experiment. After six weeks of growth, number and length of roots in sand mixture with 1 and 2% substrate was greater than in sand-only medium by 211-287 and 273-323%, respectively. At the same time, penetration resistance in series with substrate additions was significantly higher than in control medium at depth of 2.5-7(8) cm, whereas after 12 week of growth, penetration resistance in series with 1 and 2% substrate additions was significantly greater than in control sand at the whole analyzed depth. The highest resistance values in media with substrate additions 2-2.5 times greater than those in sand alone - were observed at depth of 3.5-4.0 cm. Higher resistance of sand-substrate mixtures results from more intensive development of root systems, forming a mesh which binds sand particles. Such media would be less susceptible to erosion.

  12. Induction and regeneration of adventitious shoot from in vitro leaves of Zizyphus jujuba ' Kongfusucui' plantlet%'孔府酥脆'枣试管苗离体叶片不定梢诱导和再生

    Institute of Scientific and Technical Information of China (English)

    孙清荣; 孙洪雁; 周广芳

    2011-01-01

    Using in vitro leaves of Zizyphus jujuba ‘ Kongfusucui’ plantlet as explants, effects of culture method,phytohormone proportion and culture time on induction rate of adventitious shoot from leaves and effects of sucrose concentrations in rooting media on rooting of adventitious shoot were studied. The results show that induction rate of adventitious shoot by two-step culture method ( firstly cultured on medium Ⅰ for four weeks then cultured on medium Ⅱ for three weeks) is significantly higher than that by one-step culture method (cultured continuously on medium Ⅰ for seven weeks). Phytohormone proportion in medium Ⅰ has an obviously influence on induction rate of adventitious shoot, which gradually increases with increasing of TDZ concentration in medium Ⅰ . And adding 1.0 mg · L-1 TDZ in medium Ⅰ leads to induction rate with above 80%. With culture time prolonging ( cultured for 1, 2, 3 or 4 weeks on medium Ⅰ ,respectively), induction rate increases gradually. Sucrose concentration has a significant effect on rooting of adventitious shoot, sucrose with higher concentration (30 g · L-1 ) is beneficial to rooting. According to induction rate and growth status of adventitious shoot, it is determined that optimal culture method of adventitious shoot induction from Z. jujuba ‘ Kongfusucui’ leaves is two-step culture method, that is, leaves firstly cultured on WPM medium containing 1.0 mg · L-1 TDZ and 0.5 mg · L-1 IAA for four weeks, and then cultured on WPM medium containing 0.5 mg · L-1 IAA and 1.0 mg · L-1 GA3 till adventitious shoot produced.%@@ 红枣营养丰富、富含维生素,深受广大消费者喜爱,但由于枣(Zizyphus jujuba Mill.)树在生长过程中经常受到细菌、真菌等病害的危害,制约了红枣的产量.通过品种改良可以获得优良的枣树品种,但由于枣胚败育率高及落花落果严重等因素,导致利用常规杂交育种方法很难达到品种改良的目的.基因工程的外源基

  13. System analysis of microRNAs in the development and aluminium stress responses of the maize root system.

    Science.gov (United States)

    Kong, Xiangpei; Zhang, Maolin; Xu, Xiangbo; Li, Xiaoming; Li, Cuiling; Ding, Zhaojun

    2014-10-01

    MicroRNAs (miRNAs) are a class of regulatory small RNAs (sRNAs) that down-regulate target genes through mRNA cleavage or translational inhibition. miRNA is known to play an important role in the root development and environmental responses in both the Arabidopsis and rice. However, little information is available to form a complete view of miRNAs in the development of the maize root system and Al stress responses in maize. Four sRNA libraries were generated and sequenced from the early developmental stage of primary roots (PRY), the later developmental stage of maize primary roots (PRO), seminal roots (SR) and crown roots (CR). Through integrative analysis, we identified 278 miRNAs (246 conserved and 32 novel ones) and found that the expression patterns of miRNAs differed dramatically in different maize roots. The potential targets of the identified conserved and novel miRNAs were also predicted. In addition, our data showed that CR is more resistant to Al stress compared with PR and SR, and the differentially expressed miRNAs are likely to play significant roles in different roots in response to environmental stress such as Al stress. Here, we demonstrate that the expression patterns of miRNAs are highly diversified in different maize roots. The differentially expressed miRNAs are correlated with both the development and environmental responses in the maize root. This study not only improves our knowledge about the roles of miRNAs in maize root development but also reveals the potential role of miRNAs in the environmental responses of different maize roots.

  14. Involvement of Hydrogen Peroxide Generated by Polyamine Oxidative Degradation in the Development of Lateral Roots in Soybean

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In order to determine whether hydrogen peroxide (H2O2) generated by polyamine oxidative degradation is involved in the development of lateral roots in soybean, the length and the number of lateral roots, the activities of polyamine oxidases and diamine oxidases, and the endogenous free polyamine and H2O2 content were analyzed in soybean (Glycine max (Linn.) Merr.) main roots of 2-d-old seedlings after treatments for 2 d with exogenous β-hydroxyethylhydrazine (an inhibitor of polyamine oxidases), H2O2, putrescine, cyclohexylamine (an inhibitor of spermidine synthase) or N,N'-dimethylthiourea (a scavenger of hydrogen peroxide).β-hydroxyethylhydrazine treatment strongly inhibited the development of lateral roots in soybean seedlings,reduced the activities of polyamine oxidases and diamine oxidases, decreased H2O2 levels, and led to the accumulation of endogenous polyamines in the main roots. The inhibitory effect of β-hydroxyethylhydrazine on root development could be alleviated by exogenously applied 10 μmol/L H2O2 (a major product of polyamine oxidation). Treatment with cyclohexylamine and putrescine promoted root growth slightly, but treatment with cyclohexylamine plus N,N'-dimethylthiourea or putrescine plus N,N'-dimethylthiourea prevented the development of soybean lateral roots. The effects of these treatments on the development of soybean lateral roots were consistent with the changes in endogenous H2O2 levels. These results suggest that the development of soybean lateral roots is associated with the oxidative degradation of polyamines, and that their products,especially H2O2, are likely to play an important role in the growth of soybean lateral roots.

  15. The structure of the endodermis during the development of wheat (Triticum aestivum L. roots

    Directory of Open Access Journals (Sweden)

    Grażyna Grymaszewska

    2014-01-01

    Full Text Available Four stages of development in the process of differentiation of the root endodermis of wheat (Triticum aestivum L. var. Grana are described. The proendodermis cells have a meristematic nature. Their vacuoles accumulated an osmophilic material. In the next stage, Casparian strips arose in the walls of the endodermis. Dictyosomes and ER cisterns were numerous in the protoplasts of these cells. In the following stage, a suberin lamella was deposited over the entire internal surface of the primary cell wall. In the final stage, a secondary cell wall, thickened in the form of a letter U, was formed. In secondary wall simple pits arose. The endodermis of the wheat root developed asynchronously, more quickly over the phloem bundles.

  16. Immunologically related lectins from stems and roots of developing seedlings of Cucurbita ficifolia: purification and some properties of root and stem lectins

    Directory of Open Access Journals (Sweden)

    Irena Lorenc-Kubis

    2014-02-01

    Full Text Available Hemagglutinating activity has been found in acetate extracts from roots and stems of squash seedlings (Cucurbita ficifolia. The hemaglutinating activity changes during seeds germination and seedling development. Dot blot and Western blot techniques have shown that proteins from these vegetative tissues cross-reacted with antibodies raised against endogenous cotyledons lectin CLBa and Con A.Lectins were isolated from stems and roots of 6-day old seedlings by precipitation with ethanol, affinity chromatography on Con A-Sepharose, gel filtration on Bio-gel P100 and separated by electrophoresis on polyacrylamide gel. Three purified lectins (RLA1, RLA2, RLA3 were obtained from roots and four from stems (SLA1, SLA2, SLA3, SLA4. The purified lectins from roots and stems agglutinated all human red blood cells, but sheep erythrocytes were most sensitive to agglutination. The hemagglutination of the root lectins RLA2 and RLA3 was inhibited by a very low concentration of arabinose, while RLA1, of xylose and Ga1NAc. Arabinose and Xylose were also found to be the most effective inhibitors of all stem lectins.

  17. Effects of lime and calcium on root development and nodulation of clovers

    Energy Technology Data Exchange (ETDEWEB)

    Brauer, D.; Ritchey, D.; Belesky, D. [USDA ARS, Booneville, AR (USA). SPA Dale Bumpers Small Farms Research Centre

    2002-07-01

    Acidic soils can reduce the nodulation of forage legumes. Studies with a Gilpin series silt loam (fine loamy, mixed mesic Typic Hapludult) from New, WV, USA were conducted to determine the effects of lime on root development, and to assess effects of soil Ca and pH on nodulation. Liming increased soil pH from 4.8 to 5.3, nodulation, and root growth of white clover (Trifolium repens L., cultivar Huia) 28 d after planting. Seedlings from unlimed soil formed fewer indeterminate and determinate roots. Next, soils were amended with either CaCO{sub 3} or a mixture of CaCO{sub 3} and CaSO{sub 4} to achieve a soil pH of 4.7 to 6.1 and soil Ca of 170 to 680 mg kg{sup -1} soil. There was a strong quadratic relationship between number of nodules per white clover seedling 28 d after planting and soil pH. Another experiment was conducted to determine if these trends were expressed under field conditions. In 1993, field plots were amended with lime or a coal combustion by-product that supplied Ca as CaSO{sub 4} and seeded in 1994 to cool-season grasses. In spring of 1998, plots were drilled with either red (Trifolium pratense, L.) or white clover. The nodules per primary root were determined in May (1998,1999) and August (1998). Number of nodules per primary root was more closely associated with soil pH than soil Ca.

  18. Comparison between Adventitial and Intimal Inflammation of Ruptured and Nonruptured Atherosclerotic Plaques in Human Coronary Arteries

    Directory of Open Access Journals (Sweden)

    Higuchi Maria L.

    2002-01-01

    Full Text Available OBJECTIVE: To verify the possible role of adventitial inflammation in atherosclerotic plaque vulnerability and coronary artery remodelling. METHODS: We compared the mean numbers of lymphocytes in the adventitia and in the plaque of ruptured thrombosed and stable equi-stenotic coronary segments of 34 patients who died due to acute myocardial infarction. We also analysed adventitial microvessels, adventitial fibrosis and the external elastic membrane. RESULTS: In the adventitia, the numbers of lymphocytes and microvessels/mm² were 69.5±88.3 and 60.9± 32.1 in culprit lesions and 16.4 ± 21.1 and 44.3±16.1 in stable lesions (p<0.05; within the plaques, the mean number of lymphocytes was 24±40.8 in culprit lesions and 10.9±13.2 in stable ones (p=0.17. The mean percent area of adventitial fibrosis/cross-sectional area of the vessel was significantly lower in unstable plaques (p<0.001. The confocal images showed holes in the external elastic membrane. CONCLUSION: Unstable plaques exhibit chronic pan-arteritis, accompanied by enlargement, medial thinning, and less fibrosis than in stable lesions, which is compatible with vessel aneurysm. Adventitial inflammation may contribute significantly to atheroma instability.

  19. Effects of relative humidity and root temperature on calcium concentration and tipburn development in lettuce.

    Science.gov (United States)

    Collier, G F; Tibbitts, T W

    1984-03-01

    Growth chamber studies were undertaken with a tipburn-sensitive cultivar of romaine lettuce (Lactuca sativa L. cv. Lobjoits Green Cos) grown under a photosynthetic photon flux density of 320 micromoles s-1 m-2 for 16 hours; light and dark temperatures were 26.0 degrees and 12.5 degrees C, respectively. As the relative humidity (RH) during the light period was decreased from 74% to 51%, growth was retarded, Ca concentration increased, and the onset of tipburn delayed. Decreasing RH during the dark period from 95% to 90% reduced growth and resulted in lower Ca concentrations and earlier tipburn development. Further decreases from 90% to 65% caused no additional change in growth or tipburn response. Root temperatures of 23.5 degrees, compared with 15.0 degrees, slightly increased Ca concentration but induced earlier tipburn development. Ca concentrations were increased and tipburn delayed by humidity conditions which provided large diurnal fluctuations in water potential in the plant and which encouraged root pressure flow during the dark period. Elevated root temperatures did not provide expected increases in Ca accumulation in young leaves.

  20. Smad4-Shh-Nfic signaling cascade-mediated epithelial-mesenchymal interaction is crucial in regulating tooth root development.

    Science.gov (United States)

    Huang, Xiaofeng; Xu, Xun; Bringas, Pablo; Hung, Yee Ping; Chai, Yang

    2010-05-01

    Transforming growth factor beta (TGF-beta)/bone morphogenetic protein (BMP) signaling is crucial for regulating epithelial-mesenchymal interaction during organogenesis, and the canonical Smad pathway-mediated TGF-beta/BMP signaling plays important roles during development and disease. During tooth development, dental epithelial cells, known as Hertwig's epithelial root sheath (HERS), participate in root formation following crown development. However, the functional significance of HERS in regulating root development remains unknown. In this study we investigated the signaling mechanism of Smad4, the common Smad for TGF-beta/BMP signaling, in HERS in regulating root development. Tissue-specific inactivation of Smad4 in HERS results in abnormal enamel and dentin formation in K14-Cre;Smad4(fl/fl) mice. HERS enlarges but cannot elongate to guide root development without Smad4. At the molecular level, Smad4-mediated TGF-beta/BMP signaling is required for Shh expression in HERS and Nfic (nuclear factor Ic) expression in the cranial neural crest (CNC)-derived dental mesenchyme. Nfic is crucial for root development, and loss of Nfic results in a CNC-derived dentin defect similar to the one of K14-Cre;Smad4(fl/fl) mice. Significantly, we show that ectopic Shh induces Nfic expression in dental mesenchyme and partially rescues root development in K14-Cre;Smad4(fl/fl) mice. Taken together, our study has revealed an important signaling mechanism in which TGF-beta/BMP signaling relies on a Smad-dependent mechanism in regulating Nfic expression via Shh signaling to control root development. The interaction between HERS and the CNC-derived dental mesenchyme may guide the size, shape, and number of tooth roots.

  1. The promoting effects of alginate oligosaccharides on root development in Oryza sativa L. mediated by auxin signaling.

    Science.gov (United States)

    Zhang, Yunhong; Yin, Heng; Zhao, Xiaoming; Wang, Wenxia; Du, Yuguang; He, Ailing; Sun, Kegang

    2014-11-26

    Alginate oligosaccharides (AOS), which are marine oligosaccharides, are involved in regulating plant root growth, but the promotion mechanism for AOS remains unclear. Here, AOS (10-80 mg/L) induced the expression of auxin-related gene (OsYUCCA1, OsYUCCA5, OsIAA11 and OsPIN1) in rice (Oryza sativa L.) tissues to accelerate auxin biosynthesis and transport, and reduced indole-3-acetic acid (IAA) oxidase activity in rice roots. These changes resulted in the increase of 37.8% in IAA concentration in rice roots, thereby inducing the expression of root development-related genes, promoting root growth in a dose-dependent manner, which were inhibited by auxin transport inhibitor 2,3,5-triiodo benzoic acid (TIBA) and calcium-chelating agent ethylene glycol bis (2-aminoethyl) tetraacetic acid (EGTA). AOS also induced calcium signaling generation in rice roots. Those results indicated that auxin mediated AOS regulation of root development, and calcium signaling may act mainly in the upstream of auxin in the regulation of AOS on rice root development.

  2. The effect of polar auxin transport on adventitious branches formation in Gracilaria lichenoides in vitro.

    Science.gov (United States)

    Wang, Wenlei; Li, Huanqin; Lin, Xiangzhi; Zhang, Fang; Fang, Baishan; Wang, Zhaokai

    2016-11-01

    Seaweed tissue culture (STC) is an important micropropagation tool that has been applied for strain improvement, micropropagation and genetic engineering. Because the mechanisms associated with STC are poorly understood, its application to these organisms lags far behind that of tissue culture propagation of higher plants. Auxin, calcium (Ca(2+) ) and hydrogen peroxide (H2 O2 ) fluxes all play key roles during plant growth and development. In this study, we therefore measured indole-3-acetic acid, Ca(2+) and H2 O2 fluxes of Gracilaria lichenoides explants during adventitious branches (ABs) formation for the first time using noninvasive micro-test technology. We confirmed that polar auxin transport (PAT) also occurs in the marine red alga G. lichenoides. We additionally found that N-1-naphthylphthalamic acid may suppress auxin efflux via ABCB1 transporters and then inhibit ABs formation from the apical region of G. lichenoides segments. The involvement of Ca(2+) and H2 O2 fluxes in PAT-mediated AB formation in G. lichenoides was also investigated. We propose that complex feedback among Ca(2+) , H2 O2 and auxin signaling and response systems may occur during ABs polar formation in G. lichenoides explants, similar to that in higher plants. Our results provide innovative insights that should aid future elucidation of mechanisms operative during STC.

  3. High Levels of Hemoglobin Promote Carotid Adventitial Vasa Vasorum Neoangiogenesis in Chronic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Maria Vittoria Arcidiacono

    2017-01-01

    Full Text Available Chronic kidney disease (CKD patients, characterized by traditional and nontraditional risk factors, are prone to develop atheromatosis and thus cardiovascular events and mortality. The angiogenesis of the adventitial vasa vasorum (aVV surrounding the carotid has been described as the atheromatosis initiator. Therefore, the aim of the study was to (1 evaluate if the carotid aVV in CKD patients increases in comparison to its physiological value of healthy patients; (2 explore which traditional or nontraditional risk factor including inflammation, bone and mineral metabolism, and anemia could be related to the aVV angiogenesis. CKD patients without previous cardiovascular events (44, stages 3-4; 37, stage 5D and 65 healthy subjects were compared. The carotid aVV and the intima-media thickness (cIMT were evaluated by ultrasound. CKD patients at stages 3-4 showed higher aVV of the right carotid artery even after adjusting for age. Importantly, a multiple linear regression model showed hemoglobin levels > 12.5 g/dL as the factor for an estimated higher aVV of the right carotid artery. In conclusion, the association of hemoglobin with higher aVV could suggest the role of high hemoglobin in the higher incidence of adverse cardiovascular outcomes in CKD patients.

  4. High Levels of Hemoglobin Promote Carotid Adventitial Vasa Vasorum Neoangiogenesis in Chronic Kidney Disease

    Science.gov (United States)

    Martinez-Alonso, Montserrat; Belart, Montserrat; Vilar, Ana; Martín, Marisa; Craver, Lourdes; Betriu, Àngels; Valdivielso, José Manuel; Fernández, Elvira

    2017-01-01

    Chronic kidney disease (CKD) patients, characterized by traditional and nontraditional risk factors, are prone to develop atheromatosis and thus cardiovascular events and mortality. The angiogenesis of the adventitial vasa vasorum (aVV) surrounding the carotid has been described as the atheromatosis initiator. Therefore, the aim of the study was to (1) evaluate if the carotid aVV in CKD patients increases in comparison to its physiological value of healthy patients; (2) explore which traditional or nontraditional risk factor including inflammation, bone and mineral metabolism, and anemia could be related to the aVV angiogenesis. CKD patients without previous cardiovascular events (44, stages 3-4; 37, stage 5D) and 65 healthy subjects were compared. The carotid aVV and the intima-media thickness (cIMT) were evaluated by ultrasound. CKD patients at stages 3-4 showed higher aVV of the right carotid artery even after adjusting for age. Importantly, a multiple linear regression model showed hemoglobin levels > 12.5 g/dL as the factor for an estimated higher aVV of the right carotid artery. In conclusion, the association of hemoglobin with higher aVV could suggest the role of high hemoglobin in the higher incidence of adverse cardiovascular outcomes in CKD patients. PMID:28133420

  5. Auxin modulates the enhanced development of root hairs in Arabidopsis thaliana (L.) Heynh. under elevated CO(2).

    Science.gov (United States)

    Niu, Yaofang; Jin, Chongwei; Jin, Gulei; Zhou, Qingyan; Lin, Xianyong; Tang, Caixian; Zhang, Yongsong

    2011-08-01

    Root hairs may play a critical role in nutrient acquisition of plants grown under elevated CO(2) . This study investigated how elevated CO(2) enhanced the development of root hairs in Arabidopsis thaliana (L.) Heynh. The plants under elevated CO(2) (800 µL L(-1)) had denser and longer root hairs, and more H-positioned cells in root epidermis than those under ambient CO(2) (350 µL L(-1)). The elevated CO(2) increased auxin production in roots. Under elevated CO(2) , application of either 1-naphthoxyacetic acid (1-NOA) or N-1-naphthylphthalamic acid (NPA) blocked the enhanced development of root hairs. The opposite was true when the plants under ambient CO(2) were treated with 1-naphthylacetic acid (NAA), an auxin analogue. Furthermore, the elevated CO(2) did not enhance the development of root hairs in auxin-response mutants, axr1-3, and auxin-transporter mutants, axr4-1, aux1-7 and pin1-1. Both elevated CO(2) and NAA application increased expressions of caprice, triptychon and rho-related protein from plants 2, and decreased expressions of werewolf, GLABRA2, GLABRA3 and the transparent testa glabra 1, genes related to root-hair development, while 1-NOA and NPA application had an opposite effect. Our study suggests that elevated CO(2) enhanced the development of root hairs in Arabidopsis via the well-characterized auxin signalling and transport that modulate the initiation of root hairs and the expression of its specific genes.

  6. The development of Archaeopteris: new evolutionary characters from the structural analysis of an Early Famennian trunk from southeast Morocco.

    Science.gov (United States)

    Meyer-Berthaud, B; Scheckler, S E; Bousquet, J L

    2000-04-01

    A 5 m long trunk of a young Archaeopteris/Callixylon erianum tree from the Late Devonian of Morocco shows new branching patterns for early lignophytes. This progymnosperm tree produces a helical pattern of traces that we infer belonged to reduced, short-lived, primary (apical) branches (type A) as well as two types of adventitious traces (types B and H). We infer that type-B traces supplied branches that initiate close to the site of attachment on the trunk of some, but not all type-A branches in an irregular but nonrandom pattern. Unlike ephemeral type-A branches, those of type B persist and become long-lived, potentially permanent units of the architecture of Archaeopteris trees. Type-H adventitious traces are also short-lived and occur singly or in serial groups, but differ from traces of either type A or B branches by lacking differentiation into a readily identifiable organ category. We interpret type-H traces as supplying latent primordia that could develop into either adventitious roots or shoots depending on extrinsic factors. Our new data suggest that Archaeopteris had a wide range of branch primordium amplitude. Type-B branches compare with axillary lateral branch buds of some Early Carboniferous spermatophytes (Calamopitys) and are a major developmental departure from the strictly apical, pseudomonopodial shoot branching of older aneurophyte progymnosperms. Type-H traces suggest that Archaeopteris trees had some potential for formation of adventitious roots or shoots in response to environmental factors, such as partial burial by overbank sedimentation. Collectively, these novel methods of tree branching may partly explain the extraordinary success and worldwide dominance of Archaeopteris forests on fluvially dominated, Late Devonian floodplains.

  7. Protecting tree roots and subterranean infrastructure in urban areas by developing self-compacting flowable fills with root growth impeding properties

    Science.gov (United States)

    Felde, Vincent; Simon, Jana; Kimm-Friedenberg, Stefan; Peth, Stephan; Middendorf, Bernhard

    2015-04-01

    In urban areas, the installation of cables and disposal lines is still done by open building method. Here, a ditch is being excavated, pipes and lines are laid and subsequently it is filled with and covered by bulk material (e.g. sand or gravel), which is then compacted. Due to the often times limited space that the roots have in the ground and the better supply of water and oxygen in the poorly compacted bulk material, these refilled ditches are areas of preferential root growth of urban trees. The entangling of the pipes and supply lines by these roots leads to severe damage of the tree when maintenance work on the lines is carried out and roots have to be cut. In order to reduce this competition between urban trees and urban subterranean infrastructure, the development of a self-compacting flowable fill with root growth resistance is mandatory. Physico-chemical properties, such as a very high pH-value and a low cation-exchange-capacity, a low root-penetrability, a high packing density and a low porosity, with a poorly connected pore system that impedes gas and water exchange are the characteristic aspects of this flowable fills that could help avoid undesired root penetration into supply lines. The flowable fills are supposed to sheath pipes and lines void-free and without any tension, in order to restrain the root growth in these areas. Trees are of crucial importance for urban ecosystems and are comprising 3% of the total stock of trees in the Federal Republic of Germany, which is why it is fundamental to conserve them. This work therefore targets not only at enabling a balanced coexistence of urban trees and subterranean infrastructure, but also at avoiding costly re-opening of ditches, tree harming cutting of roots and time consuming maintenance work. Further positive side effects are reduced costs for network providers and local municipalities, as well as reduced noise and dust emissions for passersby and local residents. To guarantee the root growth

  8. Adventitial cystic disease of the left external iliac vein: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Sang Hee; Shin, Hyun Woong; Lee, Yil Gi; Koo, Mi Jin [Daegu Fatima Hospital, Daegu (Korea, Republic of)

    2005-10-15

    Adventitial cystic disease (ACD) is a rare, but well-characterized vascular disease. It is most commonly seen in the popliteal artery, but it has also been reported in the venous system. The most commonly involved segment has been the common femoral vein; the disease resulted in luminal compromise and extremity swelling. We report here on a case of adventitial cystic disease of the left external iliac vein that was initially misdiagnosed as deep vein thrombosis in a 68-years-old man who presented with a painless swelling of his left leg.

  9. Bone morphogenetic protein-2 gene controls tooth root development in coordination with formation of the periodontium

    Institute of Scientific and Technical Information of China (English)

    Audrey Rakian; Wu-Chen Yang; Jelica Gluhak-Heinrich; Yong Cui; Marie A Harris; Demitri Villarreal; Jerry Q Feng; Mary MacDougall; Stephen E Harris

    2013-01-01

    Formation of the periodontium begins following onset of tooth-root formation in a coordinated manner after birth. Dental follicle progenitor cells are thought to form the cementum, alveolar bone and Sharpey’s fibers of the periodontal ligament (PDL). However, little is known about the regulatory morphogens that control differentiation and function of these progenitor cells, as well as the progenitor cells involved in crown and root formation. We investigated the role of bone morphogenetic protein-2 (Bmp2) in these processes by the conditional removal of the Bmp2 gene using the Sp7-Cre-EGFP mouse model. Sp7-Cre-EGFP first becomes active at E18 in the first molar, with robust Cre activity at postnatal day 0 (P0), followed by Cre activity in the second molar, which occurs after P0. There is robust Cre activity in the periodontium and third molars by 2 weeks of age. When the Bmp2 gene is removed from Sp71 (Osterix1) cells, major defects are noted in root, cellular cementum and periodontium formation. First, there are major cell autonomous defects in root-odontoblast terminal differentiation. Second, there are major alterations in formation of the PDLs and cellular cementum, correlated with decreased nuclear factor IC (Nfic), periostin and a-SMA1 cells. Third, there is a failure to produce vascular endothelial growth factor A (VEGF-A) in the periodontium and the pulp leading to decreased formation of the microvascular and associated candidate stem cells in the Bmp2-cKOSp7-Cre-EGFP. Fourth, ameloblast function and enamel formation are indirectly altered in the Bmp2-cKOSp7-Cre-EGFP. These data demonstrate that the Bmp2 gene has complex roles in postnatal tooth development and periodontium formation.

  10. Novel cotton homeobox gene and its expression profiling in root development and in response to stresses and phytohormones

    Institute of Scientific and Technical Information of China (English)

    Yongxiang Ni; Xiulan Wang; Dengdi Li; Yajie Wu; Wenliang Xu; Xuebao Li

    2008-01-01

    Homeodomain-leucine zipper (HD-Zip) proteins are transcriptional factors involved in plant development.In this study,one cDNA clone (Gossypium hirsutum homeobox1,designated GhHB1) encoding HD-Zip protein was isolated from a cotton root cDNA library.The GhHB1 cDNA is 1132 bp in length,including an 828 bp open reading frame that encodes a peptide with 275 amino acids,and 5'-/3'- untranslated regions.The predicted GhHB1 protein containing a homeodomain and a leucine-rich zipper motif shares relatively high identity with other plant HD-Zip proteins.Analysis using quantitative real-time RT-PCR indicated that the GhHB1 gene is predominantly expressed in roots and hypocotyls.Furthermore,GhHB1 transcripts were largely accumulated in early root development,and significantly reduced to very low levels as roots further developed,suggesting that the gene might function in the early development of roots.Under treatment with 1% NaCl,the expression level of the GhHB1 gene was dramatically increased in roots.Likewise,GhHB1 activity in roots was up-regulated by abscisic acid.These results imply that GhHB1 might play an important role in response to salt stress and to abscisic acid signaling.

  11. Clinical Results of Carotid Denervation by Adventitial Stripping in Carotid Sinus Syndrome

    NARCIS (Netherlands)

    Toorop, R. J.; Scheltinga, M. R.; Huige, M. C.; Moll, F. L.

    2010-01-01

    Aims: Older patients with spells of syncope may suffer from a carotid sinus syndrome (CSS). Patients with invalidating CSS routinely receive pacemaker treatment. This study evaluated the safety and early outcome of a surgical technique termed carotid denervation by adventitial stripping for CSS trea

  12. Tissue sealing device associated thermal spread: a comparison of histologic methods for detecting adventitial collagen denaturation

    Science.gov (United States)

    Jones, Ryan M.; Grisez, Brian T.; Thomas, Aaron C.; Livengood, Ryan H.; Coad, James E.

    2013-02-01

    Thermal spread (thermal tissue damage) results from heat conduction through the tissues immediately adjacent to a hyperthermic tissue sealing device. The extent of such heat conduction can be assessed by the detection of adventitial collagen denaturation. Several histologic methods have been reported to measure adventitial collagen denaturation as a marker of thermal spread. This study compared hematoxylin and eosin staining, Gomori trichrome staining and loss of collagen birefringence for the detection of collagen denaturation. Twenty-eight ex vivo porcine carotid arteries were sealed with a commercially available, FDA-approved tissue sealing device. Following formalin fixation and paraffin embedding, two 5-micron tissue sections were hematoxylin and eosin and Gomori trichrome stained. The hematoxylin and eosin-stained section was evaluated by routine bright field microscopy and under polarized light. The trichromestained section was evaluated by routine bright field microscopy. Radial and midline adventitial collagen denaturation measurements were made for both the top and bottom jaw sides of each seal. The adventitial collagen denaturation lengths were determined using these three methods and statistically compared. The results showed that thermal spread, as represented by histologically detected collagen denaturation, is technique dependent. In this study, the trichrome staining method detected significantly less thermal spread than the hematoxylin and eosin staining and birefringence methods. Of the three methods, hematoxylin and eosin staining provided the most representative results for true thermal spread along the adjacent artery.

  13. Genetic basis of cytokinin and auxin functions during root nodule development

    Directory of Open Access Journals (Sweden)

    Takuya eSuzaki

    2013-03-01

    Full Text Available The phytohormones cytokinin and auxin are essential for the control of diverse aspects of cell proliferation and differentiation processes in plants. Although both phytohormones have been suggested to play key roles in the regulation of root nodule development, only recently, significant progress has been made in the elucidation of the molecular genetic basis of cytokinin action in the model leguminous species, Lotus japonicus and Medicago truncatula. Identification and functional analyses of the putative cytokinin receptors LOTUS HISTIDINE KINASE 1 and M. truncatula CYTOKININ RESPONSE 1 have brought a greater understanding of how activation of cytokinin signaling is crucial to the initiation of nodule primordia. Recent studies have also started to shed light on the roles of auxin in the regulation of nodule development. Here, we review the history and recent progress of research into the roles of cytokinin and auxin, and their possible interactions, in nodule development.

  14. The influence of protein-calorie malnutrition on the development of paranodal regions in spinal roots. A study with the OTAN method on rat.

    Science.gov (United States)

    Nordborg, C

    1977-11-28

    During the early postnatal development of spinal roots in rats paranodal regions were often found, containing OTAN-positive inclusions in the Schwann cell cytoplasm. The presence of OTAN-positive paranodal regions showed variations in time, which were synchronous for ventral and dorsal roots. Dorsal roots, however, showed a more marked presence during development than ventral roots. Spinal roots of animals submitted to a 50% food restriction, were shown to contain more OTAN-positive paranodal regions than controls. This was true for ventral as well as dorsal roots. It is suggested that crowding of internodal segments could be one factor, determining the presence of paranodal, OTAN-positive material.

  15. Development Policy in Thailand: From Top-down to Grass Roots.

    Science.gov (United States)

    Kelly, Matthew; Yutthaphonphinit, Phattaraphon; Seubsman, Sam-Ang; Sleigh, Adrian

    2012-11-01

    Top-down industrial development strategies initially dominated the developing world after the second World War but were eventually found to produce inequitable economic growth. For a decade or more, governments and international development agencies have embraced the idea of participatory grass roots development as a potential solution. Here we review Thailand's experience with development strategies and we examine the current focus on participatory approaches. Thai government planning agencies have adopted "people centred development" and a "sufficiency economy", particularly emphasised since the disruptions caused by the 1997 Asian financial crisis. They aim to address the inequitable sharing of the benefits of decades of rapid growth that was particularly unfair for the rural poor. Thai policies aim to decentralise power to the local level, allowing civil society and Non-Governmental Organisations (NGOs) more of a voice in national decision making and promoting sustainable farming practices aimed at enriching rural communities. An example of this change in Thai government policy is the Community Worker Accreditation Scheme which is aiming to develop human resources at the local level by training community based leaders and supporting networks of community organisations. This enables autonomous local development projects led by trained and accredited individuals and groups. The political tensions notable in Thailand at present are part of this modern transition driven by conflicting models of top-down (industrial) development and the bottom-up (participatory) development ideals described above. Once resolved, Thailand will have few obstacles to moving to a new economic level.

  16. Infection of Cultured Thin Cell Layer Roots of Lycopersicon esculentum by Meloidogyne incognita

    OpenAIRE

    Radin, D. N.; Eisenback, J. D.

    1991-01-01

    A new aseptic culture system for studying interactions between tomato (Lycopersicon esculentum) and Meloidogyne incognita is described. Epidermal thin cell layer explants from peduncles of tomato produced up to 20 adventitious roots per culture in 4-9 days on Murashige &Scoog medium plus kinetin and indole acetic acid. Rooted cultures were transferred to Gamborg's B-5 medium and inoculated with infective second-stage juveniles. Gall formation was apparent 5 days after inoculation and egg prod...

  17. An adventitial IL-6/MCP1 amplification loop accelerates macrophage-mediated vascular inflammation leading to aortic dissection in mice

    Science.gov (United States)

    Tieu, Brian C.; Lee, Chang; Sun, Hong; LeJeune, Wanda; Recinos, Adrian; Ju, Xiaoxi; Spratt, Heidi; Guo, Dong-Chuan; Milewicz, Dianna; Tilton, Ronald G.; Brasier, Allan R.

    2009-01-01

    Vascular inflammation contributes to cardiovascular diseases such as aortic aneurysm and dissection. However, the precise inflammatory pathways involved have not been clearly defined. We have shown here that subcutaneous infusion of Ang II, a vasopressor known to promote vascular inflammation, into older C57BL/6J mice induced aortic production of the proinflammatory cytokine IL-6 and the monocyte chemoattractant MCP-1. Production of these factors occurred predominantly in the tunica adventitia, along with macrophage recruitment, adventitial expansion, and development of thoracic and suprarenal aortic dissections. In contrast, a reduced incidence of dissections was observed after Ang II infusion into mice lacking either IL-6 or the MCP-1 receptor CCR2. Further analysis revealed that Ang II induced CCR2+CD14hiCD11bhiF4/80– macrophage accumulation selectively in aortic dissections and not in aortas from Il6–/– mice. Adoptive transfer of Ccr2+/+ monocytes into Ccr2–/– mice resulted in selective monocyte uptake into the ascending and suprarenal aorta in regions of enhanced ROS stress, with restoration of IL-6 secretion and increased incidence of dissection. In vitro, coculture of monocytes and aortic adventitial fibroblasts produced MCP-1– and IL-6–enriched conditioned medium that promoted differentiation of monocytes into macrophages, induced CD14 and CD11b upregulation, and induced MCP-1 and MMP-9 expression. These results suggest that leukocyte-fibroblast interactions in the aortic adventitia potentiate IL-6 production, inducing local monocyte recruitment and activation, thereby promoting MCP-1 secretion, vascular inflammation, ECM remodeling, and aortic destabilization. PMID:19920349

  18. Genes of the most conserved WOX clade in plants affect root and flower development in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Moreau Hervé

    2008-10-01

    Full Text Available Abstract Background The Wuschel related homeobox (WOX family proteins are key regulators implicated in the determination of cell fate in plants by preventing cell differentiation. A recent WOX phylogeny, based on WOX homeodomains, showed that all of the Physcomitrella patens and Selaginella moellendorffii WOX proteins clustered into a single orthologous group. We hypothesized that members of this group might preferentially share a significant part of their function in phylogenetically distant organisms. Hence, we first validated the limits of the WOX13 orthologous group (WOX13 OG using the occurrence of other clade specific signatures and conserved intron insertion sites. Secondly, a functional analysis using expression data and mutants was undertaken. Results The WOX13 OG contained the most conserved plant WOX proteins including the only WOX detected in the highly proliferating basal unicellular and photosynthetic organism Ostreococcus tauri. A large expansion of the WOX family was observed after the separation of mosses from other land plants and before monocots and dicots have arisen. In Arabidopsis thaliana, AtWOX13 was dynamically expressed during primary and lateral root initiation and development, in gynoecium and during embryo development. AtWOX13 appeared to affect the floral transition. An intriguing clade, represented by the functional AtWOX14 gene inside the WOX13 OG, was only found in the Brassicaceae. Compared to AtWOX13, the gene expression profile of AtWOX14 was restricted to the early stages of lateral root formation and specific to developing anthers. A mutational insertion upstream of the AtWOX14 homeodomain sequence led to abnormal root development, a delay in the floral transition and premature anther differentiation. Conclusion Our data provide evidence in favor of the WOX13 OG as the clade containing the most conserved WOX genes and established a functional link to organ initiation and development in Arabidopsis, most

  19. Influence of lead on the development of lupin seedlings and ultrastructural localization of this metal in the roots

    Directory of Open Access Journals (Sweden)

    Adam Woźny

    2014-02-01

    Full Text Available The effect of lead on the early phases of development of yellow lupin seedlings was investigated. In the presence of this metal the number of germinating seeds was found to diminish distinctly, the hypocotyls and roots were shorter and the fresh weight and anthocyanin content in the cotyledones were markedly decreased. In the root cap cells lead was present in the vacuoles, ER, dictyosomes, the nuclear envelope and cell walls.

  20. Root development of non-accumulating and hyperaccumulating plants in metal-contaminated soils amended with biochar.

    Science.gov (United States)

    Rees, Frédéric; Sterckeman, Thibault; Morel, Jean Louis

    2016-01-01

    Biochar may be used as an amendment in contaminated soils in phytoremediation processes. The mechanisms controlling plant metal uptake in biochar-amended soils remain however unclear. This work aimed at evaluating the influence of biochar on root development and its consequence on plant metal uptake, for two non-hyperaccumulating plants (Zea mays and Lolium perenne) and one hyperaccumulator of Cd and Zn (Noccaea caerulescens). We conducted rhizobox experiments using one acidic and one alkaline soil contaminated with Cd, Pb and Zn. Biochar was present either homogeneously in the whole soil profile or localized in specific zones. A phenomenon of root proliferation specific to biochar-amended zones was seen on the heterogeneous profiles of the acidic soil and interpreted by a decrease of soil phytotoxicity in these zones. Biochar amendments also favored root growth in the alkaline soil as a result of the lower availability of certain nutrients in the amended soil. This increase of root surface led to a higher accumulation of metals in roots of Z.mays in the acidic soil and in shoots of N. caerulescens in the alkaline soil. In conclusion, biochar can have antagonist effects on plant metal uptake by decreasing metal availability, on one hand, and by increasing root surface and inducing root proliferation, on the other hand.

  1. Effects of different drought treatments on root and shoot development of the tomato wild type and flacca mutant

    Directory of Open Access Journals (Sweden)

    Prokić Ljiljana

    2011-01-01

    Full Text Available The effects of drought and partial root drying (PRD on shoot and root growth was assessed in the wild type Ailsa Craig (WT and the flacca tomato mutant deficient in the plant hormone ABA. Our results show that drought had an inhibitory effect on shoot growth in flacca and especially in WT; the most profound effect was observed in FI (full irrigation, then PRD and the smallest in D plants. Root development in both WT and flacca was stimulated after the 3rd day of the experiment following a decrease in the soil water content. On the 11th day of the experiment, when the soil water content was reduced by about 50% of full irrigation (FI, the root density was increased in the drying part of the PDR and on both sides of the drought treatment. On the basis of these results it can be assumed that increased root density and root length represent an adaptation or root adjustment to drought conditions.

  2. The structure of the endodermis during the development of pea (Pisum sativum L. roots

    Directory of Open Access Journals (Sweden)

    Joanna Kopcińska

    2014-02-01

    Full Text Available It is shown on the basis of cytological studies that during the development of the pea root endodermis, the following structures were formed (in order of appearance: proendodermis, Casparian strips, suberin lamellae and secondary cell walls. The proendodermis cells had, in addition to the commonly occurring cell components, small vacuoles filled with phenols. The Casparian strips developed in the radial walls and accounted for no more than 1/3 of their length. The suberin layer, found on all of the endodermis walls, was deposited last over the Casparian strips. The secondary cell wall was formed only in the cells located over the phloem bundles. Its thickness was uniform over the entire circumference of the cell.

  3. Cell identity regulators link development and stress responses in the Arabidopsis root.

    Science.gov (United States)

    Iyer-Pascuzzi, Anjali S; Jackson, Terry; Cui, Hongchang; Petricka, Jalean J; Busch, Wolfgang; Tsukagoshi, Hironaka; Benfey, Philip N

    2011-10-18

    Stress responses in plants are tightly coordinated with developmental processes, but interaction of these pathways is poorly understood. We used genome-wide assays at high spatiotemporal resolution to understand the processes that link development and stress in the Arabidopsis root. Our meta-analysis finds little evidence for a universal stress response. However, common stress responses appear to exist with many showing cell type specificity. Common stress responses may be mediated by cell identity regulators because mutations in these genes resulted in altered responses to stress. Evidence for a direct role for cell identity regulators came from genome-wide binding profiling of the key regulator SCARECROW, which showed binding to regulatory regions of stress-responsive genes. Coexpression in response to stress was used to identify genes involved in specific developmental processes. These results reveal surprising linkages between stress and development at cellular resolution, and show the power of multiple genome-wide data sets to elucidate biological processes.

  4. Development of a novel AMX-loaded PLGA/zein microsphere for root canal disinfection

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, F F O [Capes Foundation, Ministry of Education of Brazil, Cx. Postal 365, BrasIlia DF 70359-970 (Brazil); Luzardo-Alvarez, A; Blanco-Mendez, J [Department of Pharmacy and Pharmaceutical Technology, School of Pharmacy, University of Santiago de Compostela, Campus Universitario Sur s/n, 15782, Santiago de Compostela (Spain); Perez-Estevez, A; Seoane-Prado, R, E-mail: franciscofabio.oliveira@rai.usc.e [Departament of Microbiology and Parasitology, Medical School, University of Santiago de Compostela, R/de San Francisco, s/n, 15782, Santiago de Compostela (Spain)

    2010-10-01

    The aim of this study was to develop polymeric biodegradable microspheres (MSs) of poly(d-l lactide-co-glycolide) (PLGA) and zein capable of delivering amoxicillin (AMX) at significant levels for root canal disinfection. PLGA/zein MSs were prepared using a spray-drying technique. The systems were characterized in terms of particle size, morphology, drug loading and in vitro release. Drug levels were reached to be effective during the intracanal dressing in between visits during the endodontic treatment. In vitro release studies were carried out to understand the release profile of the MSs. Antimicrobial activity of AMX was performed by antibiograms. Enterococcus faecalis was the bacteria selected due to its prevalence in endodontic failure. Drug microencapsulation yielded MSs with spherical morphology and an average particle size of between 5 and 38 {mu}m. Different drug-release patterns were obtained among the formulations. Release features related to the MSs were strongly dependent on drug nature as it was demonstrated by using a hydrophobic drug (indomethacin). Finally, AMX-loaded MSs were efficient against E faecalis as demonstrated by the antibiogram results. In conclusion, PLGA/zein MSs prepared by spray drying may be a useful drug delivery system for root canal disinfection.

  5. Histological features, starch accumulation and sprouting in the early root development of Jacaranda ulei (Bignoniaceae

    Directory of Open Access Journals (Sweden)

    PAULO R.D. DA SILVA

    2014-03-01

    Full Text Available The plant species occurring in the savanna region of the Cerrado biome in Brazil present typical morphological and physiological adaptations to a dry climate with seasonal occurrence of wildfires. In this study, the histological features of the root system, the main sites of synthesis and storage of starch and the initial phases of the bud development were characterized in Jacaranda ulei. The anatomical features observed in the root system of J. ulei are related to the needs of the species to survive in the Cerrado. The histochemical analyses demonstrated high synthesis of glucose and glycoprotein after the third day of in vitro culture, in the proximal cells of the cortical parenchyma of the exoderm. Meristematic primordia were observed in the ninth day and the beginning of the meristem formation was observed after 21 days of in vitro culture. Jacaranda ulei displays morphological, anatomical and storage features typical from resprouter species. However, it may be vulnerable to unsustainable exploitation. Considering the importance of this species for local people, more studies regarding its therapeutic properties should be performed, including the planning of appropriate programs for the species management and the production of selected clones through in vitro micropropagation.

  6. Tree roots — Methodological review and new development in dating and quantifying erosive processes

    Science.gov (United States)

    Gärtner, Holger

    2007-05-01

    Exposed roots have been used in Dendrogeomorphology since the 1960s to determine erosion rates. This was done by using the root axis as the relative position of the former soil layer and then relating this measure to the age of the root in order to quantify the amount of soil erosion over time. Recently, wood anatomical research revealed the possibility of determining the first year of exposure of roots due to specific anatomical changes within the respective annual ring. As a consequence, using exposed roots that are still in contact to the soil surface, it is possible to reconstruct the size and position of the root at the time of exposure. Consequently, a new equation is presented to calculate the thickness of the eroded soil layer allowing a detailed reconstruction of erosion rates. The technique also helps to determine if the root was exposed by erosional processes or just by its ongoing secondary growth without any erosion involved.

  7. Hydrogen Sulfide Promotes Root Organogenesis in Ipomoea batatas, Salix matsudana and Glycine max

    Institute of Scientific and Technical Information of China (English)

    Hua Zhang; Jun Tang; Xiao-Ping Liu; Yun Wang; Wei Yu; Wei-Yan Peng; Fang Fang; Dai-Fu Ma; Zhao-Jun Wei; Lan-Ying Hu

    2009-01-01

    In this report, we demonstrate that sodium hydrosulfide (NaHS), a hydrogen sulfide (H2S) donor, promoted adventitious root formation mediated by auxin and nitric oxide (NO). Application of the H2S donor to seedling cuttings of sweet potato (Ipomoea batatas L.) promoted the number and length of adventltious roots in a dose-dependent manner. It was also verified that H2S or HS- rather than other sulfur-containing components derived from NariS could be attributed to the stimulation of adventitious root formation. A rapid Increase In endogenous H2S, indole acetic acid (IAA) and NO were sequentially observed in shoot tips of sweet potato seedlings treated with HallS. Further investigation showed that HzS-mediated root formation was alleviated by N-l-naphthylphthalamic acid (NPA), an IAA transport inhibitor, and 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO), an NO scavenger. Similar phenomena in H2S donor-dependent root organogenesis were observed in both excised willow (Sallx matsudana var. tortuosa Vilm) shoots and soybean (Glycine max L.) seedlings. These results indicated that the process of H2S-induced adventitious root formation was likely mediated by IAA and NO, and that H2S acts upstream of IAA and NO signal transduction pathways.

  8. Architecture of infection thread networks in developing root nodules induced by the symbiotic bacterium Sinorhizobium meliloti on Medicago truncatula.

    Science.gov (United States)

    Monahan-Giovanelli, Hannah; Pinedo, Catalina Arango; Gage, Daniel J

    2006-02-01

    During the course of the development of nitrogen-fixing root nodules induced by Sinorhizobium meliloti on the model plant Medicago truncatula, tubules called infection threads are cooperatively constructed to deliver the bacterial symbiont from the root surface to cells in the interior of the root and developing nodule. Three-dimensional reconstructions of infection threads inside M. truncatula nodules showed that the threads formed relatively simple, tree-like networks. Some characteristics of thread networks, such as branch length, branch density, and branch surface-to-volume ratios, were remarkably constant across nodules in different stages of development. The overall direction of growth of the networks changed as nodules developed. In 5-d-old nodules, the overall growth of the network was directed inward toward the root. However, well-defined regions of these young networks displayed an outward growth bias, indicating that they were likely in the process of repolarizing their direction of development in response to the formation of the outward-growing nodule meristem. In 10- and 30-d-old nodules, the branches of the network grew outward toward the meristem and away from the roots on which the nodules developed.

  9. [Effects of water stress and nitrogen fertilization on peanut root morphological development and leaf physiological activities].

    Science.gov (United States)

    Ding, Hong; Zhang, Zhi-meng; Dai, Liang-xiang; Ci, Dun-wei; Qin, Fei-fei; Song, Wen-wu; Liu, Meng-juan; Fu, Xiao

    2015-02-01

    Taking 'Huayu 22' peanut as test material, effect of soil water content and nitrogen fertilization on the leaf physiological activities and root morphological characteristics of peanut plants were analyzed. Two levels of soil water condition were: (1) well-watered condition and (2) moderate water stress, and three levels of nitrogen were: (1) none nitrogen (N0), (2) moderate nitrogen (N1, 90 kg · hm(-2)) and (3) high nitrogen (N2, 180 kg · hm(-2)). The results showed that N1 significantly increased the peanut yield under two water conditions, but showed no significant effect on harvest index compared with N0. Under water stress condition, N1 had no significant effects on total root biomass and total root length, but the total root surface area was remarkably increased. The nitrogen fertilization significantly increased the root length and root surface area in 20-40 cm soil layer, and N2 significantly increased the root biomass and root surface area in the soil layer below 40 cm. The application of nitrogen remarkably increased CAT and POD activities in leaf, while MDA content was decreased with the increase of nitrogen level. Under well-watered condition, the root biomass, root length and root surface area in the soil layer below 40 cm and total root surface area were significantly reduced by nitrogen application, however, only N1 could increase leaf protective enzyme activities. Correlation analysis showed that the root length in 20-40 cm soil layer and SOD, CAT, POD activities in leaf were highly significantly related with peanut yield.

  10. The inter-kingdom volatile signal indole promotes root development by interfering with auxin signalling.

    Science.gov (United States)

    Bailly, Aurélien; Groenhagen, Ulrike; Schulz, Stefan; Geisler, Markus; Eberl, Leo; Weisskopf, Laure

    2014-12-01

    Recently, emission of volatile organic compounds (VOCs) has emerged as a mode of communication between bacteria and plants. Although some bacterial VOCs that promote plant growth have been identified, their underlying mechanism of action is unknown. Here we demonstrate that indole, which was identified using a screen for Arabidopsis growth promotion by VOCs from soil-borne bacteria, is a potent plant-growth modulator. Its prominent role in increasing the plant secondary root network is mediated by interfering with the auxin-signalling machinery. Using auxin reporter lines and classic auxin physiological and transport assays we show that the indole signal invades the plant body, reaches zones of auxin activity and acts in a polar auxin transport-dependent bimodal mechanism to trigger differential cellular auxin responses. Our results suggest that indole, beyond its importance as a bacterial signal molecule, can serve as a remote messenger to manipulate plant growth and development.

  11. The novel expression of Oct3/4 and Bmi1 in the root development of mouse molars.

    Science.gov (United States)

    Nakagawa, Eizo; Zhang, Li; Shin, Jeong-Oh; Kim, Eun-Jung; Cho, Sung-Won; Ohshima, Hayato; Chen, Zhi; Jung, Han-Sung

    2012-02-01

    The root apex of the tooth elongates until the completion of root development. Although the signaling molecules inducing root elongation have been studied, the characteristic of the cells having the ability to maintain the root elongation remains unclear. This study aimed to investigate the characteristics of the cells involved in the root elongation. Octamer-binding factor 3/4 (Oct3/4) is known as one of the key regulators in maintaining the pluripotency and self-renewal properties of embryonic stem cells. Bmi1, the polycomb-group transcriptional repressor, has emerged as a key regulator in several cellular processes including stem cell self-renewal and cancer cell proliferation. At the beginning of root formation, ameloblasts expressed Oct3/4 in the nucleus, except in the apex of the cervical loop, in which Bmi1and cyclinD were expressed. At PN6, the expression of Oct3/4 in the ameloblasts shifted from the nucleus to the cytoplasm, whereas ameloblastin-negative Hertwig's epithelial root sheath (HERS) cells expressed Bmi1 and cyclinD. By PN10, the cells in the apex of HERS began to express Oct3/4 in their nucleus, whereas Bmi1 and cyclinD began to decrease in their expressions. The odontoblasts consistently expressed Oct3/4 in their cytoplasm. Our results suggest that (1) Oct3/4 creates the border between the ameloblasts from the proliferative region of HERS, (2) Bmi1-positive cells would be one of the candidates resulting in root elongation and (3) the Oct3/4 expression in the cytoplasm of odontoblasts may be related to maintain the odontoblastic characteristics.

  12. Leaf proteomic analysis in cassava (Manihot esculenta, Crantz) during plant development, from planting of stem cutting to storage root formation.

    Science.gov (United States)

    Mitprasat, Mashamon; Roytrakul, Sittiruk; Jiemsup, Surasak; Boonseng, Opas; Yokthongwattana, Kittisak

    2011-06-01

    Tuberization in cassava (Manihot esculenta Crantz) occurs simultaneously with plant development, suggesting competition of photoassimilate partitioning between the shoot and the root organs. In potato, which is the most widely studied tuber crop, there is ample evidence suggesting that metabolism and regulatory processes in leaf may have an impact on tuber formation. To search for leaf proteins putatively involved in regulating tuber generation and/or development in cassava, comparative proteomic approaches have been applied to monitor differentially expressed leaf proteins during root transition from fibrous to tuberous. Stringent cross comparison and statistical analysis between two groups with different plant ages using Student's t test with 95% significance level revealed a number of protein spots whose abundance were significantly altered (P cassava leaves may be involved in storage root development.

  13. [Hair roots induction and culture of Withania somnifera and its withanolide A synthesis].

    Science.gov (United States)

    Wang, Feng-Ying; Sun, Yi-Ming; Lv, Cui-Ping; Cheng, Meng-Qi; Zhang, Lai; Sun, Min

    2014-03-01

    Withanolide A is a biologically active secondary metabolite occuring in roots and leaves of Withania somnifera. In the present study, adventitious roots from leaf explants of W. somnifera were induced for the production of withanolide-A by Agrobacterium tumefaciens strain C58C1 to obtain hair roots. Hair roots induction rate reached 30%. The withanolide A was determined by HPLC in different hair roots lines and different parts of W. somnifera. The average content of withanolide A in all hair roots lines were 1.96 times as high as that in wild-plant, the concentration of withanolide A in hair roots (1.783 mg x g(-1) dry weight) were 1.51 times as high as the roots of wild W. somnifera (1.180 mg x g(-1) dry weight), respectively. It is possible to obtain withanolide A from hair roots culture of W. somnifera.

  14. The role of the transcription factor Rbpj in the development of dorsal root ganglia

    Directory of Open Access Journals (Sweden)

    Chen Jia-Yin

    2011-04-01

    Full Text Available Abstract Background The dorsal root ganglion (DRG is composed of well-characterized populations of sensory neurons and glia derived from a common pool of neural crest stem cells (NCCs, and is a good system to study the mechanisms of neurogenesis and gliogenesis. Notch signaling is known to play important roles in DRG development, but the full scope of Notch functions in mammalian DRG development remains poorly understood. Results In the present study, we used Wnt1-Cre to conditionally inactivate the transcription factor Rbpj, a critical integrator of activation signals from all Notch receptors, in NCCs and their derived cells. Deletion of Rbpj caused the up-regulation of NeuroD1 and precocious neurogenesis in DRG early development but led to an eventual deficit of sensory neurons at later stages, due to reduced cell proliferation and abnormal cell death. In addition, gliogenesis was delayed initially, but a near-complete loss of glia was observed finally in Rbpj-deficient DRG. Furthermore, we found P75 and Sox10, which are normally expressed exclusively in neuronal and glial progenitors of the DRG after the NCCs have completed their migration, were co-expressed in many cells of the DRG of Rbpj conditional knock-out mice. Conclusions Our data indicate that Rbpj-mediated canonical Notch signaling inhibits DRG neuronal differentiation, possibly by regulating NeuroD1 expression, and is required for DRG gliogenesis in vivo.

  15. Development of a space radiation Monte Carlo computer simulation based on the FLUKA and ROOT codes

    CERN Document Server

    Pinsky, L; Ferrari, A; Sala, P; Carminati, F; Brun, R

    2001-01-01

    This NASA funded project is proceeding to develop a Monte Carlo-based computer simulation of the radiation environment in space. With actual funding only initially in place at the end of May 2000, the study is still in the early stage of development. The general tasks have been identified and personnel have been selected. The code to be assembled will be based upon two major existing software packages. The radiation transport simulation will be accomplished by updating the FLUKA Monte Carlo program, and the user interface will employ the ROOT software being developed at CERN. The end-product will be a Monte Carlo-based code which will complement the existing analytic codes such as BRYNTRN/HZETRN presently used by NASA to evaluate the effects of radiation shielding in space. The planned code will possess the ability to evaluate the radiation environment for spacecraft and habitats in Earth orbit, in interplanetary space, on the lunar surface, or on a planetary surface such as Mars. Furthermore, it will be usef...

  16. Advanced nutrient root feeding system for conveyer-type cylindrical plant growth facilities developed for microgravity

    Science.gov (United States)

    Berkovich, Yuliy A.; Smolyanina, Svetlana O.; Krivobok, Anna; Krivobok, Nikolay

    A new brand of cylindrical conveyer-type space plant growth facilities (PGF) has been created to improve of cosmonauts’ diet in the microgravity conditions. Up to date several ground prototypes of the space PGF have been made and tested: “Phytocycle”, “Vitacycle”, “Phytocycle-LED”, “Phytoconveyer”; now the space PGF “Vitacycle-T” for the Russian segment of the ISS is under developing. In the PGFs the ion-exchange salt-saturated fibrous artificial soil (AS) is used as a root medium. We have proposed the system for enrichment of irrigation water by nutrients to decrease of the AS store required for PGF working during the long space mission. The system includes root modules filled in fibrous ion-exchange AS, the enrichment column with crumble salt-saturation ion-exchange resin and the cassette with slow releasing fertilizer (SRF). Both substrates (ion-exchange resin and SRF) are necessary because of the SRF contains mostly N, P and K but another three essential elements S, Ca, Mg are provided by the ion-exchange resin. In the system water goes throw the enrichment column with ion-exchange resin fertilizing by the nutrients and comes into the mixer cell fertilize equipped with the electrical conductivity sensor. When the signal of the conductivity sensor is coming to the controller it turns on the pump directed the water flow throw the cassette with SRF until the electric conductivity of the solution in the mixer cell will reach the setpoint. The nutrient root feeding system was tested during 88 days when Chinese cabbage grew in PGF “Phytocycle-LED”. The crop has been continuously illuminated by red and blue LEDs in the PPF ratio 7 to 1; an integral PPF level has been (240 ± 10) µmol/(m2×s). There was no renewal of the used fibrous AS during the experiment. The PGF total electric power consumption was of 0,45 kW. The average fresh biomass productivity of the PGF during steady state working mode was equal 135×g/day per m2 of the illuminated

  17. A comparative study of monocot and dicot root development in normal /earth/ and hypogravity /space/ environments

    Science.gov (United States)

    Slocum, R. D.; Galston, A. W.

    1982-01-01

    The anatomy and fine structure of roots from oat and mung bean seedlings grown under hypogravity conditions aboard NASA's Space Shuttle were examined and compared to those of roots from ground control plants grown under similar conditions. Oat roots from both sets of plants exhibited normal tissue organization and ultrastructural features, with the exception of cortex cell mitochondria, which characteristically showed a 'swollen' morphology. Flight-grown mung bean roots differed significantly from the controls in that root cap cells were somewhat disorganized and degraded in appearance, especially at the cap periphery. At the EM level, these cells exhibited a loss organelle integrity and a condensed cytoplasm. The potential significance of this finding for the putative gravity-sensing cap cells were noted.

  18. Enzymatic Activity of the Mycelium Compared with Oospore Development During Infection of Pea Roots by Aphanomyces euteiches.

    Science.gov (United States)

    Kjøller, R; Rosendahl, S

    1998-09-01

    ABSTRACT To describe the disease cycle of the root pathogen Aphanomyces euteiches, enzymatic activity in the mycelium was compared with the development of oospores in pea roots. Plants were inoculated with two zoospore concentrations to achieve different disease levels. Hyphae were stained for fungal alkaline phosphatase activity in the roots. Additionally, enzyme activity was measured after electrophoresis of an A. euteiches-specific glucose-6-phosphate isozyme. Development of oospores in the roots was measured after staining the oospores with trypan blue. In plants inoculated with the higher zoospore concentration, the enzymatic activity of the pathogen mycelium peaked 10 to 14 days after inoculation, when oospore formation was initiated. Oospore formation was associated with a gradual increase in disease symptoms. At the last harvest, plants inoculated with the higher zoospore concentration had died. In these plants, oospores were found in 90% of the root length, while the enzymatic activity of the mycelium was low. This suggests that the pathogen mycelium is only active on living plants and does not grow saprophytically on dead plant material.

  19. Enzymatic Activity of the Mycelium Compared with Oospore Development During Infection of Pea Roots by Aphanomyces euteiches

    DEFF Research Database (Denmark)

    Kjøller, Rasmus; Rosendahl, Søren

    1998-01-01

    To describe the disease cycle of the root pathogen Aphanomyces euteiches, enzymatic activity in the mycelium was compared with the development of oospores in pea roots. Plants were inoculated with two zoospore concentrations to achieve different disease levels. Hyphae were stained for fungal alka....... In these plants, oospores were found in 90% of the root length, while the enzymatic activity of the mycelium was low. This suggests that the pathogen mycelium is only active on living plants and does not grow saprophytically on dead plant material.......To describe the disease cycle of the root pathogen Aphanomyces euteiches, enzymatic activity in the mycelium was compared with the development of oospores in pea roots. Plants were inoculated with two zoospore concentrations to achieve different disease levels. Hyphae were stained for fungal...... concentration, the enzymatic activity of the pathogen mycelium peaked 10 to 14 days after inoculation, when oospore formation was initiated. Oospore formation was associated with a gradual increase in disease symptoms. At the last harvest, plants inoculated with the higher zoospore concentration had died...

  20. Cassava (Manihot esculenta Krantz) genome harbors KNOX genes differentially expressed during storage root development.

    Science.gov (United States)

    Guo, D; Li, H L; Tang, X; Peng, S Q

    2014-12-18

    In plants, homeodomain proteins play a critical role in regulating various aspects of plant growth and development. KNOX proteins are members of the homeodomain protein family. The KNOX transcription factors have been reported from Arabidopsis, rice, and other higher plants. The recent publication of the draft genome sequence of cassava (Manihot esculenta Krantz) has allowed a genome-wide search for M. esculenta KNOX (MeKNOX) transcription factors and the comparison of these positively identified proteins with their homologs in model plants. In the present study, we identified 12 MeKNOX genes in the cassava genome and grouped them into two distinct subfamilies based on their domain composition and phylogenetic analysis. Furthermore, semi-quantitative reverse transcription polymerase chain reaction analysis was performed to elucidate the expression profiles of these genes in different tissues and during various stages of root development. The analysis of MeKNOX expression profiles of indicated that 12 MeKNOX genes display differential expressions either in their transcript abundance or expression patterns.

  1. AtFH8 Is Involved in Root Development under Effect of Low-Dose Latrunculin B in Dividing Cells

    Institute of Scientific and Technical Information of China (English)

    Xiu-Hua Xue; Chun-Qing Guo; Fei Du; Quan-Long Lu; Chuan-Mao Zhang; Hai-Yun Ren

    2011-01-01

    Formins have been paid much attention for their potent nucleating activity. However,the connection between the in vivo functions of AtFHs (Arabidopsis thaliana formin homologs) and their effects on actin organization is poorly understood. In this study,we characterized the bundling activity of AtFH8 in vitro and in vivo. Biochemical analysis showed that AtFH8(FH1FH2) could form dimers and bundle preformed actin filaments or induce stellar structures during actin polymerization. Expression of truncated forms of AtFH8 and immunolocalization analysis showed that AtFH8 localized primarily to nuclear envelope in interphase and to the new cell wall after cytokinesis,depending primarily on its N-terminal transmembrane domain. GUS histochemical staining showed AtFH8 was predominantly expressed in Arabidopsis root meristem,vasculature,and outgrowth points of lateral roots. The primary root growth and lateral root initiation of atfh8 could be decreased by latrunculin B (LatB). Analysis of the number of dividing cells in Arabidopsis root tips showed that much fewer dividing cells in Lat B-treated atfh8 plants than wild-type plants,which indicates that AtFH8 was involved in cell division. Actin cytoskeleton in root meristem of atfh8-1 was more sensitive to LatB treatment than that of wild-type. Altogether,our results indicate that AtFH8 is an actin filament nucleator and bundler that functions in cell division and root development.

  2. Adventitious shoot regeneration from the leaves of in vitro grown 'Zhongli 1' pear (Pyrus spp.)

    Institute of Scientific and Technical Information of China (English)

    Jie LIU; Xi ZHANG; Bharat Kumar POUDYAL; Yuxing ZHANG; Zhan JIAO; Jing QI

    2009-01-01

    The pear (Pyrus spp.) is one of the most important temperate fruit crops. The technique of adven-titious shoot regeneration from leaves is considered to be one of the shortcuts in the research on pear genetic modification and cellular engineering, which, however, has not been widely used. As the regeneration frequency of pear leaves is usually very low, the research on adventi-tious shoot regeneration from pear leaves is eagerly needed. In this experiment, the factors affecting shoot and bud regeneration from the leaves of 'Zhongli 1' pear were studied, and an efficient protocol for shoot regenera-tion was established. The results showed that different types of basic media, different combinations of plant growth regulators, leaf placement on medium, periods of dark culture and the use of silver nitrate (AgNO3) on culture media all significantly affected the adventitious shoot regeneration frequency of 'Zhongli 1' pear. The details are as follows: (1) Among three kinds of basic media, NN69 was better for 'Zhongli 1' shoot regenera- tion, followed by half(1/2) MS, while full MS had no effect on shoot regeneration; (2) Thidiazuron (TDZ) was better than 6-benzylaminopurine (6-BA) for 'Zhongli 1' regen-eration, with an optimal concentration of 1.5 mg.L-1, and the regeneration rate under this concentration could reach 85%, with 2.72 buds per leaf. 0.5 mg .L-1 indole-3-butyric acid (IBA), which induced a higher regeneration fre-quency, was a better choice for pear regeneration compared with 0.3 mg.L-1 naphthaleneacetic acid (NAA). Among the different combinations of plant growth regulators, TDZ + IBA was better for inducing high regeneration frequency; (3) The abaxial surface of leaves touching the medium was beneficial for leaves to uptake nutrients from the medium, and because of that, the regeneration fre-quency of leaves was significantly higher than that of leaves touching the medium with their adaxial surfaces (obverse side of leaf); (4) Dark culture was necessary

  3. Development and degeneration of dorsal root ganglia in the absence of the HMG-domain transcription factor Sox10

    DEFF Research Database (Denmark)

    Sonnenberg-Riethmacher, Eva; Miehe, Michaela; Stolt, Claus C.

    2001-01-01

    neurogenesis seemed initially normal. A degeneration of motoneurons and sensory neurons occurred later in development. The mechanism that leads to the dramatic effects on the neural crest derived cell lineages in the dorsal root ganglia (DRG), however, has not been examined up to now. Here, we provide...

  4. The Medicago truncatula CRE1 cytokinin receptor regulates lateral root development and early symbiotic interaction with Sinorhizobium meliloti.

    Science.gov (United States)

    Gonzalez-Rizzo, Silvina; Crespi, Martin; Frugier, Florian

    2006-10-01

    Legumes develop different types of lateral organs from their primary root, lateral roots and nodules, the latter depending on a symbiotic interaction with Sinorhizobium meliloti. Phytohormones have been shown to function in the control of these organogeneses. However, related signaling pathways have not been identified in legumes. We cloned and characterized the expression of Medicago truncatula genes encoding members of cytokinin signaling pathways. RNA interference of the cytokinin receptor homolog Cytokinin Response1 (Mt CRE1) led to cytokinin-insensitive roots, which showed an increased number of lateral roots and a strong reduction in nodulation. Both the progression of S. meliloti infection and nodule primordia formation were affected. We also identified two cytokinin signaling response regulator genes, Mt RR1 and Mt RR4, which are induced early during the symbiotic interaction. Induction of these genes by S. meliloti infection is altered in mutants affected in the Nod factor signaling pathway; conversely, cytokinin regulation of the early nodulin Nodule Inception1 (Mt NIN) depends on Mt CRE1. Hence, cytokinin signaling mediated by a single receptor, Mt CRE1, leads to an opposite control of symbiotic nodule and lateral root organogenesis. Mt NIN, Mt RR1, and Mt RR4 define a common pathway activated during early S. meliloti interaction, allowing crosstalk between plant cytokinins and bacterial Nod factors signals.

  5. A transcription factor with a bHLH domain regulates root hair development in rice

    Institute of Scientific and Technical Information of China (English)

    Wona Ding; Zhiming Yu; Yanli Tong; Wei Huang; Hanmin Chen; Ping Wu

    2009-01-01

    @@ Dear Editor, In plants,root hairs are important organs for the uptake of nutrients and water from the rhizosphere and serve as sites of interaction with soil microorganisms [1].A root hair grows as an extension of a single epidermal cell and is a simple system,making it an elegant model for studying higher plant cell differentiation and cell fate determination.Three types of root hair pattern have been suggested [2,3].Arabidopsis has the striped pattern(Type 3)of root hairs,which has been extensively reported [4,5].Type 2 patterns depend on asymmetrical cell division,which is found in rice(Oryza sativa L.),Barley(Hordeum vulgare)and wheat(Triticum aestivum).

  6. Root-Lesion Nematodes Suppress Cabbage Aphid Population Development by Reducing Aphid Daily Reproduction.

    Science.gov (United States)

    Hol, W H G; Raaijmakers, Ciska E; Mons, Ilse; Meyer, Katrin M; van Dam, Nicole M

    2016-01-01

    Empirical studies have shown that belowground feeding herbivores can affect the performance of aboveground herbivores in different ways. Often the critical life-history parameters underlying the observed performance effects remain unexplored. In order to better understand the cause for the observed effects on aboveground herbivores, these ecological mechanisms must be better understood. In this study we combined empirical experiments with a modeling approach to analyze the effect of two root feeding endoparasitic nematodes with different feeding strategies on the population growth of the aboveground feeding specialist aphid Brevicoryne brassicae on Brassica nigra. The aim was to test whether emerging differences in life history characteristics (days until reproduction, daily reproduction) would be sufficient to explain observed differences in aphid population development on plants with and without two species of nematodes. Aphid numbers were lower on plants with Pratylenchus penetrans in comparison to aphid numbers on plants with Meloidogyne spp. A dedicated experiment showed that aphid daily reproduction was lower on plants with P. penetrans (3.08 offspring female(-1) day(-1)) in comparison to both uninfested plants and plants with Meloidogyne spp. (3.50 offspring female(-1) day(-1)). The species-specific reduction of aphid reproduction appeared independent of changes in amino acids, soluble sugars or the glucosinolate sinigrin in the phloem. An individual-based model revealed that relatively small differences in reproduction rate per female were sufficient to yield a similar difference in aphid populations as was found in the empirical experiments.

  7. Effect of Indoleacetic acid (IAA) on the Negative Phototropism of Rice Root

    Institute of Scientific and Technical Information of China (English)

    MoYi-wei; WANGZhong; QIANShan-qin; GuYun-jie

    2004-01-01

    To explore the effects of IAA on negative phototropism of rice (Oryza sativa L) root, agar block containing IAA was unilaterally applied on root tip to examine the phototropic response of root to exogenous IAA, and microstructure of the bending part was observed with an optical microscope. The growth of seminal roots could be regulated by exogenous IAA as well as light,as a result the root bent towards the site treated, causing asymmetric growth of the root cells at the elongation zone and consequently bending growth. IAA concentration in the shaded side of adventitious root increased much greater at 1.5 h after the start of irradiation. The unequal lateral IAA distribution can be concluded to be the main cause for negative phototropism of rice root.

  8. Root cap specific expression of an endo-beta-1,4-D-glucanase (cellulase): a new marker to study root development in Arabidopsis.

    Science.gov (United States)

    del Campillo, Elena; Abdel-Aziz, Amal; Crawford, Damian; Patterson, Sara E

    2004-09-01

    The sloughing of root cap cells from the root tip is important because it assists the growing root in penetrating the soil. Using a promoter-reporter (GUS) and RT-PCR analysis, we identified an endo-beta-1,4-glucanase (AtCel5) of Arabidopsis thaliana that is expressed exclusively in root cap cells of both primary and secondary roots. Expression is inhibited by high concentrations of IAA, both exogenous and internal, as well as by ABA. AtCel5 expression begins once the mature tissue pattern is established and continues for 3 weeks. GUS staining is observed in both root cap cells that are still attached and cells that have already been shed. Using AtCel5-GUS as a marker, we observed that the root cap cells begin to separate at the sides of the tip while the cells of the central region of the tip separate last. Separation involves sequential tiers of intact cells that separate from the periphery of the root tip. A homozygous T-DNA insertion mutant that does not express AtCel5 forms the root cap and sheds root cap cells but sloughing is less efficient compared to wild type. The reduction in sloughing in the mutant does not affect the overall growth performance of the plant in loose media. The modest effect of abolishing AtCel5 expression suggests that there are multiple redundant genes regulating the process of sloughing of the root cap, including AtCel3/At1g71380, the paralog of the AtCel5 gene that is also expressed in the root cap cells. Thus, these two endo-1,4-beta-D-glucanases may have a role in the sloughing of border cells from the root tip. We propose that AtCel5, provides a new molecular marker to further analyze the process of root cap cell separation and a root cap specific promoter for targeting to the environment genes with beneficial properties for plant growth.

  9. 东北百里香组培再生体系的建立%The Establishment of the Adventitious Bud Regeneration System of Thymus mandschuricus

    Institute of Scientific and Technical Information of China (English)

    王玲; 杨丽鹏; 张秀珍; 马喜娟

    2011-01-01

    以中国特有地被植物东北百里香为试材,研究了植物生长调节剂组合对腋芽萌发和茎段、叶片外植体愈伤诱导和不定芽分化的影响.结果表明:百里香茎段腋芽可直接诱导萌发,在MS+6-BA 0.5mg·L-1+NAA0.1 mg·L-1培养基上萌发率最高,达74%,在MS+6-BA0.5 mg·L-1+NAA0.1 mg·L-1的培养基上增殖倍数为36.43.由茎段萌发的组培苗在1/2MS+IBA 0.5 mg·L-1的培养基中20 d后生根率100%,移栽成活率76.7%.继代培养中叶片外植体可以诱导出愈伤组织,但是不能进一步分化成苗.茎段愈伤诱导的最适培养基为MS+6-BA0.5mg·L-1+2,4-D 1.0mg·L-1,再分化培养基为MS+6-BA(0.1~1.0)mg·L-1+GA3(0.1~0.5)mg·L-1,分化率为33.3%.%Understand the effect of different combinations of plant growth regulators on bud germination, callus growth induction of stem and leaves, and the regeneration of adventitious buds, by using different tissues of Thytnus mandschuricus Ronn., an endemic ground-cover species of China, as explants. The research results indicated that the axillary buds of Th. Mandschuricus can directly germinate in MS + 6-BA 0.5 mg · L-1 + NAA 0.1 mg · L-1 and the germination rate was 74%. The proliferation of axillary buds on MS medium containing 0.5 mg · L-1 6-BA and 0.01 mg · L-1 NAA was achieved to 36.43. The best medium for rooting was 1/2MS + IBA 0.5 mg · L-1. The rooting ratio was 100%. The survival rate reaches 76.7%. Callus can be inducted through the leaf in subculture but can not develop further. The optimizing medium for pedicels explants inducing callus is MS + 6-BA 0.5 mg · L-1 + 2,4-D 1.0 mg · L-1 and inducing multiple buds is MS + 6-BA (0.1-1.0) mg · L-1 + GA3 (0.1-0.5) mg · L-1 with the buds induction frequency of 33.3%.

  10. Gene Networks Involved in Hormonal Control of Root Development in Arabidopsis thaliana: A Framework for Studying Its Disturbance by Metal Stress

    Directory of Open Access Journals (Sweden)

    Stefanie De Smet

    2015-08-01

    Full Text Available Plant survival under abiotic stress conditions requires morphological and physiological adaptations. Adverse soil conditions directly affect root development, although the underlying mechanisms remain largely to be discovered. Plant hormones regulate normal root growth and mediate root morphological responses to abiotic stress. Hormone synthesis, signal transduction, perception and cross-talk create a complex network in which metal stress can interfere, resulting in root growth alterations. We focus on Arabidopsis thaliana, for which gene networks in root development have been intensively studied, and supply essential terminology of anatomy and growth of roots. Knowledge of gene networks, mechanisms and interactions related to the role of plant hormones is reviewed. Most knowledge has been generated for auxin, the best-studied hormone with a pronounced primary role in root development. Furthermore, cytokinins, gibberellins, abscisic acid, ethylene, jasmonic acid, strigolactones, brassinosteroids and salicylic acid are discussed. Interactions between hormones that are of potential importance for root growth are described. This creates a framework that can be used for investigating the impact of abiotic stress factors on molecular mechanisms related to plant hormones, with the limited knowledge of the effects of the metals cadmium, copper and zinc on plant hormones and root development included as case example.

  11. Gene Networks Involved in Hormonal Control of Root Development in Arabidopsis thaliana: A Framework for Studying Its Disturbance by Metal Stress.

    Science.gov (United States)

    De Smet, Stefanie; Cuypers, Ann; Vangronsveld, Jaco; Remans, Tony

    2015-01-01

    Plant survival under abiotic stress conditions requires morphological and physiological adaptations. Adverse soil conditions directly affect root development, although the underlying mechanisms remain largely to be discovered. Plant hormones regulate normal root growth and mediate root morphological responses to abiotic stress. Hormone synthesis, signal transduction, perception and cross-talk create a complex network in which metal stress can interfere, resulting in root growth alterations. We focus on Arabidopsis thaliana, for which gene networks in root development have been intensively studied, and supply essential terminology of anatomy and growth of roots. Knowledge of gene networks, mechanisms and interactions related to the role of plant hormones is reviewed. Most knowledge has been generated for auxin, the best-studied hormone with a pronounced primary role in root development. Furthermore, cytokinins, gibberellins, abscisic acid, ethylene, jasmonic acid, strigolactones, brassinosteroids and salicylic acid are discussed. Interactions between hormones that are of potential importance for root growth are described. This creates a framework that can be used for investigating the impact of abiotic stress factors on molecular mechanisms related to plant hormones, with the limited knowledge of the effects of the metals cadmium, copper and zinc on plant hormones and root development included as case example.

  12. PATTERN OF ROOTING AND GROWTH OF CUTTINGS OF SOME SPECIES OF INSECTICIDAL AND MEDICINAL IMPORTANCE AS AFFECTED BY GROWTH PROMOTING SUBSTANCES

    Directory of Open Access Journals (Sweden)

    Obi, E.A

    2013-06-01

    Full Text Available This study was designed to examine the effects of promoting substances on bud retention, rooting and plantlets survival of rooted cuttings on selected tree species using growth promoting substances. Stem cuttings were treated with rooting-promoting substances, planted in plastic pots filled with top soil and arranged using a completely randomized design (CRD in a screen house. Stem cuttings of pepper fruit, guava, bush mango and cashew were obtained from the Teaching and Research Farm, Federal University of Technology, Akure, Nigeria. The experiments were conducted in 2010. The effects of growth promoting substances namely indole-3-butyric acid (IBA, indole-3-acetic acid (IAA and 1-naphthalene acetic acid (NAA applied 50 µM concentration and coconut water (50% dilution were evaluated on adventitious root formation, shoot growth (bud retention and survival of plantlets of hard- to semi-hardwood cuttings of tested tree species. The effects of growth promoting substances were significant on emergence of plantlets (rooting, growth and survival of plantlets. Number of sprouts (plantlets produced were highest in guava and pepper fruit followed by bush mango and cashew. The cuttings from guava and pepper fruit treated with coconut water and NAA promoted the survival of plantlets. Coconut water and NAA were found better than IBA and IAA in terms of bud retention and rooting, leaf development and survival of plantlets. In most of the tested species, wilting of leaves commenced 6 weeks after planting (WAP and attained 100% mortality thereafter except for pepper fruit cuttings dipped in coconut water. The treatments modified the rooting response among species by promoting percentages of rooting, reduction in bud abscission and plantlet survival. The results affirmed the possibility of propagating plantlets from stem cuttings of the tested species using growth promoting substances.

  13. Effect of Piriformospora indica inoculation on root development and distribution of maize (Zea mays L.) in the presence of petroleum contaminated soil

    Science.gov (United States)

    Zamani, Javad; Hajabbasi, Mohammad Ali; Alaie, Ebrahim

    2014-05-01

    The root systems of most terrestrial plants are confronted to various abiotic and biotic stresses. One of these abiotic stresses is contamination of soil with petroleum hydrocarbon, which the efficiency of phytoremediation of petroleum hydrocarbons in soils is dependent on the ability of plant roots to development into the contaminated soils. Piriformospora indica represents a recently discovered fungus that transfers considerable beneficial impact to its host plants. A rhizotron experiment was conducted to study the effects of P. Indica inoculation on root distribution and root and shoot development of maize (Zea mays L.) in the presence of three patterns of petroleum contamination in the soil (subsurface contamination, continuous contamination and without contamination (control)). Root distribution and root and shoot development were monitored over time. The final root and shoot biomass and the final TPH concentration in the rhizosphere were determined. Analysis of digitized images which were prepared of the tracing of the appeared roots along the front rhizotrons showed the depth and total length of root network in the contamination treatments were significantly decreased. Although the degradation of TPH in the rhizosphere of maize was significant, but there were no significant differences between degradation of TPH in the rhizosphere of +P. indica plants in comparison to -P. indica plants.

  14. NaCl salinity affects lateral root development in Plantago maritima

    NARCIS (Netherlands)

    Rubinigg, M; Wenisch, J; Elzenga, JTM; Stulen, [No Value

    2004-01-01

    Root growth and morphology were assessed weekly in hydroponically-grown seedlings of the halophyte Plantago maritima L. during exposure to 0, 50, 100 and 200 mM NaCl for 21 d. Relative growth rate was reduced by 25% at 200 mM NaCl. The lower NaCl treatments did not affect relative growth rates. Prim

  15. Transcriptome Profiling of Lotus japonicus Roots During Arbuscular Mycorrhiza Development and Comparison with that of Nodulation

    Science.gov (United States)

    Deguchi, Yuichi; Banba, Mari; Shimoda, Yoshikazu; Chechetka, Svetlana A.; Suzuri, Ryota; Okusako, Yasuhiro; Ooki, Yasuhiro; Toyokura, Koichi; Suzuki, Akihiro; Uchiumi, Toshiki; Higashi, Shiro; Abe, Mikiko; Kouchi, Hiroshi; Izui, Katsura; Hata, Shingo

    2007-01-01

    Abstract To better understand the molecular responses of plants to arbuscular mycorrhizal (AM) fungi, we analyzed the differential gene expression patterns of Lotus japonicus, a model legume, with the aid of a large-scale cDNA macroarray. Experiments were carried out considering the effects of contaminating microorganisms in the soil inoculants. When the colonization by AM fungi, i.e. Glomus mosseae and Gigaspora margarita, was well established, four cysteine protease genes were induced. In situ hybridization revealed that these cysteine protease genes were specifically expressed in arbuscule-containing inner cortical cells of AM roots. On the other hand, phenylpropanoid biosynthesis-related genes for phenylalanine ammonia-lyase (PAL), chalcone synthase, etc. were repressed in the later stage, although they were moderately up-regulated on the initial association with the AM fungus. Real-time RT–PCR experiments supported the array experiments. To further confirm the characteristic expression, a PAL promoter was fused with a reporter gene and introduced into L. japonicus, and then the transformants were grown with a commercial inoculum of G. mosseae. The reporter activity was augmented throughout the roots due to the presence of contaminating microorganisms in the inoculum. Interestingly, G. mosseae only colonized where the reporter activity was low. Comparison of the transcriptome profiles of AM roots and nitrogen-fixing root nodules formed with Mesorhizobium loti indicated that the PAL genes and other phenylpropanoid biosynthesis-related genes were similarly repressed in the two organs. PMID:17634281

  16. Does infection by southern root-knot nematode influence development of Phytophthora blight in pepper?

    Science.gov (United States)

    The southern root-knot nematode, Meloidogyne incognita, and Phytophthora capsici, the causal agent of Phytophthora blight, are both important pathogens of pepper (Capsicum annuum L.) in the U.S. and worldwide. Although there is significant information in the literature about the responses of pepper...

  17. Development of root-carving industry leads to ecological and environmental degradation in China

    NARCIS (Netherlands)

    Wang, X.; Xi, W.; Anten, N.P.R.; Bi, H.

    2013-01-01

    Root-carving artwork is among the most highly appreciated traditional forms of art in China because of its ornamental and collection value. However, this ancient and highly appreciated art form is in fact currently a major cause of environmental damage. We argue that the state and local forestry adm

  18. The Deep Roots of the Fairness Committee in Kohlberg's Moral Development Theory

    Science.gov (United States)

    Olson, Christine

    2011-01-01

    Earlier essays in this symposium describe Restorative Justice processes in schools, referred to in our school as a Fairness Committee. Implementing these collaborative, restorative processes does not come without challenges. This essay will explore some of the historical and theoretical roots of the Fairness Committee in Lawrence Kohlberg's work…

  19. Transcript profiling of crown rootless1 mutant stem base reveals new elements associated with crown root development in rice

    Directory of Open Access Journals (Sweden)

    Van Anh Le Thi

    2011-08-01

    Full Text Available Abstract Background In rice, the major part of the post-embryonic root system is made of stem-derived roots named crown roots (CR. Among the few characterized rice mutants affected in root development, crown rootless1 mutant is unable to initiate crown root primordia. CROWN ROOTLESS1 (CRL1 is induced by auxin and encodes an AS2/LOB-domain transcription factor that acts upstream of the gene regulatory network controlling CR development. Results To identify genes involved in CR development, we compared global gene expression profile in stem bases of crl1 mutant and wild-type (WT plants. Our analysis revealed that 250 and 236 genes are down- and up-regulated respectively in the crl1 mutant. Auxin induces CRL1 expression and consequently it is expected that auxin also alters the expression of genes that are early regulated by CRL1. To identify genes under the early control of CRL1, we monitored the expression kinetics of a selected subset of genes, mainly chosen among those exhibiting differential expression, in crl1 and WT following exogenous auxin treatment. This analysis revealed that most of these genes, mainly related to hormone, water and nutrient, development and homeostasis, were likely not regulated directly by CRL1. We hypothesized that the differential expression for these genes observed in the crl1 mutant is likely a consequence of the absence of CR formation. Otherwise, three CRL1-dependent auxin-responsive genes: FSM (FLATENNED SHOOT MERISTEM/FAS1 (FASCIATA1, GTE4 (GENERAL TRANSCRIPTION FACTOR GROUP E4 and MAP (MICROTUBULE-ASSOCIATED PROTEIN were identified. FSM/FAS1 and GTE4 are known in rice and Arabidopsis to be involved in the maintenance of root meristem through chromatin remodelling and cell cycle regulation respectively. Conclusion Our data showed that the differential regulation of most genes in crl1 versus WT may be an indirect consequence of CRL1 inactivation resulting from the absence of CR in the crl1 mutant. Nevertheless

  20. Metabolic profile and root development of Hypericum perforatum L. in vitro roots under stress conditions due to chitosan treatment and culture time

    Directory of Open Access Journals (Sweden)

    Elisa eBrasili

    2016-04-01

    Full Text Available The responses of Hypericum perforatum root cultures to chitosan elicitation had been investigated through 1H-NMR-based metabolomics associated with morpho-anatomical analyses. The root metabolome was influenced by two factors, i.e., time of culture (associated with biomass growth and related overcrowding stress and chitosan elicitation. ANOVA simultaneous component analysis (ASCA modelling showed that these factors act independently. In response to the increase of biomass density over time, a decrease in the synthesis of isoleucine, valine, pyruvate, methylamine, etanolamine, trigonelline, glutamine and fatty acids, and an increase in the synthesis of phenolic compounds, such as xanthones, epicatechin, gallic and shikimic acid were observed. Among the xanthones, brasilixanthone B has been identified for the first time in chitosan-elicited root cultures of H. perforatum. Chitosan treatment associated to a slowdown of root biomass growth caused an increase in DMAPP and a decrease in stigmasterol, shikimic acid and tryptophan levels. The histological analysis of chitosan-treated roots revealed a marked swelling of the root apex, mainly due to the hypertrophy of the first two sub-epidermal cell layers. In addition, periclinal divisions in hypertrophic cortical cells, resulting in an increase of cortical layers, were frequently observed. Most of the metabolic variations as well as the morpho-anatomical alterations occurred within 72 h from the elicitation, suggesting an early response of H. perforatum roots to chitosan elicitation. The obtained results improve the knowledge of the root responses to biotic stress and provide useful information to optimize the biotechnological production of plant compounds of industrial interest.

  1. Metabolic Profile and Root Development of Hypericum perforatum L. In vitro Roots under Stress Conditions Due to Chitosan Treatment and Culture Time.

    Science.gov (United States)

    Brasili, Elisa; Miccheli, Alfredo; Marini, Federico; Praticò, Giulia; Sciubba, Fabio; Di Cocco, Maria E; Cechinel, Valdir Filho; Tocci, Noemi; Valletta, Alessio; Pasqua, Gabriella

    2016-01-01

    The responses of Hypericum perforatum root cultures to chitosan elicitation had been investigated through (1)H-NMR-based metabolomics associated with morpho-anatomical analyses. The root metabolome was influenced by two factors, i.e., time of culture (associated with biomass growth and related "overcrowding stress") and chitosan elicitation. ANOVA simultaneous component analysis (ASCA) modeling showed that these factors act independently. In response to the increase of biomass density over time, a decrease in the synthesis of isoleucine, valine, pyruvate, methylamine, etanolamine, trigonelline, glutamine and fatty acids, and an increase in the synthesis of phenolic compounds, such as xanthones, epicatechin, gallic, and shikimic acid were observed. Among the xanthones, brasilixanthone B has been identified for the first time in chitosan-elicited root cultures of H. perforatum. Chitosan treatment associated to a slowdown of root biomass growth caused an increase in DMAPP and a decrease in stigmasterol, shikimic acid, and tryptophan levels. The histological analysis of chitosan-treated roots revealed a marked swelling of the root apex, mainly due to the hypertrophy of the first two sub-epidermal cell layers. In addition, periclinal divisions in hypertrophic cortical cells, resulting in an increase of cortical layers, were frequently observed. Most of the metabolic variations as well as the morpho-anatomical alterations occurred within 72 h from the elicitation, suggesting an early response of H. perforatum roots to chitosan elicitation. The obtained results improve the knowledge of the root responses to biotic stress and provide useful information to optimize the biotechnological production of plant compounds of industrial interest.

  2. Inhibition of fucosylation of cell wall components by 2-fluoro 2-deoxy-L-fucose induces defects in root cell elongation.

    Science.gov (United States)

    Dumont, Marie; Lehner, Arnaud; Bardor, Muriel; Burel, Carole; Vauzeilles, Boris; Lerouxel, Olivier; Anderson, Charles T; Mollet, Jean-Claude; Lerouge, Patrice

    2015-12-01

    Screening of commercially available fluoro monosaccharides as putative growth inhibitors in Arabidopsis thaliana revealed that 2-fluoro 2-l-fucose (2F-Fuc) reduces root growth at micromolar concentrations. The inability of 2F-Fuc to affect an Atfkgp mutant that is defective in the fucose salvage pathway indicates that 2F-Fuc must be converted to its cognate GDP nucleotide sugar in order to inhibit root growth. Chemical analysis of cell wall polysaccharides and glycoproteins demonstrated that fucosylation of xyloglucans and of N-linked glycans is fully inhibited by 10 μm 2F-Fuc in Arabidopsis seedling roots, but genetic evidence indicates that these alterations are not responsible for the inhibition of root development by 2F-Fuc. Inhibition of fucosylation of cell wall polysaccharides also affected pectic rhamnogalacturonan-II (RG-II). At low concentrations, 2F-Fuc induced a decrease in RG-II dimerization. Both RG-II dimerization and root growth were partially restored in 2F-Fuc-treated seedlings by addition of boric acid, suggesting that the growth phenotype caused by 2F-Fuc was due to a deficiency of RG-II dimerization. Closer investigation of the 2F-Fuc-induced growth phenotype demonstrated that cell division is not affected by 2F-Fuc treatments. In contrast, the inhibitor suppressed elongation of root cells and promoted the emergence of adventitious roots. This study further emphasizes the importance of RG-II in cell elongation and the utility of glycosyltransferase inhibitors as new tools for studying the functions of cell wall polysaccharides in plant development. Moreover, supplementation experiments with borate suggest that the function of boron in plants might not be restricted to RG-II cross-linking, but that it might also be a signal molecule in the cell wall integrity-sensing mechanism.

  3. Development of ESTs from chickpea roots and their use in diversity analysis of the Cicer genus

    Directory of Open Access Journals (Sweden)

    Eshwar K

    2005-08-01

    Full Text Available Abstract Background Chickpea is a major crop in many drier regions of the world where it is an important protein-rich food and an increasingly valuable traded commodity. The wild annual Cicer species are known to possess unique sources of resistance to pests and diseases, and tolerance to environmental stresses. However, there has been limited utilization of these wild species by chickpea breeding programs due to interspecific crossing barriers and deleterious linkage drag. Molecular genetic diversity analysis may help predict which accessions are most likely to produce fertile progeny when crossed with chickpea cultivars. While, trait-markers may provide an effective tool for breaking linkage drag. Although SSR markers are the assay of choice for marker-assisted selection of specific traits in conventional breeding populations, they may not provide reliable estimates of interspecific diversity, and may lose selective power in backcross programs based on interspecific introgressions. Thus, we have pursued the development of gene-based markers to resolve these problems and to provide candidate gene markers for QTL mapping of important agronomic traits. Results An EST library was constructed after subtractive suppressive hybridization (SSH of root tissue from two very closely related chickpea genotypes (Cicer arietinum. A total of 106 EST-based markers were designed from 477 sequences with functional annotations and these were tested on C. arietinum. Forty-four EST markers were polymorphic when screened across nine Cicer species (including the cultigen. Parsimony and PCoA analysis of the resultant EST-marker dataset indicated that most accessions cluster in accordance with the previously defined classification of primary (C. arietinum, C. echinospermum and C. reticulatum, secondary (C. pinnatifidum, C. bijugum and C. judaicum, and tertiary (C. yamashitae, C. chrossanicum and C. cuneatum gene-pools. A large proportion of EST alleles (45% were only

  4. Silencing of ABCC13 transporter in wheat reveals its involvement in grain development, phytic acid accumulation and lateral root formation.

    Science.gov (United States)

    Bhati, Kaushal Kumar; Alok, Anshu; Kumar, Anil; Kaur, Jagdeep; Tiwari, Siddharth; Pandey, Ajay Kumar

    2016-07-01

    Low phytic acid is a trait desired in cereal crops and can be achieved by manipulating the genes involved either in its biosynthesis or its transport in the vacuoles. Previously, we have demonstrated that the wheat TaABCC13 protein is a functional transporter, primarily involved in heavy metal tolerance, and a probable candidate gene to achieve low phytate wheat. In the current study, RNA silencing was used to knockdown the expression of TaABCC13 in order to evaluate its functional importance in wheat. Transgenic plants with significantly reduced TaABCC13 transcripts in either seeds or roots were selected for further studies. Homozygous RNAi lines K1B4 and K4G7 exhibited 34-22% reduction of the phytic acid content in the mature grains (T4 seeds). These transgenic lines were defective for spike development, as characterized by reduced grain filling and numbers of spikelets. The seeds of transgenic wheat had delayed germination, but the viability of the seedlings was unaffected. Interestingly, early emergence of lateral roots was observed in TaABCC13-silenced lines as compared to non-transgenic lines. In addition, these lines also had defects in metal uptake and development of lateral roots in the presence of cadmium stress. Our results suggest roles of TaABCC13 in lateral root initiation and enhanced sensitivity towards heavy metals. Taken together, these data demonstrate that wheat ABCC13 is functionally important for grain development and plays an important role during detoxification of heavy metals.

  5. Callus induction and adventitious bud occurrence from Chinese jujube in the field%田间枣树愈伤组织诱导及不定芽的发生

    Institute of Scientific and Technical Information of China (English)

    徐娟; 王玖瑞; 刘孟军; 刘平; 代丽

    2011-01-01

    以‘星光'和‘月光'2个枣树品种为试材,比较了截干高度和截口粗度、覆盖方式、二甲基亚砜(DMSO)、TDZ(N-苯基-N'-1,2,3-噻二唑-5-基脲)、AgNO3和秋水仙素对田间枝干截面愈伤组织诱导和不定芽发生的影响.结果表明:高枝干截面愈伤发生快,愈伤生长旺盛,截口粗度对截面愈伤的发生有影响,差异显著.“塑料袋+泥+塑料袋”是最佳覆盖方式,此方式枝干截面愈伤发生快,第5天即有透明的愈伤出现,愈伤发生率高达100%,出芽率最高达80%.添加2%二甲基亚砜导致出愈延迟.与水比较,4.0 mg/L TDZ+2.0 mg/L AgNO3对提高出愈率和出芽率并没有显著效果.添加秋水仙素后,不定芽的发生受到抑制,‘星光’和‘月光’均在0.025%秋水仙素时出现最小值,分别为45%和5%.与‘月光'比较,‘星光'枝干截面出愈快,出芽率高,可能更容易染色体诱变.%Effect of stumping height and cutting diameter of branches,covering types, dimethyl sulfoxide (DMSO), TDZ (Thidiazuron), AgNO3 and colchicine on callus induction and adventitious occurrence from cross section of Chinese jujube in the field was investigated by using two varieties of Zizyphus jujube Mill. Cv. 'Xingguang'and 'Yueguang'. The results showed callus from cross section of higher branches formed early and developed quickly. Callus formation varied significantly with branch cutting diameter. 'Plastic bag+ mud + plastic bag' was the optimal covering type for callus induction and adventitious bud occurrence on cross section of branches, by which callus occurred so rapidly that transparent callus was visible in 5 days. Finally callus rate was as high as 100% and adventitious bud rate reached 80%. Callus formed lately when 2% DMSO was added. 4. 0 mg/L TDZ+2. 0 mg/L AgNO3 did not obviously accelerate callus induction and adventitious bud formation. However, adventitious bud was hindered by colchicines. 0. 025% colchicines caused the least rate

  6. Root development of fodder radish and winter wheat before winter in relation to uptake of nitrogen

    DEFF Research Database (Denmark)

    Wahlström, Ellen Margrethe; Hansen, Elly Møller; Mandel, A.;

    2015-01-01

    ) at depleting the soil of mineral nitrogen (Nmin) before winter. A secondary aim was to study the agreement between three different root measuring methods: root wash (RW), core break (CB) and minirhizotron (MR). The third aim of the was to correlate the N uptake of FR and WW with RLD. An experiment was made......The nitrate (N) present in soil at the end of autumn is prone to leach during winter and spring in temperate climates if not taken up by plants. In Denmark catch crops are used as a regulatory tool to reduce N leaching and therefore a shift from winter cereals to spring cereals with catch crops has...... to see if and how root growth was affected by the minirhizotron tube. The experiments were conducted on a Danish sandy loam soil. From September to November the amount of soil Nmin decreased from 49kgNha-1 to 14kgNha-1 under FR and increased from 28kgNha-1 to 44kgNha-1 under WW. A test of correlations...

  7. miRNA164-directed cleavage of ZmNAC1 confers lateral root development in maize (Zea mays L.

    Directory of Open Access Journals (Sweden)

    Li Jing

    2012-11-01

    Full Text Available Abstract Background MicroRNAs are a class of small, non-coding RNAs that regulate gene expression by binding target mRNA, which leads to cleavage or translational inhibition. The NAC proteins, which include NAM, ATAF, and CUC, are a plant-specific transcription factor family with diverse roles in development and stress regulation. It has been reported that miR164 negatively regulates NAC1 expression, which in turn affects lateral root development in Arabidopsis; however, little is known about the involvement of the maize NAC family and miR164 in lateral root development. Results We collected 175 maize transcripts with NAC domains. Of these, 7 ZmNACs were putative targets for regulation by miR164. We isolated one gene, called TC258020 (designated ZmNAC1 from 2 maize inbred lines, 87-1 and Zong3. ZmNAC1 had a high expression level in roots and showed higher abundance (1.8 fold in Zong3 relative to 87-1, which had less lateral roots than Zong3. There was a significant correlation between the expression level of ZmNAC1 and the lateral root density in the recombinant inbred line (RIL population. Transgenic Arabidopsis that overexpressed ZmNAC1 had increased lateral roots in comparison to the wild type. These findings suggest that ZmNAC1 played a significant role in lateral root development. An allelic expression assay showed that trans-regulatory elements were the dominant mediators of ZmNAC1 differential expression in 87-1 and Zong3, and further analysis revealed that miR164 was a trans-element that guided the cleavage of endogenous ZmNAC1 mRNA. Both mature miR164 and miR164 precursors had higher expression in 87-1 than Zong3, which was the opposite of the expression pattern of ZmNAC1. Additionally, the allelic assay showed that the cis-regulatory element most likely affected Zm-miR164b's expression pattern. A β-glucuronidase (GUS assay showed that the Zm-miR164b promoter had higher GUS activity in 87-1 than in Zong3. In addition, we detected mi

  8. Genetic association among root morphology, root quality and root yield in ashwagandha (Withania somnifera

    Directory of Open Access Journals (Sweden)

    Kumar Ramesh R.

    2011-01-01

    Full Text Available Ashwagandha (Withania somnifera is a dryland medicinal crop and roots are used as valuable drug in traditional systems of medicine. Morphological variants (morphotypes and the parental populations were evaluated for root - morphometric, quality and yield traits to study genetic association among them. Root morphometric traits (root length, root diameter, number of secondary roots/ plant and crude fiber content exhibited strong association among them and showed significant positive genotypic correlation with yield. Starch-fiber ratio (SFR, determinant of brittle root texture showed strong negative association with root yield. The total alkaloid content had positive genotypic correlation with root yield. So genetic upgradation should aim at optimum balance between two divergent groups of traits i.e. root yield traits (root morphometric traits and crude fiber content and root textural quality traits (starch content and SFR to develop superior genotypes with better yield and quality.

  9. Flood-Ring Formation and Root Development in Response to Experimental Flooding of Young Quercus robur Trees

    Science.gov (United States)

    Copini, Paul; den Ouden, Jan; Robert, Elisabeth M. R.; Tardif, Jacques C.; Loesberg, Walter A.; Goudzwaard, Leo; Sass-Klaassen, Ute

    2016-01-01

    Spring flooding in riparian forests can cause significant reductions in earlywood-vessel size in submerged stem parts of ring-porous tree species, leading to the presence of ‘flood rings’ that can be used as a proxy to reconstruct past flooding events, potentially over millennia. The mechanism of flood-ring formation and the relation with timing and duration of flooding are still to be elucidated. In this study, we experimentally flooded 4-year-old Quercus robur trees at three spring phenophases (late bud dormancy, budswell, and internode expansion) and over different flooding durations (2, 4, and 6 weeks) to a stem height of 50 cm. The effect of flooding on root and vessel development was assessed immediately after the flooding treatment and at the end of the growing season. Ring width and earlywood-vessel size and density were measured at 25- and 75-cm stem height and collapsed vessels were recorded. Stem flooding inhibited earlywood-vessel development in flooded stem parts. In addition, flooding upon budswell and internode expansion led to collapsed earlywood vessels below the water level. At the end of the growing season, mean earlywood-vessel size in the flooded stem parts (upon budswell and internode expansion) was always reduced by approximately 50% compared to non-flooded stem parts and 55% compared to control trees. This reduction was already present 2 weeks after flooding and occurred independent of flooding duration. Stem and root flooding were associated with significant root dieback after 4 and 6 weeks and mean radial growth was always reduced with increasing flooding duration. By comparing stem and root flooding, we conclude that flood rings only occur after stem flooding. As earlywood-vessel development was hampered during flooding, a considerable number of narrow earlywood vessels present later in the season, must have been formed after the actual flooding events. Our study indicates that root dieback, together with strongly reduced hydraulic

  10. Biochemical investigations during in vitro adventitious shoot regeneration in leaflet explants from nodal segments of a mature Albizia procera tree

    Institute of Scientific and Technical Information of China (English)

    Ekta Rai; Sulochna Bouddha; Shamim Akhtar Ansari

    2016-01-01

    The in vitro adventitious shoot differentiation in leaflet explants of an adult tree differed from that of leaflet explants of seedlings of Albizia procera (Roxb.) Benth. reported previously elsewhere. The leaflet explants from an adult tree passed through an initial callus phase for 30 days on MS medium supplemented with 3% sucrose, 2.5 lM 2,4-D followed by a subsequent adventitious shoot differentiation phase for another 30 days on half MS medium supplemented with 0.25 lM each of BA and IBA. The regeneration rate of in vitro adventitious shoots in explants from the adult tree, i.e.1.66 shoots/callus, was lower than that from seedlings, i.e. [10 shoots/callus, which was reported elsewhere. Correspondingly, the activities of nitrate reductase and peroxidase, and endogenous phenol content remained very low during in vitro adventitious shoot differentiation in leaflet explants of an adult tree possibly due to lower availability of competent stem (juvenile) cells for the process.

  11. Consequences of Adventitious Presence of Non-Approved GMOs in Seeds: the Case of Maize Seeds in Germany

    NARCIS (Netherlands)

    Wree, Philipp; Wesseler, Justus

    2016-01-01

    In Germany, seeds have a zero tolerance for traces of GMOs which are not approved for cultivation in the EU (Bundesverwaltungsgericht 2012). However, adventitious presence of unapproved events in seeds may happen. That can be the cause for unintended release of GMOs into the environment. Two of thes

  12. RNA-Seq analysis identifies key genes associated with haustorial development in the root hemiparasite Santalum album

    Directory of Open Access Journals (Sweden)

    Xinhua eZhang

    2015-09-01

    Full Text Available Santalum album (sandalwood is one of the economically important plant species in the Santalaceae for its production of highly valued perfume oils. Sandalwood is also a hemiparasitic tree that obtains some of its water and simple nutrients by tapping into other plants through haustoria which are highly specialized organs in parasitic angiosperms. However, an understanding of the molecular mechanisms involved in haustorium development is limited. In this study, RNA sequencing (RNA-seq analyses were performed to identify changes in gene expression and metabolic pathways associated with the development of the S. album haustorium. A total of 56,011 non-redundant contigs with a mean contig size of 618 bp were obtained by de novo assembly of the transcriptome of haustoria and non-haustorial seedling roots. A substantial number of the identified differentially expressed genes were involved in cell wall metabolism and protein metabolism, as well as mitochondrial electron transport functions. Phytohormone-mediated regulation might play an important role during haustorial development. Especially, auxin signaling is likely to be essential for haustorial initiation, and genes related to cytokinin and gibberellin biosynthesis and metabolism are involved in haustorial development. Our results suggest that genes encoding nodulin-like proteins may be important for haustorial morphogenesis in S. album. The obtained sequence data will become a rich resource for future research in this interesting species. This information improves our understanding of haustorium development in root hemiparasitic species and will allow further exploration of the detailed molecular mechanisms underlying plant parasitism.

  13. Conservation of root regeneration potential of cell aggregates from horseradish hairy roots used as artificial seeds

    Energy Technology Data Exchange (ETDEWEB)

    Repunte, V.; Taya, M.; Tone, S. [Osaka University, Osaka (Japan). Faculty of Engineering Science

    1996-10-20

    The effects of water content in agar gel used as a medium and oxygen level in the gas phase on the adventitious root regeneration of cell aggregates (CA) derived from horseradish hairy roots were investigated in cultures at 25{degree}C. The number of roots emerging from CA was highly dependent on water content of the agar gel and no root regeneration was observed at a gel water content of 66% during culture time of 20 days. CA root regeneration was suppressed when the CA were kept for 20 days in an atmosphere oxygen composition of 10%, but was restored upon transfer of the CA to normal atmosphere of 21% oxygen. On the basis of these findings, an artificial seed was proposed using the CA as a cell inclusion material encapsulated in alginate gels covered with coats. From the perspective of conserving the root regeneration potential of the CA by preventing the drying of alginate gel while keeping oxygen availability to the CA, different coating materials of ethylene vinyl acetate acrylic acid terpolymer, paraffin and polyorganosiloxane were tested. Paraffin was selected as a suitable coating material because of its efficient drying tolerance and adequate permeability to oxygen. A regeneration efficiency of 90% could be obtained from the CA, stored in alginate gel covered with a paraffin coating of 0.40 mm thickness at 25{degree}C for 60 days in air, when sucrose concentration in the gel was over 240 mol m{sup -3}. 25 refs., 8 figs.

  14. Transforming growth factor-β1 involved in urotensin Ⅱ-induced phenotypic differentiation of adventitial fibroblasts from rat aorta

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yong-gang; HU Yan-chao; MAO Yan-yan; WEI Rui-hong; BAO Shi-lin; WU Li-biao; KUANG Ze-jian

    2010-01-01

    Background Urotensin Ⅱ (UⅡ) is a new vasoconstrictive peptide that may activate the adventitial fibroblasts.Transforming growth factor-β1 (TGF-β1) is an important factor that could induce the phenotypical transdifferentiation of adventitial fibroblasts. This study aimed to explore whether TGF-β1 is involved in UⅡ-induced phenotypic differentiation of adventitial fibroblasts from rat aorta.Methods Adventitial fibroblasts were prepared by the explant culture method. TGF-β1 protein secretion from the cells was determined by enzyme-linked immunosorbent assay (ELISA). The mRNA and protein expression of α-smooth nuscle actin (α-SM-actin), the marker of phenotypic differentiation from fibroblasts to myofibroblasts, were determined using real-time quantitative RT-PCR (real-time RT-PCR) and Western blotting, respectively.Results UⅡ stimulated the secretion of TGF-β1 in cultured adventitial fibroblasts in a time-dependent manner. The secretion reached a peak at 24 hours, was higher by 69.8% (P <0.01), than the control group. This effect was also concentration dependent. Maximal stimulation was reached at 10-8 mol/L of UⅡ (P <0.01), which was increased by 59.9%,compared with in the control group (P <0.01). The secretion of TGF-β1 induced by UⅡ was significantly blocked by SB-710411 (10-7 mol/L), a specific antagonist of UⅡ receptor. In addition, both UⅡ (10-8 mol/L) and TGF-β1 significantly stimulated α-SM-actin mRNA and protein expression. Moreover, the α-SM-actin induced by UⅡ was inhibited by the specific neutralizing antibody (20 μg/ml) of TGF-β1, while the α-SM-actin expression stimulated by TGF-β1 (20 ng/ml)was inhibited by SB-710411 (10-7 mol/L), the UⅡ receptor antagonist.Conclusion This study suggests that UⅡ could induce TGF-β1 secretion in adventitial fibroblasts via UT activation, and TGF-β1 might be involved in phenotypic differentiation from adventitial fibroblasts into myofibroblasts induced by UⅡ, and TGF-β1

  15. Adventitious Shoots Regeneration from Leaves of Soft-seeded Pomegranate ( Punica granatum L.cv.Yushizi)%软籽石榴(Punica granatum L.cv.Yushizi)叶片再生体系的研究

    Institute of Scientific and Technical Information of China (English)

    张全军; 秦改花; 黄文江; 许天龙

    2012-01-01

    为建立软籽石榴的离体高效再生体系,试验以新梢为材料建立了软籽石榴的无菌体系,并试验了不同激素组合对软籽石榴增殖效果的影响;以叶片为外植体研究了不同培养基组合对不定芽再生频率和伸长的影响.结果表明,茎段增殖培养的最适培养基为MS +6-BA 0.3 mg/L+ KT0.3 ~0.4 mg/L+ NAA 0.1 mg/L;叶片不定芽诱导的最适培养基为MS +TDZ 0.6mg/L+NAA 0.2 mg/L,在不定芽诱导培养基中添加0.6 mg/L的GA3对不定芽的伸长效果较好.在1/2MS+ NAA 0.2 mg/L+ BA 0.2 mg/L+ AC 0.5g/L培养基增殖培养所得芽苗生根效果最优.%To establish the system of rapid in vitro propagation of pomegranate, stems were used to study the effects of different hormone combination on the multiplication of shoots; the leaves were used to study the effects of different hormone combination on the adventitious shoots inducement, then rooting of shoots were studied. The results showed that the optimum media for multiplication of shoots were MS +6-BA0. 3 mg/L+ KT0.3-0.4 mg/L + NAA 0. 1mg/L, the optimum media for adventitious buds inducement were MS + TDZ 0.6 mg/L + NAA 0. 2 mg/L, the adventitious buds grew well on the inducement medium added GA0.6 mg/L, the optimum media for rooting were 1/2MS + NAA 0.2 mg/L+ IBA 0.2 mg/L + AC 0.5 g/L.

  16. Development of a multiplex Q-PCR to detect Trichoderma harzianum Rifai strain T22 in plant roots.

    Science.gov (United States)

    Horn, Ivo R; van Rijn, Menno; Zwetsloot, Tom J J; Basmagi, Said; Dirks-Mulder, Anita; van Leeuwen, Willem B; Ravensberg, Willem J; Gravendeel, Barbara

    2016-02-01

    The fungal species Trichoderma harzianum is widely used as a biological agent in crop protection. To verify the continued presence of this fungus on plant roots manually inoculated with T. harzianum strain T22, a Q-PCR was designed using specific probes for this particular strain. To develop these molecular diagnostic tools, genome mining was first carried out to retrieve putative new regions by which different strains of T. harzianum could be distinguished. Subsequently, Sanger sequencing of the L-aminoacid oxidase gene (aox1) in T. harzianum was applied to determine the mutations differing between various strains isolated from the Trichoderma collection of Koppert Biological Systems. Based on the sequence information obtained, a set of hydrolysis probes was subsequently developed which discriminated T. harzianum T22 strains varying in only a single nucleotide. Probes designed for two strains uniquely recognized the respective strains in Q-PCR with a detection limit of 12,5ng DNA. Titration assays in which T. harzianum DNA from distinct strains was varied further underscored the specificity of the probes. Lastly, fungal DNA extracted from roots of greenhouse cultured tomato plants was analyzed using the probe-based assay. DNA from T. harzianum strain T22 could readily be identified on roots of greenhouse reared tomato plants inoculated with varying concentrations up to one week after treatment with a detection limit of 3e6 colony forming units of T. harzianum T22. We conclude that the Q-PCR method is a reliable and robust method for assessing the presence and quantity of T. harzianum strain T22 in manually inoculated plant material. Our method provides scope for the development of DNA based strain specific identification of additional strains of Trichoderma and other fungal biological control agents.

  17. A tetratricopeptide repeat domain-containing protein SSR1 located in mitochondria is involved in root development and auxin polar transport in Arabidopsis.

    Science.gov (United States)

    Zhang, Min; Wang, Cuiping; Lin, Qingfang; Liu, Aihua; Wang, Ting; Feng, Xuanjun; Liu, Jie; Han, Huiling; Ma, Yan; Bonea, Diana; Zhao, Rongmin; Hua, Xuejun

    2015-08-01

    Auxin polar transport mediated by a group of Pin-formed (PIN) transporters plays important roles in plant root development. However, the mechanism underlying the PIN expression and targeting in response to different developmental and environmental stimuli is still not fully understood. Here, we report a previously uncharacterized gene SSR1, which encodes a mitochondrial protein with tetratricopeptide repeat (TPR) domains, and show its function in root development in Arabidopsis thaliana. In ssr1-2, a SSR1 knock-out mutant, the primary root growth was dramatically inhibited due to severely impaired cell proliferation and cell elongation. Significantly lowered level of auxin was found in ssr1-2 roots by auxin measurement and was further supported by reduced expression of DR5-driven reporter gene. As a result, the maintenance of the root stem cell niche is compromised in ssr1-2. It is further revealed that the expression level of several PIN proteins, namely, PIN1, PIN2, PIN3, PIN4 and PIN7, were markedly reduced in ssr1-2 roots. In particular, we showed that the reduced protein level of PIN2 on cell membrane in ssr1-2 is due to impaired retrograde trafficking, possibly resulting from a defect in retromer sorting system, which destines PIN2 for degradation in vacuoles. In conclusion, our results indicated that SSR1 is functioning in root development in Arabidopsis, possibly by affecting PIN protein expression and subcellular targeting.

  18. Auxin-Independent NAC Pathway Acts in Response to Explant-Specific Wounding and Promotes Root Tip Emergence during de Novo Root Organogenesis in Arabidopsis.

    Science.gov (United States)

    Chen, Xiaodong; Cheng, Jingfei; Chen, Lyuqin; Zhang, Guifang; Huang, Hai; Zhang, Yijing; Xu, Lin

    2016-04-01

    Plants have powerful regenerative abilities that allow them to recover from damage and survive in nature. De novo organogenesis is one type of plant regeneration in which adventitious roots and shoots are produced from wounded and detached organs. By studying de novo root organogenesis using leaf explants of Arabidopsis (Arabidopsis thaliana), we previously suggested that wounding is the first event that provides signals to trigger the whole regenerative process. However, our knowledge of the role of wounding in regeneration remains limited. In this study, we show that wounding not only triggers the auxin-mediated fate transition of regeneration-competent cells, but also induces the NAC pathway for root tip emergence. The NAC1 transcription factor gene was specifically expressed in response to wounding in the leaf explant, but not in the wounded leaf residue of the source plant. Inhibition of the NAC1 pathway severely affected the emergence of adventitious root tips. However, the NAC1 pathway functioned independently of auxin-mediated cell fate transition and regulates expression of CEP genes, which encode proteins that might have a role in degradation of extensin proteins in the cell wall. Overall, our results suggest that wounding has multiple roles in de novo root organogenesis and that NAC1 acts as one downstream branch in regulating the cellular environment for organ emergence.

  19. In vitro plant development and root colonization of Coleus forskohlii by Piriformospora indica.

    Science.gov (United States)

    Das, Aparajita; Tripathi, Swati; Varma, Ajit

    2014-03-01

    The present study was conducted for optimization of in vitro substrates under aseptic conditions for interaction of Piriformospora indica with the medicinal plant Coleus forskohlii. It aims to test the effects of different substrates on P. indica colonization as well as growth parameters of the in vitro raised C. forskohlii. Interaction of in vitro C. forskohlii with root endophyte P. indica under aseptic condition resulted in increase in growth parameters in fungus colonized plants. It was observed that P. indica promoted the plant's growth in all irrespective of substrates used for co-culture study. The growth was found inferior in liquid compared to semisolid medium as well as there was problem of hyperhydricity in liquid medium. P. indica treated in vitro plantlets were better adapted for establishment under green house compared to the non treated plants due to fungal intervention.

  20. Enhanced Segmentation Procedure for Intima- Adventitial Layers of Common Carotid Artery

    Directory of Open Access Journals (Sweden)

    V.Savithri

    2010-09-01

    Full Text Available Abstract— This paper presents an enhanced Segmentationtechnique for use on noisy B-mode ultrasound images of thecarotid artery. This method is based on ImageEnhancement, Edge detection and Morphological operationsin boundary detection. This procedure may simplify the jobof the practitioner for analyzing accuracy and variability ofsegmentation results. Possible plaque regions are alsohighlighted. A thorough evaluation of the method in the clinicalenvironment shows that inter observer variability is evidentlydecreased and so is the overall analysis time. Theresults demonstrate that it has the potential to performqualitatively better than applying existing methods inintima and adventitial layer detection on B-mode images.Keywords— Artery, boundary detection, imaging, Ultrasonic,parallel programming

  1. Arabidopsis NITRILASE 1 Contributes to the Regulation of Root Growth and Development through Modulation of Auxin Biosynthesis in Seedlings.

    Science.gov (United States)

    Lehmann, Thomas; Janowitz, Tim; Sánchez-Parra, Beatriz; Alonso, Marta-Marina Pérez; Trompetter, Inga; Piotrowski, Markus; Pollmann, Stephan

    2017-01-01

    Nitrilases consist of a group of enzymes that catalyze the hydrolysis of organic cyanides. They are found ubiquitously distributed in the plant kingdom. Plant nitrilases are mainly involved in the detoxification of ß-cyanoalanine, a side-product of ethylene biosynthesis. In the model plant Arabidopsis thaliana a second group of Brassicaceae-specific nitrilases (NIT1-3) has been found. This so-called NIT1-subfamily has been associated with the conversion of indole-3-acetonitrile (IAN) into the major plant growth hormone, indole-3-acetic acid (IAA). However, apart of reported functions in defense responses to pathogens and in responses to sulfur depletion, conclusive insight into the general physiological function of the NIT-subfamily nitrilases remains elusive. In this report, we test both the contribution of the indole-3-acetaldoxime (IAOx) pathway to general auxin biosynthesis and the influence of altered nitrilase expression on plant development. Apart of a comprehensive transcriptomics approach to explore the role of the IAOx route in auxin formation, we took a genetic approach to disclose the function of NITRILASE 1 (NIT1) of A. thaliana. We show that NIT1 over-expression (NIT1ox) results in seedlings with shorter primary roots, and an increased number of lateral roots. In addition, NIT1ox plants exhibit drastic changes of both free IAA and IAN levels, which are suggested to be the reason for the observed phenotype. On the other hand, NIT2RNAi knockdown lines, capable of suppressing the expression of all members of the NIT1-subfamily, were generated and characterized to substantiate the above-mentioned findings. Our results demonstrate for the first time that Arabidopsis NIT1 has profound effects on root morphogenesis in early seedling development.

  2. Differential effects of fenpropimorph and fenhexamid, two sterol biosynthesis inhibitor fungicides, on arbuscular mycorrhizal development and sterol metabolism in carrot roots.

    Science.gov (United States)

    Campagnac, Estelle; Fontaine, Joël; Sahraoui, Anissa Lounès-Hadj; Laruelle, Frédéric; Durand, Roger; Grandmougin-Ferjani, Anne

    2008-12-01

    Sterols composition of transformed carrot roots incubated in presence of increasing concentrations of fenpropimorph (0.02; 0.2; 2mgl(-1)) and fenhexamid (0.02; 0.2; 2; 20mgl(-1)), colonized or not by Glomus intraradices was determined. In mycorrhizal roots treated with fenpropimorph, normal Delta(5)-sterols were replaced by unusual compounds such as 9beta,19-cyclopropylsterols (24-methylpollinastanol), Delta(8,14)-sterols (ergosta-8,14-dienol, stigmasta-8,14-dienol), Delta(8)-sterols (Delta(8) sitosterol) and Delta(7)-sterols (ergosta-7,22-dienol). After application of fenpropimorph, a drastic reduction of the mycorrhizal root growth, root colonization and extraradical fungal development was observed. Application of fenhexamid did not modify sterol profiles and the total colonization of roots. But the arbuscule frequency of the fungal partner was significantly affected. Comparison of the effects caused by the tested fungicides indicates that the usual phytosterols may be involved in symbiosis development. Indeed, observed modifications of root sterols composition could explain the high fenpropimorph toxicity to the AM symbiosis. However, the absence of sterolic modifications in the roots treated with fenhexamid could account for its more limited impact on mycorrhization.

  3. Development and evaluation of two root caries controlling programmes for home-based frail people older than 75 years

    DEFF Research Database (Denmark)

    Ekstrand, Kim; Martignon, Stefania; Holm-Pedersen, Poul

    2008-01-01

    (i) Initially, to devise and examine the validity of a system for determining lesion activity on root surfaces, and (ii) compare the effectiveness of two preventive programmes in controlling root caries in elderly people using the devised system....

  4. [In vitro evaluation of fracture resistance of teeth with incomplete root development and intracanal reinforcement with different materials].

    Science.gov (United States)

    Cabrales Salgado, Ricardo; Carvajal Cabrales, Katherine; Pupo Marrugo, Stella; Hernández González, Daniel Fernando; Gracia Bárcenas, José Luis

    2012-09-01

    The aim of this study was to evaluate the fracture resistance of teeth with incomplete root development and intracanal reinforcement with adhesives materials. 50 human central and lateral incisors were instrumented and prepared to simulate an immature tooth and filled apically with MTA. The samples were divided into four experimental groups and one control group. Group 1: resin composite Filtek P90; Group 2: glass Ionomer Vitremer; Group 3: resin composite Filtek Z350 XT; Group 4: glass Ionomer Ketac N 100; Group 5: negative control (instrumented but not reinforced). After, the fracture test was performed using a fracture universal testing machine (Instron). The maximum values of resistance before catastrophic fracture were collected and analyzed by Anova (p = 0.05). The results show a significant difference between the groups compared (p = 0.02). A significant difference was found between group 1 (847.73 N) and group 5 (474.77 N) (p = 0.02) applying the Bonferroni test. Despite the limitations of the study, the conclusion is that micro-hybrid composite resins are ideal materials to strengthen teeth with incomplete root development endodontically treated.

  5. Analysis of Factors Controlling Cell Cycle that Can Be Synchronized Nondestructively During Root Cap Development

    Energy Technology Data Exchange (ETDEWEB)

    Martha Hawes

    2011-02-04

    Publications and presentations during the final funding period, including progress in defining the substrate specificity, the primary goal of the project, are listed below. Both short-term and long-term responses mediated by PsUGT1 have been characterized in transgenic or mutant pea, alfalfa, and Arabidopsis with altered expression of PsUGT1. Additional progress includes evaluation of the relationship between control of the cell cycle by PsUGT1 and other glycosyltransferase and glycosidase enzymes that are co-regulated in the legume root cap during the onset of mitosis and differentiation. Transcriptional profiling and multidimensional protein identification technology ('MudPIT') have been used to establish the broader molecular context for the mechanism by which PsUGT1 controls cell cycle in response to environmental signals. A collaborative study with the Norwegian Forest Research Institute (who provided $10,000.00 in supplies and travel funds for collaborator Dr. Toril Eldhuset to travel to Arizona and Dr. H. H. Woo to travel to Norway) made it possible to establish that the inducible root cap system for studying carbohydrate synthesis and solubilization is expressed in gymnosperm as well as angiosperm species. This discovery provides an important tool to amplify the potential applications of the research in defining conserved cell cycle machinery across a very broad range of plant species and habitats. The final work, published during 2009, revealed an additional surprising parallel with mammalian immune responses: The cells whose production is controlled by PsUGT1 appear to function in a manner which is analogous to that of white blood cells, by trapping and killing in an extracellular manner. This may explain why mutation within the coding region of PsUGT1 and its homolog in humans (UGT1) is lethal to plants and animals. The work has been the subject of invited reviews. A postdoctoral fellow, eight undergraduate students, four M.S. students and

  6. Effects of Different Kinds of Exogenous Auxin on the Growth of Rice Roots under Cadmium Stress%不同外源生长素对镉胁迫水稻根系生长的影响

    Institute of Scientific and Technical Information of China (English)

    韩明明; 胡凡; 王凯; 赵凤云

    2010-01-01

    以水稻中花11号为材料,测定了不同外源生长素对镉胁迫水稻根系生长发育的影响.结果表明,0.1 mmol/L镉诱导水稻初生根、不定根和侧根的伸长生长且侧根的数目也增加,但抑制地上部分的生长.在镉胁迫下添加不同浓度的生长素如NAA、IAA、IBA和2,4-D都明显改变根系的生长且变化趋势相似.即浓度为10-9~10-7M时,促进镉胁迫水稻初生根和不定根的伸长生长,其中以浓度为10-8M时,促进作用最强;当浓度高于10-7M时,反而抑制了根的生长;添加4种外源生长素均不能解除镉对地上部分的抑制作用,不过镉胁迫下添加10-9~10-8M的NAA能在一定程度上改善镉胁迫水稻的生长.在相同浓度条件下,不同生长素对初生根和不定根上侧根的形成和发育既有相似之处,也存在一定差异.%[Objective]The aim was to study the effect of different kinds of exogenous auxin on the growth of rice roots under cadmium stress.[Method]Oryza sativa L.cv Z.honghua No.11 was used as experimental materials to detect the effect of different kinds of exogenous auxin on the growth of rice roots.[Result]The results showed that 0.1 mmol/L Cd treatment could not only increase primary,adventitious and lateral root length but also lateral root number,whereas the shoot growth was inhibited.When supplemented with different concentrations of NAA,IAA,IBA and 2,4-D,the growth of root system varied and similar change trend had been found.At the auxin concentration of 10-9-10-7 moVL in particular 10-8 mol/L,all four kinds of auxin promoted the elongation growth of primary and adventitious roots,but inhibition was observed when auxin was higher than 10-7 mol/L.The decreased shoot growth caused by Cd could not be counteracted by supplementing with the four kinds of auxin.However,at the auxin concentration of 10-9-10-8 mol/L,NAA could improve rice growth under Cd stress condition.The formation and development of lateral roots on primary and

  7. Chemical composition fluctuations in roots of Plumbago scandens L. in relation to floral development

    Directory of Open Access Journals (Sweden)

    Selma R. Paiva

    2011-12-01

    Full Text Available Plumbago scandens L. is a Brazilian tropical/subtropical species that occurs along the coast. Chemically it is mainly represented by naphthoquinones, flavonoids, terpenoids and steroids. The aim of the present work is to study quantitative changes in the root metabolic production of Plumbago scandens during different physiologic developmental stages relative to floration. The results indicated the presence of four substances in the extracts: plumbagin, epi-isoshinanolone, palmitic acid and sitosterol, independent on developmental stage. The naphthoquinone plumbagin has always showed to be the major component of all extracts. Naphthoquinones exhibited their highest content during floration, while the content of the two others components decreased during this stage, revealing an inverse profile. The chemical composition changed depending on the plant requirements.Plumbago scandens L. é uma espécie brasileira tropical/subtropical que ocorre ao longo da costa. Quimicamente, é principalmente representada por naftoquinonas, flavonóides, terpenóides e esteróides. objetivo do presente trabalho é estudar mudanças quantitativas da produção metabólica nas raízes de Plumbago scandens durante diferentes estágios de desenvolvimento fisiológico, relativos à floração. Os resultados indicaram a presença de quatro substâncias nos extratos: plumbagina, epi-isoshinanolona, ácido palmítico e sitosterol, independente do estágio de desenvolvimento. A naftoquinona plumbagina tem sempre mostrado ser o componente majoritário de todos os extratos. Naftoquinonas exibiram seus maiores conteúdos durante a floração, enquanto o conteúdo dos dois outros componentes decresceu durante este estágio, revelando um perfil inverso. A composição química modificou dependendo das necessidades da planta.

  8. 绿豆根边缘细胞发育特性%Biological Characters of Root Border Cell Development in Phaseolus radiatus

    Institute of Scientific and Technical Information of China (English)

    姜华; 王亚男; 何兵; 王煜; 马丹炜

    2012-01-01

    以东北绿豆为试验材料,采用琼脂悬空培养法,研究了绿豆边缘细胞的发育特性.结果表明:绿豆根尖发育初期根边缘细胞呈球形,随着根尖伸长逐渐发育形成椭圆形、长椭圆形和长条形;发育过程中,根边缘细胞具有较高的存活率,在根长大于10 mm后根边缘细胞的存活率均在70%~80%之间并趋于稳定;在根长为25~30 mm时根边缘细胞数目达到最大值(约13000个);根冠果胶甲基酯酶(PME)活性在根长5 mm时达到最高值(1.486H+ μmol·root cap-1·h-1),此后随着根的伸长,根冠PME活性在1.107~1.256 H+ μmol·root cap-1·h-1间变化并趋于稳定.%Northeast mung bean (.Phaseolus radiatus) as materials were used to study development characteristics of border cells by suspended culture with agar pour plate. The results showed that bean border cells were spherical shape with early development,and develop into oval shape,long oval shape and strip shape with growth gradually. The root border cells have high viability in development process and the viability were at 70%—80% and tended to be stable when the root length was greater than 10 mm;The number of root border cells reached maximum (about 13 000) when the root length was 25 ~30 mmj Pectin methylesterase activity of root cap reached the highest valued. 486 H+ fitnol · root cap-1 · h-1) with 5 mm root length,then changed in 1. 107~1. 256 H+μimol · root cap-1 · h-1 and tended to be stable with the root elongation.

  9. Comparative RNA-Seq Analysis Reveals That Regulatory Network of Maize Root Development Controls the Expression of Genes in Response to N Stress.

    Science.gov (United States)

    He, Xiujing; Ma, Haixia; Zhao, Xiongwei; Nie, Shujun; Li, Yuhua; Zhang, Zhiming; Shen, Yaou; Chen, Qi; Lu, Yanli; Lan, Hai; Zhou, Shufeng; Gao, Shibin; Pan, Guangtang; Lin, Haijian

    2016-01-01

    Nitrogen (N) is an essential nutrient for plants, and it directly affects grain yield and protein content in cereal crops. Plant root systems are not only critical for anchorage in the soil, but also for N acquisition. Therefore, genes controlling root development might also affect N uptake by plants. In this study, the responses of nitrogen on root architecture of mutant rtcs and wild-type of maize were investigated by morphological and physiological analysis. Subsequently, we performed a comparative RNA-Seq analysis to compare gene expression profiles between mutant rtcs roots and wild-type roots under different N conditions. We identified 786 co-modulated differentially expressed genes (DEGs) related to root development. These genes participated in various metabolic processes. A co-expression cluster analysis and a cis-regulatory motifs analysis revealed the importance of the AP2-EREBP transcription factor family in the rtcs-dependent regulatory network. Some genotype-specific DEGs contained at least one LBD motif in their promoter region. Further analyses of the differences in gene transcript levels between rtcs and wild-type under different N conditions revealed 403 co-modulated DEGs with distinct functions. A comparative analysis revealed that the regulatory network controlling root development also controlled gene expression in response to N-deficiency. Several AP2-EREBP family members involved in multiple hormone signaling pathways were among the DEGs. These transcription factors might play important roles in the rtcs-dependent regulatory network related to root development and the N-deficiency response. Genes encoding the nitrate transporters NRT2-1, NAR2.1, NAR2.2, and NAR2.3 showed much higher transcript levels in rtcs than in wild-type under normal-N conditions. This result indicated that the LBD gene family mainly functions as transcriptional repressors, as noted in other studies. In summary, using a comparative RNA-Seq-based approach, we identified

  10. Comparative RNA-Seq Analysis Reveals That Regulatory Network of Maize Root Development Controls the Expression of Genes in Response to N Stress.

    Directory of Open Access Journals (Sweden)

    Xiujing He

    Full Text Available Nitrogen (N is an essential nutrient for plants, and it directly affects grain yield and protein content in cereal crops. Plant root systems are not only critical for anchorage in the soil, but also for N acquisition. Therefore, genes controlling root development might also affect N uptake by plants. In this study, the responses of nitrogen on root architecture of mutant rtcs and wild-type of maize were investigated by morphological and physiological analysis. Subsequently, we performed a comparative RNA-Seq analysis to compare gene expression profiles between mutant rtcs roots and wild-type roots under different N conditions. We identified 786 co-modulated differentially expressed genes (DEGs related to root development. These genes participated in various metabolic processes. A co-expression cluster analysis and a cis-regulatory motifs analysis revealed the importance of the AP2-EREBP transcription factor family in the rtcs-dependent regulatory network. Some genotype-specific DEGs contained at least one LBD motif in their promoter region. Further analyses of the differences in gene transcript levels between rtcs and wild-type under different N conditions revealed 403 co-modulated DEGs with distinct functions. A comparative analysis revealed that the regulatory network controlling root development also controlled gene expression in response to N-deficiency. Several AP2-EREBP family members involved in multiple hormone signaling pathways were among the DEGs. These transcription factors might play important roles in the rtcs-dependent regulatory network related to root development and the N-deficiency response. Genes encoding the nitrate transporters NRT2-1, NAR2.1, NAR2.2, and NAR2.3 showed much higher transcript levels in rtcs than in wild-type under normal-N conditions. This result indicated that the LBD gene family mainly functions as transcriptional repressors, as noted in other studies. In summary, using a comparative RNA-Seq-based approach

  11. Effects of Media and IBA Concentrations on Rooting of Rhododendron fortunei for Cutting Propagation%基质和IBA浓度对云锦杜鹃扦插生根的影响

    Institute of Scientific and Technical Information of China (English)

    王书胜; 单文; 张乐华; 杜有新; 李晓花; 王凯红

    2015-01-01

    concentration on rooting parameters of R. fortunei,i. e. percentages of callus formation,rotting rate,rooting rate, and retaining rate of old leaves,number of total roots and number of adventitious roots,length of longest adventitious root, width of root system. And then we comprehensively evaluated the effects on rooting of each treatment combination by subordinate function analysis. [Result]The results showed that the effects of rooting medium and IBA concentration were highly significant (P<0. 01) for all measured parameters,and the influencing intensity of rooting medium was stronger than that of IBA concentration. The interaction of rooting medium and IBA concentration was highly significant only for four root development parameters including the number of total roots,number of adventitious roots,length of the longest adventitious root and root width. Among the six types of rooting media,the pure river sand medium produced extremely positive effects on most parameters except on length of the longest adventitious root and root width. The peat + perlite (4∶1) medium produced the highest callusing percentage,length of the longest adventitious root and root width,with less effect of other parameters than those of pure river sand medium. The rooting effects of the other four media decreased as the proportion of forest soil increased,and the pure forest soil medium showed the worst effect for all parameters. As to the four IBA concentrations,the best callusing and rotting percentages were observed at 100 mg·L -1 treatment,and with increase of IBA concentration,callusing percentage decreased significantly and rotting percentage increased. Rooting rate and retaining rate of old leaves were the highest at 200 mg·L -1 treatment,and decreased gradually as IBA concentration became higher. The number of total roots and adventitious roots,length of longest adventitious root and root width showed no significant difference among 100 ,200 and 400 mg·L -1 treatments and all these were

  12. Development of a 2D laser ablation inductively coupled plasma mass spectrometry mapping procedure for mercury in maize (Zea mays L.) root cross-sections

    Energy Technology Data Exchange (ETDEWEB)

    Debeljak, Marta [Analytical Chemistry Laboratory, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana (Slovenia); Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna Pot 111, SI-1000 Ljubljana (Slovenia); Elteren, Johannes T. van, E-mail: elteren@ki.si [Analytical Chemistry Laboratory, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana (Slovenia); Vogel-Mikuš, Katarina [Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna Pot 111, SI-1000 Ljubljana (Slovenia)

    2013-07-17

    Graphical abstract: -- Highlights: •LA-ICP-MS mapping to study the distribution of Hg in plant root cross-sections. •Sorption of LA-generated Hg vapour leads to serious memory effects. •Spot analysis with a delay time of 10 s in between spots alleviates memory effects. •Ablation straight through the sample simplifies calibration. •Hg{sup 2+} does not cross the endodermal root barrier of maize plants. -- Abstract: A LA-ICP-MS method based on a 213 nm Nd:YAG laser and a quadrupole ICP-MS has been developed for mapping of mercury in root cross-sections of maize (Zea mays L.) to investigate the mechanism of mercury uptake from soil and its potential translocation to the edible parts. Conventional rastering was found to be unusable due to sorption of mercury onto the internal parts of the LA device, giving rising to memory effects resulting in serious loss of resolution and inaccurate quantification. Spot analysis on a virtual grid on the surface of the root sections using washout times of 10 s in between spots greatly alleviated problems related to these memory effects. By ablating straight through the root sections on a poly(methyl methacrylate) support the calibration process was simplified as internal standardization and matrix-matching could be circumvented. Mercury-spiked freeze-drying embedding medium, sectioned similarly to the root sections, was used for the preparation of the standards. Standards and root sections were subjected to spot analysis using the following operational parameters: beam diameter, 15 μm; laser fluence, 2.5 J cm{sup −2}; repetition rate, 20 Hz; dwell time, 1 s; acquisition time, 0.1 s. The mercury peaks for standards and roots sections could be consistently integrated for quantification and construction of the 2D mercury maps for the root sections. This approach was successfully used to investigate the mercury distribution in root sections of maize grown in soil spiked to a level of 50 mg kg{sup −1} DW HgCl{sub 2}. It was

  13. Unraveling the intricate nexus of molecular mechanisms governing rice root development: OsMPK3/6 and auxin-cytokinin interplay.

    Directory of Open Access Journals (Sweden)

    Pallavi Singh

    Full Text Available The root system is an imperative component of a plant, involved in water and nutrient acquisition from the soil. Any subtle change in the root system may lead to drastic changes in plant productivity. Both auxin and cytokinin are implicated in regulating various root developmental aspects. One of the major signaling cascades facilitating various hormonal and developmental allocations is the Mitogen Activated Protein Kinase (MAPK cascade. Innumerable efforts have been made to unravel the complex nexus involved in rice root development. In spite of a plethora of studies, a comprehensive study aiming to decipher the plausible cross-talk of MAPK signaling module with auxin and cytokinin signaling components in rice is missing. In the present study, extensive phenomics analysis of different stages of rice roots; transcript profiling by qRT-PCR of entire gene family of MAPK, MAPKK and PIN genes; as well as protein level and activity of potential MAPKs was investigated using western and immuno kinase assays both on auxin and cytokinin treatment. The above study led to the identification of various novel rice root specific phenotypic traits by using GiA roots software framework. High expression profile of OsMPK3/6, OsMKK4/5 and OsPIN 1b/9 and their marked transcript level modulation in response to both auxin and cytokinin was observed. Finally, the protein levels and activity assay further substantiated our present findings. Thus, OsMPK3/6-OsMKK4/5 module is elucidated as the putative, key player in auxin-cytokinin interaction augmenting their role by differentially regulating the expression patterns of OsPIN 1b/9 in root development in rice.

  14. Screening conditions of adventitious bud induction and plantlet regeneration for Cunninghamia lanceolata%杉木茎段不定芽诱导及植株再生条件筛选

    Institute of Scientific and Technical Information of China (English)

    莫雅芳; 戴勤; 谭玲; 苏治南; 卢亮; 杨梅

    2013-01-01

    [目的]探索广西杉木快繁技术,为杉木组织培养和种苗供应提供参考依据.[方法]以杉木优良树种基部枝条为试验材料,进行茎段外植体消毒、不定芽诱导及植株再生研究.[结果]以75%酒精处理30 s+0.1%升汞消毒6min的效果较理想,污染率为30%;初代培养基为1/2MS+NAA 0.2 mg/L+6-BA 0.6 mg/L,第8d即有芽萌动,诱导率可达47%;继代培养基1/2MS +IBA 0.3 mg/L+6-BA 0.4 mg/L中加入蔗糖30 g/L,25 d腋芽增殖倍数可达3.4倍;1/4MS+IBA 0.15mg/L+NAA 0.075 mg/L对杉木生根诱导效果较好,生根率为52%.[结论],杉木外植体用75%酒精和0.1%升汞消毒6min效果较理想,适当减少培养基中矿质元素有利于杉木外殖体芽的诱导和试管苗的增殖生长,NAA可促进试管苗生根.%[Objective]Conditions of the adventitious bud induction and plant regeneration for Cunninghamia lanceolata were screened and rapid propagation techniques for Chinese fir in Guangxi was explored to provide references for supply and tissue culture of Chinese fir seedlings.[Method]Using base branches of superior Chinese fir species as testing materials,stem explant disinfection,adventitious bud induction and plant regeneration were the focal points in the current research.[Result] (1)The best disinfection method was treating stem explants with 75% ethanol for 30 s and 0.1% mercuric chloride for 6 min,which showed 30% contamination rate; (2)In the initial medium (1/2MS + NAA 0.2 mg/L + 6-BA 0.6 mg/L),the buds germinated on the 8th day with the induction rate of 47%; (3)In the optimum subculture medium (1/2MS + IBA 0.3 mg/L + 6-BA 0.6 mg/L + white sugar 30 g/L),axillary buds were multiplied by 3.4 times on the 25th day; (4)The induction effect was the best with the rooting rate of 52% in the rooting medium (1/4MS + IBA 0.15 mg/L + NAA 0.075 mg/L).[Conclusion]It was beneficial to the adventitious bud induction for Chinese fir with the initial medium (1/2MS + NAA 0.2 mg

  15. Ideal root architecture for phosphorus acquisition of plants under water and phosphorus coupled stresses: From simulation to application

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Under water and phosphorus (P) coupledstresses, root architecture may be related to P acquisition efficiency of plants. Understanding the relationship between root architecture and P acquisition efficiency may provide basic information for improving P acquisition efficiency of plants. In the present study, we quantitatively described the effects of root architecture on P acquisition efficiency by computer simulation together with controlled biological experiments so as to determine an ideal root architecture for efficient P acquisition under water and P coupled stresses.Our results indicate that under given soil water conditions,the ideal root architecture for P acquisition efficiency of a tap root plant (as represented by common bean) is an "umbrella-shape'' root system whose basal roots tend to be shallow in the P-rich topsoil and tap roots tend to be deep for water in the subsoil. Meanwhile, the ideal root architecture for a fibrous root plant (as represented by upland rice) is a "beard-shape" root system with the moderately dispersed yet uniformly distributed adventitious and lateral roots so as to keep most roots in the topsoil for P and a few roots in the subsoil for water.

  16. A Novel Sucrose-Regulatory MADS-Box Transcription Factor GmNMHC5 Promotes Root Development and Nodulation in Soybean (Glycine max [L.] Merr.

    Directory of Open Access Journals (Sweden)

    Wei Liu

    2015-08-01

    Full Text Available The MADS-box protein family includes many transcription factors that have a conserved DNA-binding MADS-box domain. The proteins in this family were originally recognized to play prominent roles in floral development. Recent findings, especially with regard to the regulatory roles of the AGL17 subfamily in root development, have greatly broadened their known functions. In this study, a gene from soybean (Glycine max [L.] Merr., GmNMHC5, was cloned from the Zigongdongdou cultivar and identified as a member of the AGL17 subfamily. Real-time fluorescence quantitative PCR analysis showed that GmNMHC5 was expressed at much higher levels in roots and nodules than in other organs. The activation of expression was first examined in leaves and roots, followed by shoot apexes. GmNMHC5 expression levels rose sharply when the plants were treated under short-day conditions (SD and started to pod, whereas low levels were maintained in non-podding plants under long-day conditions (LD. Furthermore, overexpression of GmNMHC5 in transgenic soybean significantly promoted lateral root development and nodule building. Moreover, GmNMHC5 is upregulated by exogenous sucrose. These results indicate that GmNMHC5 can sense the sucrose signal and plays significant roles in lateral root development and nodule building.

  17. The Nitrification Inhibitor Methyl 3-(4-Hydroxyphenyl)Propionate Modulates Root Development by Interfering with Auxin Signaling via the NO/ROS Pathway.

    Science.gov (United States)

    Liu, Yangyang; Wang, Ruling; Zhang, Ping; Chen, Qi; Luo, Qiong; Zhu, Yiyong; Xu, Jin

    2016-07-01

    Methyl 3-(4-hydroxyphenyl)propionate (MHPP) is a root exudate that functions as a nitrification inhibitor and as a modulator of the root system architecture (RSA) by inhibiting primary root (PR) elongation and promoting lateral root formation. However, the mechanism underlying MHPP-mediated modulation of the RSA remains unclear. Here, we report that MHPP inhibits PR elongation in Arabidopsis (Arabidopsis thaliana) by elevating the levels of auxin expression and signaling. MHPP induces an increase in auxin levels by up-regulating auxin biosynthesis, altering the expression of auxin carriers, and promoting the degradation of the auxin/indole-3-acetic acid family of transcriptional repressors. We found that MHPP-induced nitric oxide (NO) production promoted reactive oxygen species (ROS) accumulation in root tips. Suppressing the accumulation of NO or ROS alleviated the inhibitory effect of MHPP on PR elongation by weakening auxin responses and perception and by affecting meristematic cell division potential. Genetic analysis supported the phenotype described above. Taken together, our results indicate that MHPP modulates RSA remodeling via the NO/ROS-mediated auxin response pathway in Arabidopsis. Our study also revealed that MHPP significantly induced the accumulation of glucosinolates in roots, suggesting the diverse functions of MHPP in modulating plant growth, development, and stress tolerance in plants.

  18. The language situation in Sub-Saharan Africa : Historical roots, measurement, and development impacts

    NARCIS (Netherlands)

    Buzasi, K.

    2015-01-01

    The broader aim of this thesis is to contribute to the literature seeking the role of languages in determining the socio-economic development in Sub-Saharan Africa. The four chapters are related to three issues: linguistic diversity measurement, the role of languages other than communication, and th

  19. Developing Grass Roots Writing Resources: A Novel Approach to Writing within the Social Work Discipline

    Science.gov (United States)

    Kilgore, Christopher D.; Cronley, Courtney; Amey, Beth

    2013-01-01

    In this case study, we report on the development of a writing-specialist position, the "Writing Resource Coordinator (WRC)", in a school of social work at a large state university in the southern USA. Such programs are facing increasing budgetary pressures at the same time as their growing enrollments strain available resources. Students…

  20. Direct Adventitious Bud Induction and Plant Regeneration of Rosa hybrida Samantha

    Institute of Scientific and Technical Information of China (English)

    GAO Li-ping; BAO Man-zhu

    2005-01-01

    Effect of explant, site of leaflet, induction period in the dark and combinations of plant growth regulators on direct adventitious bud induction and plant regeneration of Rosa hybrida Samantha was investigated. The results showed that after an induction period of 8 d on MS medium with 1.5 mg L-1 TDZ and 0.05 mg L-1 NAA in the dark and a subculture on MS medium with 0.5 mg L-1 BA and 0.01 mg L-1 NAA under light, the best plant regeneration was obtained and the regeneration frequencies of leaflets and petioles were 51.8 and 10% respectively. There was no significant difference in regeneration ability between leaflets at different sites of the compound leaves, longer time of induction in the dark or high concentration of auxin would cause callus formation, which was disadvantageous for shoot regeneration, and the regeneration frequency was significantly reduced. This regeneration system could be applied for genetic transformation of this cultivar in the future.

  1. An adventitious interaction of filamin A with RhoGDI2(Tyr153Glu)

    Science.gov (United States)

    Song, Mia; He, Qianjing; Berk, Benjamin-Andreas; Hartwig, John H.; Stossel, Thomas P.; Nakamura, Fumihiko

    2015-01-01

    Filamin A (FLNA) is an actin filament crosslinking protein with multiple intracellular binding partners. Mechanical force exposes cryptic FLNA binding sites for some of these ligands. To identify new force-dependent binding interactions, we used a fusion construct composed of two FLNA domains, one of which was previously identified as containing a force-dependent binding site as a bait in a yeast two-hybrid system and identified the Rho dissociation inhibitor 2 (RhoGDI2) as a potential interacting partner. A RhoGDI2 truncate with 81 N-terminal amino acid residues and a phosphomimetic mutant, RhoGDI(Tyr153Glu) interacted with the FLNA construct. However, neither wild-type or full-length RhoGDI2 phosphorylated at Y153 interacted with FLNA. Our interpretation of these contradictions is that truncation and/or mutation of RhoGDI2 perturbs its conformation to expose a site that adventitiously binds FLNA and is not a bona-fide interaction. Therefore, previous studies reporting that a RhoGDI(Y153E) mutant suppresses the metastasis of human bladder cancer cells must be reinvestigated in light of artificial interaction of this point mutant with FLNA. PMID:26707877

  2. Redesigning finance towards job-creating long-term development : some regulatory roots

    OpenAIRE

    Ülgen, Faruk

    2013-01-01

    22 p.; Financial development is usually assumed to play a key role in the evolution of modern capitalism. A substantial strand of the academic literature, referring to Schumpeterian Creative Destruction, points out this role in the process of technology-based growth and puts the emphasis on the contribution of new financial techniques and products to the funding of global mergers but also to the financing of small enterprises and start-ups in innovative sectors. It is argued that growth-enhan...

  3. The development of Swedish business journalism : Historical roots of an organisational field

    OpenAIRE

    Grafström, Maria

    2006-01-01

    Contemporary Swedish business journalism is an established organisational field with shared practice within and across organisations. Using a historical perspective, this dissertation investigates the early formation of this field and the formation of a shared meaning system for business journalism. Addressing the question of how and why the field emerged, the study contributes to institutional approaches in organisational analysis and theories about field development. Drawing on a qualitativ...

  4. Relation of Root Growth of Rice Seedling with Nutrition and Water Use Efficiency Under Different Water Supply Conditions

    Institute of Scientific and Technical Information of China (English)

    ZHENG Bing-song; JIANG De-an; WU Ping; WENG Xiao-yan; LU Qing; WANG Ni-yan

    2006-01-01

    Water deficiency is one of the primary yield-limiting factors in rice. In plants, the nutrition and water use efficiency depend on root growth efficiency under different water supply conditions (WSC). Three rice genotypes, Azucena (an upland japonica),IR1552 (a lowland indica) and Jia 9522 (a lowland japonica), were grown under different WSC with 0 cm (submerged), 40 cm and 80cm groundwater levels below the soil surface to investigate the root parameters, water use efficiency, nitrogen, phosphorous and potassium contents, net photosynthetic rate and transpiration rate of the rice plant. The relative parameters were defined as the ratio of the parameters under submerged conditions (0 cm groundwater level below soil surface) to these under upland conditions (40 cm and 80 cm groundwater levels below soil surface). The results indicated that different genotypes showed different relative root parameters and relative nutrition content and water use efficiency under different WSC. The length and number of adventitious root are more important than seminal root length in water and nutrition uptake, and maintaining the grain yield and increasing dry matter,but the adventitious root number could not be served as an index for screening drought-resistant genotypes. Furthermore, different drought-resistant genotypes have been also found, and Azucena was resistant to drought, IR1552 sensitive to drought and Jia 9522neither sensitive nor resistant to drought.

  5. An evidence-based toolkit for the development of effective and sustainable root cause analysis system safety solutions.

    Science.gov (United States)

    Hettinger, A Zachary; Fairbanks, Rollin J; Hegde, Sudeep; Rackoff, Alexandra S; Wreathall, John; Lewis, Vicki L; Bisantz, Ann M; Wears, Robert L

    2013-01-01

    Root cause analysis (RCA) after adverse events in healthcare is a standard practice at many institutions. However, healthcare has failed to see a dramatic improvement in patient safety over the last decade. In order to improve the RCA process, this study used systems safety science, which is based partly on human factors engineering principles and has been applied with success in other high-risk industries like aviation. A multi-institutional dataset of 334 RCA cases and 782 solutions was analyzed using qualitative methods. A team of safety science experts developed a model of 13 RCA solutions categories through an iterative process, using semi-structured interview data from 44 frontline staff members from 7 different hospital-based unit types. These categories were placed in a model and toolkit to help guide RCA teams in developing sustainable and effective solutions to prevent future adverse events. This study was limited by its retrospective review of cases and use of interviews rather than clinical observations. In conclusion, systems safety principles were used to develop guidelines for RCA teams to promote systems-level sustainable and effective solutions for adverse events.

  6. Study on Construction of Service-oriented Government at Grass-roots Level and Development of Farmers’ Professional Cooperatives

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Features of farmers’ professional cooperatives in China are introduced.The establishment of these organizations is spontaneous.Their operation shows self-government.And their targets are highly pertinent.Then,I analyze the existing problems in farmers’ professional cooperatives and vacancy of government functions.These cooperatives are single in content,narrow in service field,not scientific in management mode,and low in efficiency.In addition,government policy support is not put in place for these cooperatives.In view of these situations,firstly,it is proposed to speed up construction of service-oriented government at grass-roots level and promote development of farmers’ professional cooperatives.Secondly,it is suggested to set up awareness of service-oriented government and enhance guidance and service for farmers’ professional cooperatives.Thirdly,we should increase financial support and guide these organizations to achieve a benign development.Fourthly,we should strengthen propaganda to raise popularity and influence power of these organizations.Fifthly,it is recommended to make clear the guidance and leading functions of regional supply and marketing cooperatives to raise service efficiency.Finally,we should establish scientific evaluation and incentive system to push forward healthy development of farmers’ professional cooperatives.

  7. Activities of Peroxidase、IAA-oxidase and Catalase in the Development of Adventitious Root of Paulownia foutunei(Seem.) Hemsl%白花泡桐根分化过程中过氧化物酶、IAA氧化酶和过氧化氢酶的变化

    Institute of Scientific and Technical Information of China (English)

    韦素玲

    2001-01-01

    为了解过氧化物酶、IAA氧化酶和过氧化氢酶在植物不定根分化、发育过程中的作用,在实验室内分析测定白花泡桐[Paulownia foutunei(Seem.)Hemsl]不定根分化过程中过氧化物酶、IAA氧化酶和过氧化氢酶活性的变化.结果表明:过氧化物酶在根分化0 d~2 d的活性下降37.6%,随后逐步上升;IAA氧化酶活性在0 d~2 d内迅速下降了52.6%,随后逐步上升;过氧化氢酶的活性在不定根分化过程中逐步上升,0 d~4 d酶活性从5.1上升到10.5,从第4天开始活性增加减慢.

  8. Latin American social medicine: roots, development during the 1990s, and current challenges.

    Science.gov (United States)

    Tajer, Débora

    2003-12-01

    Latin American social medicine arose during the 1950s and 1960s, drawing its inspiration from the social movements that emerged in France, Germany, and England in the mid-19th century. The Latin American movement of social medicine has clear ideological goals. It is organized around the Latin American Association of Social Medicine, which was founded in 1984 and is regarded as a social, political, and academic movement. This article takes a historical perspective and presents the reasons for the emergence and identity of the association, focusing on the main developments and contributions of this movement from the 1990s until the present time.

  9. Dynamic stall development in the near-root region of a model wind turbine blade

    Science.gov (United States)

    Melius, Matthew; Cal, Raul Bayoan; Mulleners, Karen

    2014-11-01

    The dynamic behavior of atmospheric flows create highly variable operational conditions which affect the life expectancy of the turbine components and the power output of the turbine. To gain insight into the unsteady aerodynamics of wind turbine blades, wind tunnel experiments were conducted with a scaled three-dimensional NREL 5MW wind turbine blade model in the 2.2 m × 1.8 m cross-section closed loop wind tunnel DLR in Göttingen. The development of dynamic stall in response to a sudden change in the blades angle of attack are studied by means of time-resolved stereoscopic PIV in span-wisely distributed planes capturing the suction side of the blade. The change in angle of attack was obtained by varying the blade pitch angle to simulate a sudden change in wind speed or pitch angle regulation. Resulting time scales associated with flow separation and reattachment are determined at different radial positions ranging from r / R = 0 . 19 to r / R = 0 . 38 . The influence of the three-dimensionality of the blade geometry on the corresponding aerodynamic effects is captured by analyzing the radial flow component in neighboring measurement fields during stall development.

  10. CNS-derived glia ensheath peripheral nerves and mediate motor root development.

    Science.gov (United States)

    Kucenas, Sarah; Takada, Norio; Park, Hae-Chul; Woodruff, Elvin; Broadie, Kendal; Appel, Bruce

    2008-02-01

    Motor function requires that motor axons extend from the spinal cord at regular intervals and that they are myelinated by Schwann cells. Little attention has been given to another cellular structure, the perineurium, which ensheaths the motor nerve, forming a flexible, protective barrier. Consequently, the origin of perineurial cells and their roles in motor nerve formation are poorly understood. Using time-lapse imaging in zebrafish, we show that perineurial cells are born in the CNS, arising as ventral spinal-cord glia before migrating into the periphery. In embryos lacking perineurial glia, motor neurons inappropriately migrated outside of the spinal cord and had aberrant axonal projections, indicating that perineurial glia carry out barrier and guidance functions at motor axon exit points. Additionally, reciprocal signaling between perineurial glia and Schwann cells was necessary for motor nerve ensheathment by both cell types. These insights reveal a new class of CNS-born glia that critically contributes to motor nerve development.

  11. GmEXPB2, a Cell Wall β-Expansin, Affects Soybean Nodulation through Modifying Root Architecture and Promoting Nodule Formation and Development.

    Science.gov (United States)

    Li, Xinxin; Zhao, Jing; Tan, Zhiyuan; Zeng, Rensen; Liao, Hong

    2015-12-01

    Nodulation is an essential process for biological nitrogen (N2) fixation in legumes, but its regulation remains poorly understood. Here, a β-expansin gene, GmEXPB2, was found to be critical for soybean (Glycine max) nodulation. GmEXPB2 was preferentially expressed at the early stage of nodule development. β-Glucuronidase staining further showed that GmEXPB2 was mainly localized to the nodule vascular trace and nodule vascular bundles, as well as nodule cortical and parenchyma cells, suggesting that GmEXPB2 might be involved in cell wall modification and extension during nodule formation and development. Overexpression of GmEXPB2 dramatically modified soybean root architecture, increasing the size and number of cortical cells in the root meristematic and elongation zones and expanding root hair density and size of the root hair zone. Confocal microscopy with green fluorescent protein-labeled rhizobium USDA110 cells showed that the infection events were significantly enhanced in the GmEXPB2-overexpressing lines. Moreover, nodule primordium development was earlier in overexpressing lines compared with wild-type plants. Thereby, overexpression of GmEXPB2 in either transgenic soybean hairy roots or whole plants resulted in increased nodule number, nodule mass, and nitrogenase activity and thus elevated plant N and phosphorus content as well as biomass. In contrast, suppression of GmEXPB2 in soybean transgenic composite plants led to smaller infected cells and thus reduced number of big nodules, nodule mass, and nitrogenase activity, thereby inhibiting soybean growth. Taken together, we conclude that GmEXPB2 critically affects soybean nodulation through modifying root architecture and promoting nodule formation and development and subsequently impacts biological N2 fixation and growth of soybean.

  12. Effects of postnatal anti-NGF on the development of CGRP-IR neurons in the dorsal root ganglion.

    Science.gov (United States)

    Tonra, J R; Mendell, L M

    1998-03-23

    Experiments were undertaken to examine anatomical correlates of physiological effects of rabbit sera raised against nerve growth factor (anti-NGF) on nociceptive afferents. This antiserum has been shown to deplete the population of A-delta high threshold mechanoreceptors and to reduce neurogenic vasodilatation. Because numerous studies implicate calcitonin gene related peptide (CGRP)-containing sensory neurons in these effects, immunocytochemical and anatomical techniques were used to examine the normal development of CGRP-immunoreactive (-IR) neurons in the dorsal root ganglion (DRG) of rats from 13 days to 19 weeks of age, and to compare this to the development in rats treated neonatally (postnatal days 2-14) with anti-NGF. In controls the rate of increase in the mean diameter of CGRP-IR cells was substantially greater between 13 days and 5 weeks of age than it was between 5 weeks and 19 weeks, in contrast to CGRP-negative neurons whose rate of growth remained relatively constant. Anti-NGF had no significant effect on growth rate, but rats treated with anti-NGF exhibited a reduced proportion of CGRP-IR neurons at 5 weeks. This deficit was reversed by 19 weeks unlike the physiological changes. These results indicate independent regulation of CGRP expression and nociceptor physiology by NGF.

  13. Reduction of the cytosolic phosphoglucomutase in Arabidopsis reveals impact on plant growth, seed and root development, and carbohydrate partitioning.

    Directory of Open Access Journals (Sweden)

    Irina Malinova

    Full Text Available Phosphoglucomutase (PGM catalyses the interconversion of glucose 1-phosphate (G1P and glucose 6-phosphate (G6P and exists as plastidial (pPGM and cytosolic (cPGM isoforms. The plastidial isoform is essential for transitory starch synthesis in chloroplasts of leaves, whereas the cytosolic counterpart is essential for glucose phosphate partitioning and, therefore, for syntheses of sucrose and cell wall components. In Arabidopsis two cytosolic isoforms (PGM2 and PGM3 exist. Both PGM2 and PGM3 are redundant in function as single mutants reveal only small or no alterations compared to wild type with respect to plant primary metabolism. So far, there are no reports of Arabidopsis plants lacking the entire cPGM or total PGM activity, respectively. Therefore, amiRNA transgenic plants were generated and used for analyses of various parameters such as growth, development, and starch metabolism. The lack of the entire cPGM activity resulted in a strongly reduced growth revealed by decreased rosette fresh weight, shorter roots, and reduced seed production compared to wild type. By contrast content of starch, sucrose, maltose and cell wall components were significantly increased. The lack of both cPGM and pPGM activities in Arabidopsis resulted in dwarf growth, prematurely die off, and inability to develop a functional inflorescence. The combined results are discussed in comparison to potato, the only described mutant with lack of total PGM activity.

  14. Stand establishment, root development and yield of winter wheat as affected by tillage and straw mulch in the water deifcit hilly region of southwestern China

    Institute of Scientific and Technical Information of China (English)

    LI Chao-su; LI Jin-gang; TANG Yong-lu; WU Xiao-li; WU Chun; HUANG Gang; ZENG Hui

    2016-01-01

    Good crop stand establishment and root system development are essential for optimum grain yield of dryland wheat (Triti-cum aestivumL.). At present, little is known about the effect of tilage and straw mulch on the root system of wheat under dryland areas in southwestern China. The aim of this study was to evaluate the effect of three tilage treatments (no-til, NT; rotary til, RT; conventional til, CT) and two crop residue management practices (straw mulch, ML; non-straw mulch, NML) on stand establishment, root growth and grain yield of wheat. NT resulted in lower soil cover thickness for the wheat seed, higher number of uncovered seeds, lower percentage of seedling-less ridges and lower tiler density compared to RT and CT; ML resulted in higher tiler density compared to NML. Straw mulching resulted in more soil water content and root length density (RLD) at most of the growth stages and soil depths. The maximum RLD, root surface area density and root dry matter density were obtained under NT. In the topmost 10 cm soil layer, higher RLD values were found under NT than those under RT and CT. There were no signiifcant differences in the yield or yield components of wheat among the tilage treatments in 2011–2012, but NT resulted in a signiifcant higher yield compared to RT and CT in 2012–2013. Grain yield was signiifcantly higher in ML compared to in NML. A strong relationship was observed between the water-use efifciency and the grain yield. Both NT and ML proved beneifcial for wheat in term of maintaining higher tiler density, better soil water status and root growth, leading to a higher grain yield and enhanced water-use efifciency, especialy in a low rainfal year.

  15. Development of a novel antimicrobial dental resin root surface treatment for compromised open flap debridement patients

    Science.gov (United States)

    Battle-Siatita, Shelrethia

    Heating, ventilation, and air conditioning systems are widely used in buildings to provide occupants with conditioned air and acceptable indoor air quality. The chilled water system is one of the most commonly used HVAC systems in the both commercial and industrial buildings. These systems are currently used to provide thermal comfort for a wide array of building types, sizes, and in different climates. The design of these systems constitutes a large impact on the energy usage and operating cost of buildings they serve. Buildings stand for a substantial part of the total energy consumption in the Unites States, and with an increase focus on cost reductions and energy savings, it is necessary to use intelligent and energy-saving models. The ability to accurately predict the performance of these systems is integral to designing more energy efficient and sustainable building systems. In this thesis, the modeling of a chilled water air handling unit using system identification methods is proposed. System identification is the procedure of building mathematical models of dynamic systems from measured data. Two MISO (Multiple Input-Single Output) models are created to find the supply air temperature and fan power of an investigated chilled water air handling unit. The models are identified following the black-box approach, and data for a span of five months is collected and pre-processed. The system identification models are then trained using the measured data. Different model structures along with various time delays and orders were then tested to determine the most optimal structure. The prediction results are later compared to the actual data using the mean square error and coefficient of variance. In addition, an optimization method is developed to automate the process of finding the best model structure that can produce the best accurate prediction against the actual data. The obtained results validate the use of system identification methodologies as an accurate

  16. Expression of the immunoglobulin superfamily cell adhesion molecules in the developing spinal cord and dorsal root ganglion.

    Science.gov (United States)

    Gu, Zirong; Imai, Fumiyasu; Kim, In Jung; Fujita, Hiroko; Katayama, Kei ichi; Mori, Kensaku; Yoshihara, Yoshihiro; Yoshida, Yutaka

    2015-01-01

    Cell adhesion molecules belonging to the immunoglobulin superfamily (IgSF) control synaptic specificity through hetero- or homophilic interactions in different regions of the nervous system. In the developing spinal cord, monosynaptic connections of exquisite specificity form between proprioceptive sensory neurons and motor neurons, however, it is not known whether IgSF molecules participate in regulating this process. To determine whether IgSF molecules influence the establishment of synaptic specificity in sensory-motor circuits, we examined the expression of 157 IgSF genes in the developing dorsal root ganglion (DRG) and spinal cord by in situ hybridization assays. We find that many IgSF genes are expressed by sensory and motor neurons in the mouse developing DRG and spinal cord. For instance, Alcam, Mcam, and Ocam are expressed by a subset of motor neurons in the ventral spinal cord. Further analyses show that Ocam is expressed by obturator but not quadriceps motor neurons, suggesting that Ocam may regulate sensory-motor specificity in these sensory-motor reflex arcs. Electrophysiological analysis shows no obvious defects in synaptic specificity of monosynaptic sensory-motor connections involving obturator and quadriceps motor neurons in Ocam mutant mice. Since a subset of Ocam+ motor neurons also express Alcam, Alcam or other functionally redundant IgSF molecules may compensate for Ocam in controlling sensory-motor specificity. Taken together, these results reveal that IgSF molecules are broadly expressed by sensory and motor neurons during development, and that Ocam and other IgSF molecules may have redundant functions in controlling the specificity of sensory-motor circuits.

  17. Root resorption

    DEFF Research Database (Denmark)

    Kjaer, Inger

    2014-01-01

    Introduction: This paper summarizes the different conditions, which have a well-known influence on the resorption of tooth roots, exemplified by trauma and orthodontic treatment. The concept of the paper is to summarize and explain symptoms and signs of importance for avoiding resorption during...... orthodontic treatment. The Hypothesis: The hypothesis in this paper is that three different tissue layers covering the root in the so-called periroot sheet can explain signs and symptoms of importance for avoiding root resorption during orthodontic treatment. These different tissue layers are; outermost...... processes provoked by trauma and orthodontic pressure. Inflammatory reactions are followed by resorptive processes in the periroot sheet and along the root surface. Evaluation of the Hypothesis: Different morphologies in the dentition are signs of abnormal epithelium or an abnormal mesodermal layer. It has...

  18. Soil compaction limits root development, radiation-use efficiency and yield of three winter wheat (Triticum aestivum L.) cultivars

    DEFF Research Database (Denmark)

    Andersen, Mathias Neumann; Munkholm, Lars Juhl; Nielsen, Anne Lisbeth

    2013-01-01

    precipitation, the impairment of root penetration resulted in a minor yield decrease of ca. 9% of grain yield in PAC-2 and ca. 8% of total dry matter (DM) in both compaction treatments. The latter was attributed to decreases in interception of light and to efficiency of light energy conversion into biomass....... The RUE was positively correlated with an estimated effective rooting depth across cultivars, while DM yield was not. This correlation probably was a result of restrictions on stomatal opening mediated by drought stress and abscisic acid produced in the root system in response to occasional soil drying....... Root-sourced signals, triggered in a direct response to soil compaction, may have contributed....

  19. A root submergence technique for pontic site development in fixed dental prostheses in the maxillary anterior esthetic zone

    OpenAIRE

    Choi, Sunyoung; Yeo, In-Sung; Kim, Sung-Hun; Lee, Jai-Bong; Cheong, Chan Wook; Han, Jung-Suk

    2015-01-01

    Purpose This case report discusses the effect of a root submergence technique on preserving the periodontal tissue at the pontic site of fixed dental prostheses in the maxillary anterior aesthetic zone. Methods Teeth with less than ideal structural support for fixed retainer abutments were decoronated at the crestal bone level. After soft tissue closure, the final fixed dental prostheses were placed with the pontics over the submerged root area. Radiographic and clinical observations at the p...

  20. In vitro evaluation of the sealing ability of three newly developed root canal sealers: A bacterial microleakage study

    Science.gov (United States)

    Sobhani, Ehsan; Samadi-Kafil, Hossein; Pirzadeh, Ahmad; Jafari, Sanaz

    2016-01-01

    Background The purpose of this study was to compare the sealing ability of MTA Fillapex, Apatite Root Canal Sealer and AH26 sealers. Material and Methods The present in vitro study was carried out on 142 extracted single-rooted human mature teeth. The teeth were randomly divided into three experimental groups (n=44) and two control groups (n=5). Three root canal sealers were MTA Fillapex, Apatite Root Canal Sealer and AH26. The teeth in the control groups were either filled with no sealer or made completely impermeable. The root canals were prepared and obturated with gutta-percha and one of the sealers. The teeth were sterilized with ethylene oxide gas prior to the bacterial leakage assessment using Enterococcus faecalis. Leakage was evaluated every 24 hours for 90 days. Data were analyzed with descriptive statistical methods and chi-squared test. If the data were significant, a proper post hoc test was used. Statistical significance was set at P<0.05. Results The positive control specimens exhibited total bacterial penetration whilst the negative control specimens showed no evidence of bacterial penetration. At the end of the study, the analysis of microleakage with chi-squared test showed no significant differences between the experimental groups (P<0.05). The results of chi-squared test analyzing the pair-wise differences between the groups considering the numerical values for leakage day indicated the lowest leakage with AH26 and the highest with Apatite root sealer. Conclusions According to the results of the present study, sealing ability of AH26 was significantly higher than that of MTA Fillapex and Apatite Root Canal Sealer. Key words:Mineral Trioxide aggregate, root canal obturation, dental seal. PMID:27957271

  1. Novel approach to continuous adventitious respiratory sound analysis for the assessment of bronchodilator response

    Science.gov (United States)

    Fiz, José Antonio; Martínez-Rivera, Carlos; Torrents, Aurora; Ruiz-Manzano, Juan; Jané, Raimon

    2017-01-01

    Background A thorough analysis of continuous adventitious sounds (CAS) can provide distinct and complementary information about bronchodilator response (BDR), beyond that provided by spirometry. Nevertheless, previous approaches to CAS analysis were limited by certain methodology issues. The aim of this study is to propose a new integrated approach to CAS analysis that contributes to improving the assessment of BDR in clinical practice for asthma patients. Methods Respiratory sounds and flow were recorded in 25 subjects, including 7 asthma patients with positive BDR (BDR+), assessed by spirometry, 13 asthma patients with negative BDR (BDR-), and 5 controls. A total of 5149 acoustic components were characterized using the Hilbert spectrum, and used to train and validate a support vector machine classifier, which distinguished acoustic components corresponding to CAS from those corresponding to other sounds. Once the method was validated, BDR was assessed in all participants by CAS analysis, and compared to BDR assessed by spirometry. Results BDR+ patients had a homogenous high change in the number of CAS after bronchodilation, which agreed with the positive BDR by spirometry, indicating high reversibility of airway obstruction. Nevertheless, we also found an appreciable change in the number of CAS in many BDR- patients, revealing alterations in airway obstruction that were not detected by spirometry. We propose a categorization for the change in the number of CAS, which allowed us to stratify BDR- patients into three consistent groups. From the 13 BDR- patients, 6 had a high response, similar to BDR+ patients, 4 had a noteworthy medium response, and 1 had a low response. Conclusions In this study, a new non-invasive and integrated approach to CAS analysis is proposed as a high-sensitive tool for assessing BDR in terms of acoustic parameters which, together with spirometry parameters, contribute to improving the stratification of BDR levels in patients with

  2. Adventitial Tertiary Lymphoid Organs as Potential Source of MicroRNA Biomarkers for Abdominal Aortic Aneurysm.

    Science.gov (United States)

    Spear, Rafaelle; Boytard, Ludovic; Blervaque, Renaud; Chwastyniak, Maggy; Hot, David; Vanhoutte, Jonathan; Staels, Bart; Lemoine, Yves; Lamblin, Nicolas; Pruvot, François-René; Haulon, Stephan; Amouyel, Philippe; Pinet, Florence

    2015-05-18

    Abdominal aortic aneurysm (AAA) is an inflammatory disease associated with marked changes in the cellular composition of the aortic wall. This study aims to identify microRNA (miRNA) expression in aneurysmal inflammatory cells isolated by laser microdissection from human tissue samples. The distribution of inflammatory cells (neutrophils, B and T lymphocytes, mast cells) was evaluated in human AAA biopsies. We observed in half of the samples that adventitial tertiary lymphoid organs (ATLOs) with a thickness from 0.5 to 2 mm were located exclusively in the adventitia. Out of the 850 miRNA that were screened by microarray in isolated ATLOs (n = 2), 164 miRNAs were detected in ATLOs. The three miRNAs (miR-15a-3p, miR-30a-5p and miR-489-3p) with the highest expression levels were chosen and their expression quantified by RT-PCR in isolated ATLOs (n = 4), M1 (n = 2) and M2 macrophages (n = 2) and entire aneurysmal biopsies (n = 3). Except for the miR-30a-5p, a similar modulation was found in ATLOs and the two subtypes of macrophages. The modulated miRNAs were then evaluated in the plasma of AAA patients for their potential as AAA biomarkers. Our data emphasize the potential of miR-15a-3p and miR-30a-5p as biomarkers of AAA but also as triggers of ATLO evolution. Further investigations will be required to evaluate their targets in order to better understand AAA pathophysiology.

  3. OsGatB, the subunit of tRNA-dependent amidotransferase, is required for primary root development in rice

    Directory of Open Access Journals (Sweden)

    Cheng eQin

    2016-05-01

    Full Text Available A short-root rice mutant was isolated from an ethyl methane sulfonate-mutagenized library. From map-based cloning strategy, a point mutation, resulting in an amino acid change from proline to leucine, was identified in the fourth exon of a glutamyl-tRNA (Gln amidotransferase B subunit family protein (OsGatB, LOC_Os11g34210. This gene is an ortholog of Arabidopsis GatB and yeast PET112. GatB is a subunit of tRNA-dependent amidotransferase (AdT, an essential enzyme involved in Gln-tRNAGln synthesis in mitochondria. Although previous studies have described that cessation in mitochondrial translation is lethal at very early developmental stages in plants, this point mutation resulted in a non-lethal phenotype of smaller root meristem and shorter root cell length. In the root, OsGatB was predominantly expressed in the root tip and played an important role in cell division and elongation there. OsGatB was localized in the mitochondria, and mitochondrial structure and function were all affected in Osgatb root tip cells.

  4. Percutaneous ethanol sclerotherapy for recurrent adventitial cystic disease of external iliac vein after surgical treatment: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Ann, Jun Hyung; Kim, Jeong Ho; Byun, Sung Su; Kang, Jin Mo; Kim, Hyung Sik; Choi, Hye Young [Gachon University Gil Medical Center, Incheon (Korea, Republic of)

    2015-12-15

    Adventitial cystic disease (ACD) is a rare, but well-characterized vascular disease. It is most commonly seen in the popliteal artery, but it has also been reported in the venous system. The most commonly involved segment has been the common femoral vein; the disease resulted in luminal compromise and extremity swelling. We report here on a case of percutaneous aspiration and ethanol sclerotherapy for recurrent ACD after surgery of the external iliac vein in a 70-year-old man who presented with a painless swelling of his left leg.

  5. Transcriptomic changes during maize roots development responsive to Cadmium (Cd) pollution using comparative RNAseq-based approach

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Hua [Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan, 611130 (China); Sichuan Tourism College, Chengdu, 610000, Sichuan (China); He, Xiujing [Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan, 611130 (China); Gao, Jian [Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University, Key Laboratory of Tumor Immunopathology, Ministry of Education of China, Chongqing (China); Ma, Haixia; Zhang, Zhiming; Shen, Yaou [Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan, 611130 (China); Pan, Guangtang, E-mail: pangt@sicau.edu.cn [Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan, 611130 (China); Lin, Haijian, E-mail: linhj521@gmail.com [Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan, 611130 (China)

    2015-09-04

    The heavy metal cadmium (Cd), acts as a widespread environmental contaminant, which has shown to adversely affect human health, food safety and ecosystem safety in recent years. However, research on how plant respond to various kinds of heavy metal stress is scarcely reported, especially for understanding of complex molecular regulatory mechanisms and elucidating the gene networks of plant respond to Cd stress. Here, transcriptomic changes during Mo17 and B73 seedlings development responsive to Cd pollution were investigated and comparative RNAseq-based approach in both genotypes were performed. 115 differential expression genes (DEGs) with significant alteration in expression were found co-modulated in both genotypes during the maize seedling development; of those, most of DGEs were found comprised of stress and defense responses proteins, transporters, as well as transcription factors, such as thaumatin-like protein, ZmOPR2 and ZmOPR5. More interestingly, genotype-specific transcriptional factors changes induced by Cd stress were found contributed to the regulatory mechanism of Cd sensitivity in both different genotypes. Moreover, 12 co-expression modules associated with specific biological processes or pathways (M1 to M12) were identified by consensus co-expression network. These results will expand our understanding of complex molecular mechanism of response and defense to Cd exposure in maize seedling roots. - Highlights: • Transcriptomic changes responsive to Cd pollution using comparative RNAseq-based approach. • 115 differential expression genes (DEGs) were found co-modulated in both genotypes. • Most of DGEs belong to stress and defense responses proteins, transporters, transcription factors. • 12 co-expression modules associated with specific biological processes or pathways. • Genotype-specific transcriptional factors changes induced by Cd stress were found.

  6. Feline immunodeficiency virus and retrovirus-mediated adventitial ex vivo gene transfer to rabbit carotid artery using autologous vascular smooth muscle cells.

    Science.gov (United States)

    Kankkonen, Hanna M; Turunen, Mikko P; Hiltunen, Mikko O; Lehtolainen, Pauliina; Koponen, Jonna; Leppänen, Pia; Turunen, Anna-Mari; Ylä-Herttuala, Seppo

    2004-03-01

    We have developed an ex vivo gene transfer technique to rabbit arterial wall using autologous smooth muscle cells (SMCs). SMCs were harvested from rabbit ear artery, transduced in vitro with vesicular stomatitis virus G-glycoprotein pseudotyped retrovirus or feline immunodeficiency virus (FIV) and returned to the adventitial surface of the carotid artery using a periadventitial silicone collar or collagen sheet placed around the artery. Beta-galactosidase (lacZ) and human apolipoprotein E3 (apoE3) cDNAs were used as transgenes. After retrovirus-mediated gene transfer of lacZ the selected cells implanted with high efficiency and expressed lacZ marker gene at a very high level 7 and 14 days after the operation. The level of lacZ expression decreased thereafter but was still detectable 12 weeks after the gene transfer, and was exclusively localized to the site of cell implantation inside the collar. Utilizing FIV vector expressing apoE3, low levels of apoE were measured from serum collected from a low-density lipoprotein receptor deficient Watanabe heritable hyperlipidemic rabbits 1 month after the gene transfer. The physiological effect of apoE expression was detected as transiently elevated serum cholesterol levels. The results indicate that the model can be used for high efficiency local gene transfer in arteries, e.g. during vascular surgery. The model is also valuable for studying expression, stability and safety of new gene transfer vectors and their expression products in vivo.

  7. Epigenetic control of root and nodule development : the role of plant-specific histone deacetylases and LHP1 in root cell reprogramming

    NARCIS (Netherlands)

    Schilderink, S.

    2012-01-01

    In plants, unlike in animals, most organs develop post embryonically. These organs originate from clusters of undifferentiated dividing cells that form so-called meristems. Differentiated cells can be re-activated to enter the cell cycle and to ultimately give rise to new meristems. These differenti

  8. The significance of ecology in the development of Verticillium chlamydosporium as a biological agent against root-knot nematodes (Meloidogyne spp.).

    OpenAIRE

    Leij, van der, T.

    1992-01-01

    A thorough understanding of the interactions which occur between nematode parasites and nematode pests and the influence of biotic and abiotic factors on these interactions, is essential in the development of biological control agents for nematodes. The aim of this study was to develop a particular isolate of the nematophagous fungus Verticillium chlamydosporium as a biological control agent for root-knot nematodes. The work has gained insight into some of the key factors which govern the eff...

  9. Micropropagation of Codiaeum variegatum (L.) Blume and regeneration induction via adventitious buds and somatic embryogenesis.

    Science.gov (United States)

    Radice, Silvia

    2010-01-01

    Codiaeum variegatum (L) Blume cv. "Corazon de oro" and cv. "Norma" are successfully micropropagated when culture are initiated with explants taken from newly sprouted shoots. The establishment and multiplication steps are possible when 1 mg/L BA or 1 mg/L IAA and 3 mg/L 2iP are added to MS medium, according to the cultivar respectively selected.Adventive organogenesis and somatic embryogenesis are induced from leaf explants taken from in vitro buds of croton. On leaf-sectioned of "Corazon de oro" cultured in vitro, 1 mg/L BA stimulates continuous somatic embryos development and induces some shoots too. Replacing BA with 1 mg/L TDZ induces up to 100% bud regeneration in the same explants. On the other hand, leaf-sectioned of C. variegatum cv. Norma does not start somatic embryo differentiation if 1 mg/L TDZ is not added to the MS basal medium. Incipient callus is observed after 30 days of culture, and then, subculture to MS with 1 mg/L BA allows the same process to show on the "Corazon de oro" cultivar. Somatic embryos show growth arrest that is partially overcome by transfer to hormone-free basal medium with activated charcoal. Root induction is possible on basal medium plus 1 mg/L IBA. Plantlets in the greenhouse have variegated leaves true-to-type.

  10. Transcription factor WRKY46 modulates the development of Arabidopsis lateral roots in osmotic/salt stress conditions via regulation of ABA signaling and auxin homeostasis.

    Science.gov (United States)

    Ding, Zhong Jie; Yan, Jing Ying; Li, Chun Xiao; Li, Gui Xin; Wu, Yun Rong; Zheng, Shao Jian

    2015-10-01

    The development of lateral roots (LR) is known to be severely inhibited by salt or osmotic stress. However, the molecular mechanisms underlying LR development in osmotic/salt stress conditions are poorly understood. Here we show that the gene encoding the WRKY transcription factor WRKY46 (WRKY46) is expressed throughout lateral root primordia (LRP) during early LR development and that expression is subsequently restricted to the stele of the mature LR. In osmotic/salt stress conditions, lack of WRKY46 (in loss-of-function wrky46 mutants) significantly reduces, while overexpression of WRKY46 enhances, LR development. We also show that exogenous auxin largely restores LR development in wrky46 mutants, and that the auxin transport inhibitor 2,3,5-triiodobenzoic acid (TIBA) inhibits LR development in both wild-type (WT; Col-0) and in a line overexpressing WRKY46 (OV46). Subsequent analysis of abscisic acid (ABA)-related mutants indicated that WRKY46 expression is down-regulated by ABA signaling, and up-regulated by an ABA-independent signal induced by osmotic/salt stress. Next, we show that expression of the DR5:GUS auxin response reporter is reduced in roots of wrky46 mutants, and that both wrky46 mutants and OV46 display altered root levels of free indole-3-acetic acid (IAA) and IAA conjugates. Subsequent RT-qPCR and ChIP-qPCR experiments indicated that WRKY46 directly regulates the expression of ABI4 and of genes regulating auxin conjugation. Finally, analysis of wrky46 abi4 double mutant plants confirms that ABI4 acts downstream of WRKY46. In summary, our results demonstrate that WRKY46 contributes to the feedforward inhibition of osmotic/salt stress-dependent LR inhibition via regulation of ABA signaling and auxin homeostasis.

  11. Infection of Cultured Thin Cell Layer Roots of Lycopersicon esculentum by Meloidogyne incognita.

    Science.gov (United States)

    Radin, D N; Eisenback, J D

    1991-10-01

    A new aseptic culture system for studying interactions between tomato (Lycopersicon esculentum) and Meloidogyne incognita is described. Epidermal thin cell layer explants from peduncles of tomato produced up to 20 adventitious roots per culture in 4-9 days on Murashige &Scoog medium plus kinetin and indole acetic acid. Rooted cultures were transferred to Gamborg's B-5 medium and inoculated with infective second-stage juveniles. Gall formation was apparent 5 days after inoculation and egg production by mature females occurred within 25 days at 25 C in the susceptible genotypes Rutgers and Red Alert. Resistant genotypes LA655, LA656, and LA1022 exhibited a characteristic hypersensitive response. This system provides large numbers of cultured root tips for studies on the molecular basis of the host-parasite relationship.

  12. Anatomy and Histochemistry of Roots and Shoots in Wild Rice (Zizania latifolia Griseb.

    Directory of Open Access Journals (Sweden)

    Chaodong Yang

    2014-01-01

    Full Text Available Wild rice (Zizania latifolia Griseb. is a famous, perennial, emergent vegetable in China. The current work explores the anatomy and histochemistry of roots, stems, and leaves and the permeability of apoplastic barriers of wild rice. The adventitious roots in wild rice have suberized and lignified endodermis and adjacent, thick-walled cortical layers and suberized and lignified hypodermis, composed of a uniseriate sclerenchyma layer (SC underlying uniseriate exodermis; they also have lysigenous aerenchyma. Stems have a thickened epidermal cuticle, a narrow peripheral mechanical ring (PMR, an outer ring of vascular bundles, and an inner ring of vascular bundles embedded in a multiseriate sclerenchyma ring (SCR. There is evidence of suberin in stem SCR and PMR sclerenchyma cells. Sheathing leaves are characterized by thick cuticles and fibrous bundle sheath extensions. Air spaces in stems and leaves consist of mostly lysigenous aerenchyma and pith cavities in stems. Apoplastic barriers are found in roots and stems.

  13. Chronic adventitial inflammation, vasa vasorum expansion, and 5-lipoxygenase up-regulation in irradiated arteries from cancer survivors

    Science.gov (United States)

    Halle, Martin; Christersdottir, Tinna; Bäck, Magnus

    2016-01-01

    Radiation-induced cardiovascular disease is an emerging problem in a steadily increasing population of survivors of cancer. However, the underlying biology is poorly described, and the late onset, which occurs several years after exposure, precludes adequate investigations in animal and cell culture models. We investigated the role of the 5-lipoxygenase (5-LO)/leukotriene pathway in radiation-induced vascular changes. Use of paired samples of irradiated arteries and nonirradiated internal control arteries from the same patient that were harvested during surgery for cancer reconstruction ≤10 yr after radiotherapy provides a unique human model of chronic radiation–induced vascular changes. Immunohistochemical stainings and perioperative inspection revealed an adventitial inflammatory response, with vasa vasorum expansion and chronic infiltration of CD68+ macrophages. These macrophages stained positive for the leukotriene-forming enzyme 5-LO. Messenger RNA levels of 5-LO and leukotriene B4 receptor 1 were increased in irradiated arterial segments compared with control vessels. These results point to targeting the 5-LO/leukotriene pathway as a therapeutic adjunct to prevent late adverse vascular effects of radiotherapy.—Halle, M., Christersdottir, T., Bäck, M. Chronic adventitial inflammation, vasa vasorum expansion, and 5-lipoxygenase up-regulation in irradiated arteries from cancer survivors. PMID:27530979

  14. The beet cyst nematode Heterodera schachtii modulates the expression of WRKY transcription factors in syncytia to favour its development in Arabidopsis roots.

    Science.gov (United States)

    Ali, Muhammad Amjad; Wieczorek, Krzysztof; Kreil, David P; Bohlmann, Holger

    2014-01-01

    Cyst nematodes invade the roots of their host plants as second stage juveniles and induce a syncytium which is the only source of nutrients throughout their life. A recent transcriptome analysis of syncytia induced by the beet cyst nematode Heterodera schachtii in Arabidopsis roots has shown that thousands of genes are up-regulated or down-regulated in syncytia as compared to root segments from uninfected plants. Among the down-regulated genes are many which code for WRKY transcription factors. Arabidopsis contains 66 WRKY genes with 59 represented by the ATH1 GeneChip. Of these, 28 were significantly down-regulated and 6 up-regulated in syncytia as compared to control root segments. We have studied here the down-regulated genes WRKY6, WRKY11, WRKY17 and WRKY33 in detail. We confirmed the down-regulation in syncytia with promoter::GUS lines. Using various overexpression lines and mutants it was shown that the down-regulation of these WRKY genes is important for nematode development, probably through interfering with plant defense reactions. In case of WRKY33, this might involve the production of the phytoalexin camalexin.

  15. The beet cyst nematode Heterodera schachtii modulates the expression of WRKY transcription factors in syncytia to favour its development in Arabidopsis roots.

    Directory of Open Access Journals (Sweden)

    Muhammad Amjad Ali

    Full Text Available Cyst nematodes invade the roots of their host plants as second stage juveniles and induce a syncytium which is the only source of nutrients throughout their life. A recent transcriptome analysis of syncytia induced by the beet cyst nematode Heterodera schachtii in Arabidopsis roots has shown that thousands of genes are up-regulated or down-regulated in syncytia as compared to root segments from uninfected plants. Among the down-regulated genes are many which code for WRKY transcription factors. Arabidopsis contains 66 WRKY genes with 59 represented by the ATH1 GeneChip. Of these, 28 were significantly down-regulated and 6 up-regulated in syncytia as compared to control root segments. We have studied here the down-regulated genes WRKY6, WRKY11, WRKY17 and WRKY33 in detail. We confirmed the down-regulation in syncytia with promoter::GUS lines. Using various overexpression lines and mutants it was shown that the down-regulation of these WRKY genes is important for nematode development, probably through interfering with plant defense reactions. In case of WRKY33, this might involve the production of the phytoalexin camalexin.

  16. ROBAST: Development of a ROOT-based ray-tracing library for cosmic-ray telescopes and its applications in the Cherenkov Telescope Array

    Science.gov (United States)

    Okumura, Akira; Noda, Koji; Rulten, Cameron

    2016-03-01

    We have developed a non-sequential ray-tracing simulation library, ROOT-basedsimulatorforraytracing (ROBAST), which is aimed to be widely used in optical simulations of cosmic-ray (CR) and gamma-ray telescopes. The library is written in C++, and fully utilizes the geometry library of the ROOT framework. Despite the importance of optics simulations in CR experiments, no open-source software for ray-tracing simulations that can be widely used in the community has existed. To reduce the dispensable effort needed to develop multiple ray-tracing simulators by different research groups, we have successfully used ROBAST for many years to perform optics simulations for the Cherenkov Telescope Array (CTA). Among the six proposed telescope designs for CTA, ROBAST is currently used for three telescopes: a Schwarzschild-Couder (SC) medium-sized telescope, one of SC small-sized telescopes, and a large-sized telescope (LST). ROBAST is also used for the simulation and development of hexagonal light concentrators proposed for the LST focal plane. Making full use of the ROOT geometry library with additional ROBAST classes, we are able to build the complex optics geometries typically used in CR experiments and ground-based gamma-ray telescopes. We introduce ROBAST and its features developed for CR experiments, and show several successful applications for CTA.

  17. Development of Chromatographic Fingerprints of Eurycoma longifolia (Tongkat Ali) Roots Using Online Solid Phase Extraction-Liquid Chromatography (SPE-LC).

    Science.gov (United States)

    Zaini, Nor Nasriah; Osman, Rozita; Juahir, Hafizan; Saim, Norashikin

    2016-04-30

    E. longifolia is attracting interest due to its pharmacological properties and pro-vitality effects. In this study, an online SPE-LC approach using polystyrene divinyl benzene (PSDVB) and C18 columns was developed in obtaining chromatographic fingerprints of E. longifolia. E. longifolia root samples were extracted using pressurized liquid extraction (PLE) technique prior to online SPE-LC. The effects of mobile phase compositions and column switching time on the chromatographic fingerprint were optimized. Validation of the developed method was studied based on eurycomanone. Linearity was in the range of 5 to 50 µg∙mL(-1) (r² = 0.997) with 3.2% relative standard deviation of peak area. The developed method was used to analyze 14 E. longifolia root samples and 10 products (capsules). Selected chemometric techniques: cluster analysis (CA), discriminant analysis (DA), and principal component analysis (PCA) were applied to the fingerprint datasets of 37 selected peaks to evaluate the ability of the chromatographic fingerprint in classifying quality of E. longifolia. Three groups were obtained using CA. DA yielded 100% correlation coefficient with 19 discriminant compounds. Using PCA, E. longifolia root samples were clearly discriminated from the products. This study showed that the developed online SPE-LC method was able to provide comprehensive evaluation of E. longifolia samples for quality control purposes.

  18. Expression of nodule-specific genes in alfalfa root nodules blocked at an early stage of development.

    NARCIS (Netherlands)

    Dickstein, R.; Bisseling, T.; Reinhold, V.N.; Ausubel, F.M.

    1988-01-01

    To help dissect the molecular basis of the Rhizobium-legume symbiosis, we used in vitro translation and Northern blot analysis of nodule RNA to examine alfalfa-specific genes (nodulins) expressed in two types of developmentally defective root nodules elicited by Rhizobium meliloti. Fix- nodules were

  19. Root Hair Development in the Grasses: What We Already Know and What We Still Need to Know1

    Science.gov (United States)

    Melzer, Michael

    2015-01-01

    A priority in many crop improvement programs for a long time has been to enhance the tolerance level of plants to both abiotic and biotic stress. Recognition that the root system is the prime determinant of a plant’s ability to extract both water and minerals from the soil implies that its architecture is an important variable underlying a cultivar’s adaptation. The density and/or length of the root hairs (RHs) that are formed are thought to have a major bearing on the plant’s performance under stressful conditions. Any attempt to improve a crop’s root system will require a detailed understanding of the processes of RH differentiation. Recent progress in uncovering the molecular basis of root epidermis specialization has been recorded in the grasses. This review seeks to present the current view of RH differentiation in grass species. It combines what has been learned from molecular-based analyses, histological studies, and observation of the phenotypes of both laboratory- and field-grown plants. PMID:25873551

  20. 根发育过程中生长素、多胺和NO的关系%Relationships of Auxin, Polyamine and NO during Roots Development

    Institute of Scientific and Technical Information of China (English)

    张媛华; 张韶杰

    2012-01-01

    The relationships of auxin, polyamine and nitric oxide (NO) with root development were summarized, and the production mecha nisms of NO induced by auxin and polyamine was discussed.%综述了生长素、多胺和一氧化氮(NO)与根发育的关系,讨论了生长素和多胺诱导NO产生的机制.

  1. Interactive effects of soil temperature, atmospheric carbon dioxide and soil N on root development, biomass and nutrient uptake of winter wheat during vegetative growth.

    Science.gov (United States)

    Gavito, M E; Curtis, P S; Mikkelsen, T N; Jakobsen, I

    2001-09-01

    Nutrient requirements for plant growth are expected to rise in response to the predicted changes in CO(2) and temperature. In this context, little attention has been paid to the effects of soil temperature, which limits plant growth at early stages in temperate regions. A factorial growth-room experiment was conducted with winter wheat, varying soil temperature (10 degrees C and 15 degrees C), atmospheric CO(2) concentration (360 and 700 ppm), and N supply (low and high). The hypothesis was that soil temperature would modify root development, biomass allocation and nutrient uptake during vegetative growth and that its effects would interact with atmospheric CO(2) and N availability. Soil temperature effects were confirmed for most of the variables measured and 3-factor interactions were observed for root development, plant biomass components, N-use efficiency, and shoot P content. Importantly, the soil temperature effects were manifest in the absence of any change in air temperature. Changes in root development, nutrient uptake and nutrient-use efficiencies were interpreted as counterbalancing mechanisms for meeting nutrient requirements for plant growth in each situation. Most variables responded to an increase in resource availability in the order: N supply >soil temperature >CO(2).

  2. Development of upland rice introgression lines and identification of QTLs for basal root thickness under different water regimes

    Institute of Scientific and Technical Information of China (English)

    Junzhou Li; Deping Wang; Yan Xie a; Hongliang Zhang; Guanglong Hu; Jinjie Li; Anyong Dai; Lifeng Liu; Zichao Li

    2011-01-01

    Introgression lines (ILs) are valuable materials for identifying quantitative trait loci (QTLs),evaluating genetic interactions,and marker assisted breeding.A set of 430 ILs (BC5F3) containing segments from upland tropical japonica cultivar IRAT109 in a lowland temperate japonica cultivar Yuefu background were developed.One hundred and seventy-six polymorphic markers were used to identify introgressed segments.No segment from IRAT 109 was found in 160 lines.Introgressed segments of the other 270 lines covered 99.1% of the donor genome.The mean number of introgressed donor segments per individual was 3.3 with an average length of 14.4 cM.QTL analysis was conducted on basal root thickness (BRT) of the 270 ILs grown under irrigated lowland,upland and hydroponic conditions.A total of 22 QTLs affecting BRT were identified,six QTLs (qBRT3.1,qBRT3.2,qBRT6.1,qBRT8.2,qBRT9.1,and qBRT9.2) were consistently expressed under at least two environments (location and water regime),and qBRT7.2 was a new BRT QTL identified under lowland conditions.IL255 containing qBRT9.1 showed an increase of 10.09% and 7.07% BRT over cultivar Yuefu when grown under upland and lowland conditions,respectively.Using a population of 304 F2:3 lines derived from the cross IL255 × Yuefu,qBRT9.1 was validated and mapped to a 1.2 cM interval between RM24271 and RM566.The presence of qBRT9.1 explained 12% of BRT variation.The results provide upland rice ILs and BRT QTLs for analyzing the genetic basis of drought resistance,detecting favorable genes from upland rice,and rice drought resistance breeding.

  3. Production Performance of Root Systems of Four Forage Legume Species and Their Development Characteristics in Loess Plateau,China

    Institute of Scientific and Technical Information of China (English)

    Zhang; Jianquan; Zhang; Jiyu; Wang; Yanrong; Xie; Wengang; Li; Juncheng

    2014-01-01

    Production performance of four forage legumes species of Medicago sativa,Onobrychis viciifolia,Lotus corniculatus and Galega officinalis were determined,including plant height,above-ground biomass per unit area,tillers per unit area,fertile tillers per unit area,shoot /leaf ratio and fresh /dry matter weight ratio,and the distribution characteristics of their root systems in 0- 100 cm soil layers with 10 cm interval were studied. Results showed that the average aboveground fresh biomass(4 a and 5 a) of four forage legumes species successively were L. corniculatus > M. sativa > O. viciifolia > G. officinalis. The average plant heights in two years successively were O. viciifolia > M. sativa > G. officinalis > L. corniculatus. Tillers per unit area of four forage legume species in two years successively were M. sativa > L. corniculatus > O. viciifolia > G. officinalis. Fertile tillers per unit area in two years were O. viciifolia > M. sativa > L. corniculatus > G. officinalis. Average shoot /leaf ratio in two years were G. officinalis > M. sativa > O. viciifolia > L. corniculatus. Average moisture contents of four forage legume species in two years successively were G. officinalis > L. corniculatus > M. sativa = O. viciifolia. The distribution characteristics of root systems of four forage legumes species in 0- 100 cm soil layers were as follows: the root weights of M. sativa in 0- 40 cm soil layers accounted for about 98. 3% of total root weight,that of O. viciifolia in 0- 30 cm soil layers was 85. 8%,that of L. corniculatus in 0- 10 cm soil layers was 80%,and that of G. officinalis in 0- 40 cm soil layers was 81. 4%. The results suggested that L. corniculatus was suited to plant in slighter degraded pasture to control water and soil erosion in early stage,G. officinalis with strong lateral roots was adapted to degraded grassland in the Loess Plateau where soil nutrient was poor,while O. viciifolia and M. sativa with potentially strong main root were fit for water

  4. Isoschaftoside, a C-glycosylflavonoid from Desmodium uncinatum root exudate, is an allelochemical against the development of Striga.

    Science.gov (United States)

    Hooper, Antony M; Tsanuo, Muniru K; Chamberlain, Keith; Tittcomb, Kay; Scholes, Julie; Hassanali, Ahmed; Khan, Zeyaur R; Pickett, John A

    2010-06-01

    In East African small-holder farming of maize, the cattle forage legume, Desmodium uncinatum is used as an intercrop due to its allelopathic inhibition of parasitism by Striga hermonthica, an obligate parasitic weed that can devastate the maize crop. Bioassay-guided fractionation of the root extract of D. uncinatum revealed isoschaftoside to be the main compound in the most potent fraction inhibiting growth of germinated S. hermonthica radicles. Bioassays repeated with isoschaftoside isolated from a different plant source, Passiflora incarnata, proved it to be a biologically active component. Analysis of the root exudates produced by hydroponically grown D. uncinatum showed isoschaftoside to be present in the hydroponic media at biologically active concentrations of 10-100 nM.

  5. Involvement of the plant antioxidative response in the differential growth sensitivity to salinity of leaves vs roots during cell development.

    Science.gov (United States)

    Bernstein, Nirit; Shoresh, Michal; Xu, Yan; Huang, Bingru

    2010-10-15

    Sensitivity to salinity varies between plant organs and between cells of different developmental stages within a single organ. The physiological and molecular bases for the differential responses are not known. Exposure of plants to salinity is known to induce formation of reactive oxygen species (ROS), which are involved in damage mechanisms but also in cell growth processes. The objective of this study was to elucidate developmental-stage-specific and organ-specific involvement of oxidative defense in the plant response to salinity in maize (Zea mays L.). Plants were grown in nutrient solution containing 1mM NaCl (control) or 80mM NaCl. The oxidative stress response and damage symptoms along the cell developmental gradient in growing and mature tissue of leaves and roots were examined. Unlike leaves, roots did not suffer oxidative damage in either growing or mature cells and demonstrated reduced antioxidant response. This may reflect different requirements of ROS for growth mechanisms of leaf and root cells. In leaves, growing tissue demonstrated higher stimulation of superoxide dismutase (SOD) and ascorbate peroxidase (APX) activity under salinity than mature tissue, whereas mature tissue demonstrated higher stimulation of catalase. These results indicate differential roles for these ROS-scavenging enzymes at different cell developmental stages. Because ROS are required for cell expansion, the higher increase in SOD and APX activities in the growing leaf cells that resulted in reduction of ROS content under salinity could lead to the inhibition of cell growth under salinity.

  6. Development and Identification of SSR Markers Associated with Starch Properties and β-Carotene Content in the Storage Root of Sweet Potato (Ipomoea batatas L.)

    Science.gov (United States)

    Zhang, Kai; Wu, Zhengdan; Tang, Daobin; Lv, Changwen; Luo, Kai; Zhao, Yong; Liu, Xun; Huang, Yuanxin; Wang, Jichun

    2016-01-01

    Sweet potato (Ipomoea batatas L.) is a nutritious food crop and, based on the high starch content of its storage root, a potential bioethanol feedstock. Enhancing the nutritional value and starch quantity of storage roots are important goals of sweet potato breeding programs aimed at developing improved varieties for direct consumption, processing, and industrial uses. However, developing improved lines of sweet potato is challenging due to the genetic complexity of this plant and the lack of genome information. Short sequence repeat (SSR) markers are powerful molecular tools for tracking important loci in crops and for molecular-based breeding strategies; however, few SSR markers and marker-trait associations have hitherto been identified in sweet potato. In this study, we identified 1824 SSRs by using a de novo assembly of publicly available ESTs and mRNAs in sweet potato, and designed 1476 primer pairs based on SSR-containing sequences. We mapped 214 pairs of primers in a natural population comprised of 239 germplasms, and identified 1278 alleles with an average of 5.972 alleles per locus and a major allele frequency of 0.7702. Population structure analysis revealed two subpopulations in this panel of germplasms, and phenotypic characterization demonstrated that this panel is suitable for association mapping of starch-related traits. We identified 32, 16, and 17 SSR markers associated with starch content, β-carotene content, and starch composition in the storage root, respectively, using association analysis and further evaluation of a subset of sweet potato genotypes with various characteristics. The SSR markers identified here can be used to select varieties with desired traits and to investigate the genetic mechanism underlying starch and carotenoid formation in the starchy roots of sweet potato. PMID:26973669

  7. Using coloured roots to study root interaction and competition in intercropped legumes and non-legumes

    DEFF Research Database (Denmark)

    Tosti, Giacomo; Thorup-Kristensen, Kristian

    2010-01-01

    if a species with coloured roots can be used to examine the interaction in a legume-non-legume intercropping system; (ii) to verify the importance of initial root growth on the successive root development of mixture component plants; (iii) to test if the root interaction in the shallow layers has consequences...

  8. Determinants and Polynomial Root Structure

    Science.gov (United States)

    De Pillis, L. G.

    2005-01-01

    A little known property of determinants is developed in a manner accessible to beginning undergraduates in linear algebra. Using the language of matrix theory, a classical result by Sylvester that describes when two polynomials have a common root is recaptured. Among results concerning the structure of polynomial roots, polynomials with pairs of…

  9. Project Work on Plant Roots.

    Science.gov (United States)

    Devonald, V. G.

    1986-01-01

    Methods of investigating plant root growth developed for research purposes can be adopted for student use. Investigations of the effect of water table level and of ethylene concentration are described, and techniques of measuring root growth are explained. (Author/ML)

  10. Incorporation of a Reporter Peptide in FPOP Compensates for Adventitious Scavengers and Permits Time-Dependent Measurements

    Science.gov (United States)

    Niu, Ben; Mackness, Brian C.; Rempel, Don. L.; Zhang, Hao; Cui, Weidong; Matthews, C. Robert; Zitzewitz, Jill A.; Gross, Michael L.

    2017-02-01

    Incorporation of a reporter peptide in solutions submitted to fast photochemical oxidation of proteins (FPOP) allows for the correction of adventitious scavengers and enables the normalization and comparison of time-dependent results. Reporters will also be useful in differential experiments to control for the inclusion of a radical-reactive species. This incorporation provides a simple and quick check of radical dosage and allows comparison of FPOP results from day-to-day and lab-to-lab. Use of a reporter peptide in the FPOP workflow requires no additional measurements or spectrometers while building a more quantitative FPOP platform. It requires only measurement of the extent of reporter-peptide modification in a LC/MS/MS run, which is performed by using either data-dependent scanning or an inclusion list.

  11. Adventitious presence of other varieties in oilseed rape (¤Brassica napus¤) from seed banks and certified seed

    DEFF Research Database (Denmark)

    Jørgensen, T.; Hauser, Thure Pavlo; Bagger Jørgensen, Rikke

    2007-01-01

    To obtain information on possible sources of contamination of the seed harvest of oilseed rape (Brassica napus L., spp. napus) by other varieties (adventitious presence), we investigated the purity of certified seed lots; the abundance and origin of volunteers; and longevity and origin of seeds...... in the soil seed-bank. This information was acquired through DNA analysis of volunteers collected in the field and seedlings derived from the soil seed-bank. DNA profiles of the volunteers and seedlings were obtained using Inter Simple Sequence Repeat (ISSR) markers, and the profiles were compared with ISSR...... profiles from an assortment of 14 of the most commonly cultivated oilseed rape varieties from 1985 to 2004. This comparison was performed using the assignment program, AFLPOP. The age of the seed bank germinating to become volunteers was assumed from information on previously cultivated oilseed rape...

  12. Incorporation of a Reporter Peptide in FPOP Compensates for Adventitious Scavengers and Permits Time-Dependent Measurements

    Science.gov (United States)

    Niu, Ben; Mackness, Brian C.; Rempel, Don. L.; Zhang, Hao; Cui, Weidong; Matthews, C. Robert; Zitzewitz, Jill A.; Gross, Michael L.

    2016-12-01

    Incorporation of a reporter peptide in solutions submitted to fast photochemical oxidation of proteins (FPOP) allows for the correction of adventitious scavengers and enables the normalization and comparison of time-dependent results. Reporters will also be useful in differential experiments to control for the inclusion of a radical-reactive species. This incorporation provides a simple and quick check of radical dosage and allows comparison of FPOP results from day-to-day and lab-to-lab. Use of a reporter peptide in the FPOP workflow requires no additional measurements or spectrometers while building a more quantitative FPOP platform. It requires only measurement of the extent of reporter-peptide modification in a LC/MS/MS run, which is performed by using either data-dependent scanning or an inclusion list.

  13. Nuevas citas de monocotiledóneas adventicias para la Argentina New records of adventitious monocots for Argentina

    Directory of Open Access Journals (Sweden)

    Julio A. Hurrell

    2009-12-01

    Full Text Available Este trabajo incluye cinco nuevos registros de monocotiledóneas adventicias para la Argentina: Aloe ciliaris Haw. (Asphodelaceae, Aspidistra elatior Blume (Convallariaceae, Sansevieria trifasciata Prain (Dracaenaceae, Phormium tenax J. R. Forst. & G. Forst. (Hemerocallidaceae y Ornithogalum arabicum L. (Hyacinthaceae, pertenecientes al orden Asparagales. También incluye una evaluación del estado actual de estas especies, en relación al proceso de naturalización: escapadas de cultivo ocasionales, naturalizadas.This paper includes five new records of adventitious monocots for Argentina: Aloe ciliaris Haw. (Asphodelaceae, Aspidistra elatior Blume (Convallariaceae, Sansevieria trifasciata Prain (Dracaenaceae, Phormium tenax J. R. Forst. & G. Forst. (Hemerocallidaceae and Ornithogalum arabicum L. (Hyacinthaceae, belonging to order Asparagales. Also includes an evaluation of its status in the naturalization process: casual alien, naturalized.

  14. Calogênese e brotações adventícias em tecido somático de Kiwi suplementados com Thidiazuron Callogenesis and adventitious shoots in Kiwi somatic tissue suplemented with Thidiazuron

    Directory of Open Access Journals (Sweden)

    Eva Choer

    1997-08-01

    concentrations of Thidiazuron (8 and 16mg/l were phytotoxic, leading to explant death. Rooting was observed only in the control treatment. Callus intensity formation, adventitious shoots number, callus dry matter weight and bud number showed a quadratic response to the Thidiazuron concentrations. Concentrations of Thidimuron were not efficient to increase the adventitious shoot number of Kiwi. Callus intensity increased until 2.21 mg/l Thidiazuron concentrations, and declined afterwards.

  15. How Do Rare Earth Elements (Lanthanoids Affect Root Development and Protocorm-Like Body Formation in Hybrid CYMBIDIUM?

    Directory of Open Access Journals (Sweden)

    Teixeira da Silva Jaime A.

    2014-09-01

    Full Text Available Only few studies in the plant tissue culture literature have examined the impact of lanthanoids, or rare earth elements, on in vitro plant organogenesis. In this study, using a model plant, hybrid Cymbidium Twilight Moon ‘Day Light’, the impact of six lanthanoids (lanthanum (III nitrate hexahydrate (La(NO33 · 6H2O, cerium (III nitrate hexahydrate (Ce(NO33 · 6H2O, neodymium (III nitrate hexahydrate (Nd(NO33 · 6H2O, praseodymium (III nitrate hexahydrate (Pr(NO33 · 6H2O, samarium (III nitrate hexahydrate (Sm(NO33 · 6H2O, gadolinium (III nitrate hexahydrate (Gd(NO33 · 6H2O on new protocorm-like body (neo-PLB formation on Teixeira Cymbidium (TC medium was examined. 0 (control, 1, 2, 4 and 8 mg·dm-3 of each lanthanoid was tested. All lanthanoids could produce more neo-PLBs and neo-PLB fresh weight than TC medium lacking plant growth regulators (PGRs, suggesting some PGR-like ability of lanthanoids, although PLB-related traits (percentage of half-PLBs forming neo-PLBs; number of neo-PLBs formed per half-PLB; fresh weight of half-PLB + neo-PLBs was always significantly lower than TC medium containing PGRs. Except for Gd, all other lanthanoids had no negative impact on the number of new leaves from neo-PLB-derived shoots, but all lanthanoids showed a significantly lower plant height, shoot fresh weight and shoot dry weight and, in most cases, SPAD (chlorophyll content value. In addition, using the same concentration of the six lanthanoids, the ability to fortify root formation of neo-PLB-derived plantlets was also assessed. Except for Sm, all other lanthanoids significantly increased the number of roots, root fresh and dry weight.

  16. Development and assessment of an efficient numerical solution of the richard's equation including root extraction by plants

    Science.gov (United States)

    Varado, N.; Braud, I.; Ross, P. J.

    2003-04-01

    A new numerical method for solving the 1D Richard's equation has been proposed by P. Ross (Agronomy J., 2003, in press). The Kirchhoff transform or degree of saturation is used instead of the classical matrix potential. The solution can be used both for saturated or non saturated soils. Hydraulic properties are described using the Brooks and Corey model. The soil is discretized into layers. Their thickness can be larger than in classical matrix potential methods, due to the use of a time and space varying weighing procedure for the calculation of fluxes between layers. This allows the use of a non iterative procedure, ensuring a very fast numerical solution. Extensive tests showed that the new method was very accurate for bare soils. The next step was the addition of a root extraction module in order to account for plant transpiration. Two root water uptake modules with compensation mechanisms in case of water stress were chosen from the literature. They express the transpiration source term in the Richards equation as a linear function of a potential transpiration and take into account water stress and its effects on plant transpiration. These modules were proposed first by Lai and Katul (Adv. Water Resour., 2000) and Li et al. (J. Hydrol., 2001). The new version of the model has been tested in a systematic way with several soils characteristics, climate forcings, and evapotranspiration calculation. Like the tests without vegetation, the SiSPAT (Simple Soil Plant Atmosphere Transfer) model was considered as a reference after implementation of the same roots modules. The numerical solution was also tested using a soybean data set. The variations and the cumulative values like drainage, water content, real transpiration and real evapotranspiration were in a good agreement with the SiSPAT modelling, with a relative error of less than 3%. The error on soil evaporation remained important (about 20%) on low cumulative values (less than 20mm), i.e. when LAI was close to

  17. Virus-induced gene silencing (VIGS) as a reverse genetic tool to study development of symbiotic root nodules

    DEFF Research Database (Denmark)

    Kjær, Gabriela Didina Constantin; Grønlund, Mette; Stougaard, Jens

    2008-01-01

    was mediated by agroinfiltration and, 2 weeks later, a Rhizobium leguminosarum bv. viceae culture was added in order to induce root nodulation. At this time point, it was estimated that systemic silencing was established because leaves of reference plants inoculated with PEBV carrying a fragment of Phytoene...... desaturase displayed photo bleaching. Three weeks after Rhizobium spp. application, plants inoculated with a control vector nodulated normally, whereas nodulation was almost eliminated in plants inoculated with a vector carrying PsNinA and PsNinC. For plants inoculated with a vector carrying Ps...

  18. Development of Fe-deficiency responses in cucumber (Cucumis sativus L.) roots: involvement of plasma membrane H(+)-ATPase activity.

    Science.gov (United States)

    Dell'Orto, M; Santi, S; De Nisi, P; Cesco, S; Varanini, Z; Zocchi, G; Pinton, R

    2000-04-01

    One of the mechanisms through which some strategy I plants respond to Fe-deficiency is an enhanced acidification of the rhizosphere due to proton extrusion. It was previously demonstrated that under Fe-deficiency, a strong increase in the H(+)-ATPase activity of plasma membrane (PM) vesicles isolated from cucumber roots occurred. This result was confirmed in the present work and supported by measurement of ATP-dependent proton pumping in inside-out plasma membrane vesicles. There was also an attempt to clarify the regulatory mechanism(s) which lead to the activation of the H(+)-ATPase under Fe-deficiency conditions. Plasma membrane proteins from Fe-deficient roots submitted to immunoblotting using polyclonal antibodies showed an increased level in the 100 kDa polypeptide. When the plasma membrane proteins were treated with trypsin a 90 kDa band appeared. This effect was accompanied by an increase in the enzyme activity, both in the Fe-deficient and in the Fe-sufficient extracts. These results suggest that the increase in the plasma membrane H(+)-ATPase activity seen under Fe-deficiency is due, at least in part, to an increased steady-state level of the 100 kDa polypeptide.

  19. A Glycine soja 14-3-3 protein GsGF14o participates in stomatal and root hair development and drought tolerance in Arabidopsis thaliana.

    Science.gov (United States)

    Sun, Xiaoli; Luo, Xiao; Sun, Mingzhe; Chen, Chao; Ding, Xiaodong; Wang, Xuedong; Yang, Shanshan; Yu, Qingyue; Jia, Bowei; Ji, Wei; Cai, Hua; Zhu, Yanming

    2014-01-01

    It is well established that 14-3-3 proteins are key regulators of multiple stress signal transduction cascades. However, the biological functions of soybean 14-3-3 proteins, especially in plant drought response, are not yet known. In this study, we characterized a Glycine soja 14-3-3 gene, GsGF14o, which is involved in plant development and drought response. GsGF14o expression was greatly induced by drought stress, as evidenced by the quantitative real-time PCR and β-glucuronidase (GUS) activity analysis. GsGF14o overexpression in Arabidopsis thaliana resulted in decreased drought tolerance during seed germination and seedling growth. Furthermore, silencing of AtGF14µ, the most homologous 14-3-3 gene of GsGF14o, led to enhanced drought tolerance at both the seed germination and seedling stage. Unexpectedly, GsGF14o transgenic lines showed reduced water loss and transpiration rates compared with wild-type plants, which was demonstrated to be the consequence of the decreased stomatal size. At the same time, the smaller stomata due to GsGF14o overexpression led to a relatively slow net photosynthesis rate, which led to a growth penalty under drought stress. We further demonstrated that GsGF14o overexpression caused deficits in root hair formation and development, and thereby reduced the water intake capacity of the transgenic root system. In addition, GsGF14o overexpression down-regulated the transcript levels of drought-responsive marker genes. Finally, we also investigated the tissue-specific accumulation of GsGF14o by using a GUS activity assay. Collectively, the results presented here confirm that GsGF14o plays a dual role in drought stress responses through its involvement in the regulation of stomatal size and root hair development.

  20. Development of Roots Blower with High Temperature%高温罗茨鼓风机的研发

    Institute of Scientific and Technical Information of China (English)

    张海芹

    2013-01-01

      介绍了一种进气温度高达200℃的高温用途罗茨鼓风机,并着重阐述了机组的隔热结构设计、高温气体密封、降温设计和选用的隔热材料。通过对机组进行200℃高温性能试验,验证了机组性能满足工况要求。%This paper introduced a type of roots blower with inlet temperature up to 200℃ for high temperature application. And this paper focused on heat insulation design, high-temperature gas seal, cooling design and selection of heat insulation material of the unit. The unit performance meeting the operating requirement was verified based on the 200℃ high temperature performance test for the unit.

  1. Basic Pentacysteine Proteins Repress Abscisic Acid Insensitive4 Expression via Direct Recruitment of the Polycomb-Repressive Complex 2 in Arabidopsis Root Development.

    Science.gov (United States)

    Mu, Ying; Zou, Meijuan; Sun, Xuwu; He, Baoye; Xu, Xiumei; Liu, Yini; Zhang, Lixin; Chi, Wei

    2017-01-30

    Plant transcription factors generally act in complex regulatory networks that function at multiple levels to govern plant developmental programs. Dissection of the interconnections among different classes of transcription factors can elucidate these regulatory networks and thus improve our understanding of plant development. Here, we investigated the molecular and functional relationships of the transcription factors ABSCISIC ACID INSENSITIVE 4 (ABI4) and members of the BASIC PENTACYSTEINE (BPC) family in lateral root (LR) development of Arabidopsis thaliana Genetic analysis showed that BPCs promote LR development by repressing ABI4 expression. Molecular analysis showed that BPCs bind to the ABI4 promoter and repress ABI4 transcription in roots. BPCs directly recruit the Polycomb Repressive Complex 2 (PRC2) to the ABI4 locus and epigenetically repress ABI4 expression by catalyzing the trimethylation of histone H3 at lysine 27. In addition, BPCs and ABI4 coordinate their activities to fine-tune the levels of PIN-FORMED1, a component of the auxin signaling pathway, and thus modulate LR formation. These results establish a functional relationship between two universal and multiple-role transcription factors and provide insight into the mechanisms of the transcriptional regulatory networks that affect Arabidopsis organogenesis.

  2. crinkle, a novel symbiotic mutant that affects the infection thread growth and alters the root hair, trichome, and seed development in Lotus japonicus.

    Science.gov (United States)

    Tansengco, Myra L; Hayashi, Makoto; Kawaguchi, Masayoshi; Imaizumi-Anraku, Haruko; Murooka, Yoshikatsu

    2003-03-01

    To elucidate the mechanisms involved in Rhizobium-legume symbiosis, we examined a novel symbiotic mutant, crinkle (Ljsym79), from the model legume Lotus japonicus. On nitrogen-starved medium, crinkle mutants inoculated with the symbiont bacterium Mesorhizobium loti MAFF 303099 showed severe nitrogen deficiency symptoms. This mutant was characterized by the production of many bumps and small, white, uninfected nodule-like structures. Few nodules were pale-pink and irregularly shaped with nitrogen-fixing bacteroids and expressing leghemoglobin mRNA. Morphological analysis of infected roots showed that nodulation in crinkle mutants is blocked at the stage of the infection process. Confocal microscopy and histological examination of crinkle nodules revealed that infection threads were arrested upon penetrating the epidermal cells. Starch accumulation in uninfected cells and undeveloped vascular bundles were also noted in crinkle nodules. Results suggest that the Crinkle gene controls the infection process that is crucial during the early stage of nodule organogenesis. Aside from the symbiotic phenotypes, crinkle mutants also developed morphological alterations, such as crinkly or wavy trichomes, short seedpods with aborted embryos, and swollen root hairs. crinkle is therefore required for symbiotic nodule development and for other aspects of plant development.

  3. ROBAST: Development of a ROOT-Based Ray-Tracing Library for Cosmic-Ray Telescopes and its Applications in the Cherenkov Telescope Array

    CERN Document Server

    Okumura, Akira; Rulten, Cameron

    2016-01-01

    We have developed a non-sequential ray-tracing simulation library, ROOT-based simulator for ray tracing (ROBAST), which is aimed to be widely used in optical simulations of cosmic-ray (CR) and gamma-ray telescopes. The library is written in C++, and fully utilizes the geometry library of the ROOT framework. Despite the importance of optics simulations in CR experiments, no open-source software for ray-tracing simulations that can be widely used in the community has existed. To reduce the dispensable effort needed to develop multiple ray-tracing simulators by different research groups, we have successfully used ROBAST for many years to perform optics simulations for the Cherenkov Telescope Array (CTA). Among the six proposed telescope designs for CTA, ROBAST is currently used for three telescopes: a Schwarzschild-Couder (SC) medium-sized telescope, one of SC small-sized telescopes, and a large-sized telescope (LST). ROBAST is also used for the simulation and development of hexagonal light concentrators propose...

  4. Wake development behind paired wings with tip and root trailing vortices: consequences for animal flight force estimates.

    Directory of Open Access Journals (Sweden)

    Jan T Horstmann

    Full Text Available Recent experiments on flapping flight in animals have shown that a variety of unrelated species shed a wake behind left and right wings consisting of both tip and root vortices. Here we present an investigation using Particle Image Velocimetry (PIV of the behaviour and interaction of trailing vortices shed by paired, fixed wings that simplify and mimic the wake of a flying animal with a non-lifting body. We measured flow velocities at five positions downstream of two adjacent NACA 0012 aerofoils and systematically varied aspect ratio, the gap between the wings (corresponding to the width of a non-lifting body, angle of attack, and the Reynolds number. The range of aspect ratios and Reynolds number where chosen to be relevant to natural fliers and swimmers, and insect flight in particular. We show that the wake behind the paired wings deformed as a consequence of the induced flow distribution such that the wingtip vortices convected downwards while the root vortices twist around each other. Vortex interaction and wake deformation became more pronounced further downstream of the wing, so the positioning of PIV measurement planes in experiments on flying animals has an important effect on subsequent force estimates due to rotating induced flow vectors. Wake deformation was most severe behind wings with lower aspect ratios and when the distance between the wings was small, suggesting that animals that match this description constitute high-risk groups in terms of measurement error. Our results, therefore, have significant implications for experimental design where wake measurements are used to estimate forces generated in animal flight. In particular, the downstream distance of the measurement plane should be minimised, notwithstanding the animal welfare constraints when measuring the wake behind flying animals.

  5. The development of a green approach for the biosynthesis of silver and gold nanoparticles by using Panax ginseng root extract, and their biological applications.

    Science.gov (United States)

    Singh, Priyanka; Kim, Yeon Ju; Wang, Chao; Mathiyalagan, Ramya; Yang, Deok Chun

    2016-06-01

    The biosynthesis of nanoparticles has received attention because of the development of economic and environmentally friendly technology for the synthesis of nanoparticles. The study develops a convenient method for the green synthesis of silver and gold nanoparticles by utilizing fresh root extract of the four-year old Panax ginseng plant, and evaluated the antimicrobial applications of silver nanoparticles against pathogenic microorganisms. P. ginseng is a well-known herbal medicinal plant, and its active ingredients are mainly ginsenosides. The fresh root of the 4 year old P. ginseng plant has been explored for the synthesis of silver and gold nanoparticles without the use of any additional reducing and capping agents. The reduction of silver nitrate led to the formation of silver nanoparticles within 2 h of reaction at 80°C. The gold nanoparticles were also successfully synthesized by the reduction of auric acid at 80°C, within 5 min of reaction. The biosynthesized gold and silver nanoparticles were characterized by techniques using various instruments, viz. ultraviolet-visible spectroscopy (UV-Vis spectroscopy), field emission transmission electron microscopy (FE-TEM), energy dispersive X-ray analysis (EDX), elemental mapping, and X-ray diffraction (XRD). In addition, the silver nanoparticles have shown antimicrobial potential against Bacillus anthracis, Vibrio parahaemolyticus, Staphylococcus aureus, Escherichia coli, and Bacillus cereus.

  6. Effect of Activated Charcoal on Rooting in Tissue Culture Seedling of Begonia fimbristipula on Dinghushan Mountain%活性炭对鼎湖山紫背天葵组培苗生根的影响

    Institute of Scientific and Technical Information of China (English)

    陈雄伟; 邵玲; 梁廉; 潘镇涛

    2012-01-01

    目的:以带有球茎的不定芽为外植体,探讨不同植物生长物质与活性炭(AC)对鼎湖山紫背天葵组培苗生根和移栽的影响.方法:组织培养单因子试验法.结果:NAA 0.3 mg/L+ IBA 0.2mg/L的组合较好地诱导球茎芽丛生根,但根数仍较少,根细、短小,幼小的不定芽萌发数量较多.添加300 mg/L活性炭明显提高生根质量并且抑制细芽点的分化,根数多达15.5条,根长范围在2.0~5.1 cm,根系发达,并且组培苗植株较高、球茎和叶片质量佳,生长健壮.将生根的组培苗带球茎分散为丛芽的形式移栽到泥炭土-珍珠岩(3∶1)的混合基质中,移栽后成活率达到100%,植株出苗快,长势旺盛.结论:以MS+蔗糖30 g/L+ NAA 0.3 mg/L+ IBA 0.2 mg/L+活性炭300mg/L+卡拉胶7.0 g/L作为紫背天葵组培苗的生根体系,是离体快繁和保存本地特色植物的有效途径.%Objective:To study the effect of different plant growth substance and activated charcoal on rooting in culture seedling of Begonia fimbristpula on Dinghushan mountain. Methods-. Tissue culture single factor experiment method was used. Results :NAA 0. 3 mg/L + IB A 0. 2 mg/L preferably induction adventitious bud clump with conn to take rooting, but the number of adventitious root were less,short and small,callow shoot more germination. 300 mg/L activated carbon obviously increased radicate quality and inhibited fine buds point differentiation,root number up to 15.5 institia,root length range was 2.0 - 5. 1 cm, root system developed. Tissue culture seedlings were higher,corm and leaf were good quality,strong growth. Took root of seedling cultivation with bulb for bush in the form of scattered bud planted to peat soil; perlite (3:1) mixed in matrix,after the transplant survival rate reached 100% ,plant form seedlings fast,grew exuberant. Conclusion; MS with sucrose 30 g/L + NAA 0. 3 mg/L + IBA 0. 2 mg/L + activated carbon 300 mg/L + carrag-eenan 7. 0 g/L as the tissue culture seedling

  7. Afrokoko Roots

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Give us a little background information about Afrokoko Roots.How long have you been performing together?It's an international Afrobeat outfit that I founded in Beijing three years ago.I founded it in order to show Chinese people that Africa is beyond what they see and hear on TV.For the purpose of cultural exchange,I hope it can help the Chinese learn about African culture,music,fashion,history and much more.Our band features two dancers,two backup singers,two percussionists,four brass players,a keyboard player,a guitar player and a drummer- and me as the lead vocal,drummer and dancer,which makes for live performances that are equally exciting sonically as they are visually.We have been traveling around,and so far,we have toured and performed in many Chinese cities such as Dalian (Liaoning Province),Hohhot (Inner Mongolia Autonomous Region) and Haikou (Hainan Province).

  8. Cassava root membrane proteome reveals activities during storage root maturation.

    Science.gov (United States)

    Naconsie, Maliwan; Lertpanyasampatha, Manassawe; Viboonjun, Unchera; Netrphan, Supatcharee; Kuwano, Masayoshi; Ogasawara, Naotake; Narangajavana, Jarunya

    2016-01-01

    Cassava (Manihot esculenta Crantz) is one of the most important crops of Thailand. Its storage roots are used as food, feed, starch production, and be the important source for biofuel and biodegradable plastic production. Despite the importance of cassava storage roots, little is known about the mechanisms involved in their formation. This present study has focused on comparison of the expression profiles of cassava root proteome at various developmental stages using two-dimensional gel electrophoresis and LC-MS/MS. Based on an anatomical study using Toluidine Blue, the secondary growth was confirmed to be essential during the development of cassava storage root. To investigate biochemical processes occurring during storage root maturation, soluble and membrane proteins were isolated from storage roots harvested from 3-, 6-, 9-, and 12-month-old cassava plants. The proteins with differential expression pattern were analysed and identified to be associated with 8 functional groups: protein folding and degradation, energy, metabolism, secondary metabolism, stress response, transport facilitation, cytoskeleton, and unclassified function. The expression profiling of membrane proteins revealed the proteins involved in protein folding and degradation, energy, and cell structure were highly expressed during early stages of development. Integration of these data along with the information available in genome and transcriptome databases is critical to expand knowledge obtained solely from the field of proteomics. Possible role of identified proteins were discussed in relation with the activities during storage root maturation in cassava.

  9. MicroRNA directs mRNA cleavage of the transcription factor NAC1 to downregulate auxin signals for arabidopsis lateral root development.

    Science.gov (United States)

    Guo, Hui-Shan; Xie, Qi; Fei, Ji-Feng; Chua, Nam-Hai

    2005-05-01

    Although several plant microRNAs (miRNAs) have been shown to play a role in plant development, no phenotype has yet been associated with a reduction or loss of expression of any plant miRNA. Arabidopsis thaliana miR164 was predicted to target five NAM/ATAF/CUC (NAC) domain-encoding mRNAs, including NAC1, which transduces auxin signals for lateral root emergence. Here, we show that miR164 guides the cleavage of endogenous and transgenic NAC1 mRNA, producing 3'-specific fragments. Cleavage was blocked by NAC1 mutations that disrupt base pairing with miR164. Compared with wild-type plants, Arabidopsis mir164a and mir164b mutant plants expressed less miR164 and more NAC1 mRNA and produced more lateral roots. These mutant phenotypes can be complemented by expression of the appropriate MIR164a and MIR164b genomic sequences. By contrast, inducible expression of miR164 in wild-type plants led to decreased NAC1 mRNA levels and reduced lateral root emergence. Auxin induction of miR164 was mirrored by an increase in the NAC1 mRNA 3' fragment, which was not observed in the auxin-insensitive mutants auxin resistant1 (axr1-12), axr2-1, and transport inhibitor response1. Moreover, the cleavage-resistant form of NAC1 mRNA was unaffected by auxin treatment. Our results indicate that auxin induction of miR164 provides a homeostatic mechanism to clear NAC1 mRNA to downregulate auxin signals.

  10. Changes in the level of ( sup 14 C)indole-3-acetic acid and ( sup 14 C)indoleacetylaspartic acid during root formation in mung bean cuttings. [Vigna radiata

    Energy Technology Data Exchange (ETDEWEB)

    Norcini, J.G.; Heuser, C.W. (Pennsylvania State Univ., University Park (USA))

    1988-04-01

    Changes in the levels of ({sup 14}C)indole-3-acetic acid (IAA) and ({sup 14}C)indoleacetylaspartic acid (IAAsp) were examined during adventitious root formation in mung bean (Vigna radiata (L.) R. Wilcz. Berken) stem cuttings. IAAsp was identified by GC-MS as the primary conjugate in IAA-treated cuttings. During root formation in IAA-treated cuttings, the level of ({sup 14}C)IAAsp increased rapidly the first day and then declined; ({sup 14}C)IAA was rapidly metabolized and not detected after 12 hours.

  11. A maize root tip system to study DNA replication programmes in somatic and endocycling nuclei during plant development.

    Science.gov (United States)

    Bass, Hank W; Wear, Emily E; Lee, Tae-Jin; Hoffman, Gregg G; Gumber, Hardeep K; Allen, George C; Thompson, William F; Hanley-Bowdoin, Linda

    2014-06-01

    The progress of nuclear DNA replication is complex in both time and space, and may reflect several levels of chromatin structure and 3-dimensional organization within the nucleus. To understand the relationship between DNA replication and developmental programmes, it is important to examine replication and nuclear substructure in different developmental contexts including natural cell-cycle progressions in situ. Plant meristems offer an ideal opportunity to analyse such processes in the context of normal growth of an organism. Our current understanding of large-scale chromosomal DNA replication has been limited by the lack of appropriate tools to visualize DNA replication with high resolution at defined points within S phase. In this perspective, we discuss a promising new system that can be used to visualize DNA replication in isolated maize (Zea mays L.) root tip nuclei after in planta pulse labelling with the thymidine analogue, 5-ethynyl-2'-deoxyuridine (EdU). Mixed populations of EdU-labelled nuclei are then separated by flow cytometry into sequential stages of S phase and examined directly using 3-dimensional deconvolution microscopy to characterize spatial patterns of plant DNA replication. Combining spatiotemporal analyses with studies of replication and epigenetic inheritance at the molecular level enables an integrated experimental approach to problems of mitotic inheritance and cellular differentiation.

  12. Rhabdovirus-like endogenous viral elements in the genome of Spodoptera frugiperda insect cells are actively transcribed: Implications for adventitious virus detection.

    Science.gov (United States)

    Geisler, Christoph; Jarvis, Donald L

    2016-07-01

    Spodoptera frugiperda (Sf) cell lines are used to produce several biologicals for human and veterinary use. Recently, it was discovered that all tested Sf cell lines are persistently infected with Sf-rhabdovirus, a novel rhabdovirus. As part of an effort to search for other adventitious viruses, we searched the Sf cell genome and transcriptome for sequences related to Sf-rhabdovirus. To our surprise, we found intact Sf-rhabdovirus N- and P-like ORFs, and partial Sf-rhabdovirus G- and L-like ORFs. The transcribed and genomic sequences matched, indicating the transcripts were derived from the genomic sequences. These appear to be endogenous viral elements (EVEs), which result from the integration of partial viral genetic material into the host cell genome. It is theoretically impossible for the Sf-rhabdovirus-like EVEs to produce infectious virus particles as 1) they are disseminated across 4 genomic loci, 2) the G and L ORFs are incomplete, and 3) the M ORF is missing. Our finding of transcribed virus-like sequences in Sf cells underscores that MPS-based searches for adventitious viruses in cell substrates used to manufacture biologics should take into account both genomic and transcribed sequences to facilitate the identification of transcribed EVE's, and to avoid false positive detection of replication-competent adventitious viruses.

  13. GENESIS AND DEVELOPMENT OF A “NONPARTISAN” POLITICAL ACTOR: The Formation of the Jama’ah Islah Malaysia (JIM and its Roots in Western Europe

    Directory of Open Access Journals (Sweden)

    Sophie Lemiere

    2009-02-01

    Full Text Available This paper looks at the genesis and development of the Jama’ah Islah Malaysia (JIM, a modernist-reformist Islamist organisation that today has played a vital and visible role in the political landscape of Malaysian politics. Little is known about the early genesis of JIM, and how it began in the 1970s and 1980s as a student-based cadre organisation, created by Malaysian Muslim students studying abroad in Europe and North America. JIM’s roots therefore lie in the Islamic Representative Council (IRC that was a semi-underground student-cadre movement that was created outside Malaysia, and which aimed to bring about the Islamisation of Malaysian society through the process of social and political mobilisation. Working through the archives of JIM today and interviewing the foundermembers of JIM and the IRC, this paper is the first historical account of the formation and development of IRC and JIM to be published. 

  14. Histological analysis of the callogenesis and organogenesis from root segments of Curcuma zedoaria Roscoe

    Directory of Open Access Journals (Sweden)

    Marcia O. Mello

    2001-06-01

    Full Text Available Callus was induced from root segments taken from in vitro grown plants of Curcuma zedoaria Roscoe. The explants were cultured on agar-solidified Murashige and Skoog medium supplemented with 13.4muM of alpha-naphthaleneacetic acid and 2.2muM of 6-benzylaminopurine at 25ºC in the dark. Histological analysis revealed that callus was formed from the hypertrophied cortical parenchyma cells of the explant. Some of these cells underwent division while the surrounding cells accumulated starch. Callus was capable of shoot bud regeneration after 70 days when it was transfered to liquid medium of the same composition. After 30 days in liquid medium, buds developed from nodular structures. The adventitious shoots developed extensive root systems when they were placed on agar-solidified Murashige and Skoog medium without growth regulators at 25º C in the light. The establishment of these plantlets in soil was about 95%.Calo de Curcuma zedoaria Roscoe foram induzidos a partir de segmentos de raízes de plantas cultivadas in vitro. Os explantes foram inoculados em meio de Murashige & Skoog solidificado com ágar e suplementado com 13,4miM de ácido alfa-naftaleno acético e 2,2miM de 6-benzilaminopurina e mantidos no escuro a 25°C. As análises histológicas realizadas revelaram que os callus eram formados a partir de células hipertrofiadas do parênquima cortical do explante. Algumas destas células entravam em divisão, enquanto as células vizinhas a estas acumulavam amido. Após 70 dias, calos transferidos para meio de Murashige & Skoog líquido de mesma composição, eram capazes de regenerar plantas. Após 30 dias em meio líquido, gemas se desenvolveram de estruturas nodulares. Estas gemas adventíceas formaram um abundante sistema radicular quando transferidas para meio de Murashige & Skoog solidificado com ágar, sem regulador de crescimento e mantidas a 25°C na luz. A taxa de sobrevivência das plantas foi de 95%.

  15. Over-expression of the Arabidopsis proton-pyrophosphatase AVP1 enhances transplant survival, root mass, and fruit development under limiting phosphorus conditions.

    Science.gov (United States)

    Yang, Haibing; Zhang, Xiao; Gaxiola, Roberto A; Xu, Guohua; Peer, Wendy Ann; Murphy, Angus S

    2014-07-01

    Phosphorus (P), an element required for plant growth, fruit set, fruit development, and fruit ripening, can be deficient or unavailable in agricultural soils. Previously, it was shown that over-expression of a proton-pyrophosphatase gene AVP1/AVP1D (AVP1DOX) in Arabidopsis, rice, and tomato resulted in the enhancement of root branching and overall mass with the result of increased mineral P acquisition. However, although AVP1 over-expression also increased shoot biomass in Arabidopsis, this effect was not observed in tomato under phosphate-sufficient conditions. AVP1DOX tomato plants exhibited increased rootward auxin transport and root acidification compared with control plants. AVP1DOX tomato plants were analysed in detail under limiting P conditions in greenhouse and field trials. AVP1DOX plants produced 25% (P=0.001) more marketable ripened fruit per plant under P-deficient conditions compared with the controls. Further, under low phosphate conditions, AVP1DOX plants displayed increased phosphate transport from leaf (source) to fruit (sink) compared to controls. AVP1DOX plants also showed an 11% increase in transplant survival (Ptomato cultivars for increased proton pyrophosphatase gene expression could be useful when selecting for cultivars to be grown on marginal soils.

  16. GiA Roots: software for the high throughput analysis of plant root system architecture

    OpenAIRE

    Galkovskyi Taras; Mileyko Yuriy; Bucksch Alexander; Moore Brad; Symonova Olga; Price Charles A; Topp Christopher N; Iyer-Pascuzzi Anjali S; Zurek Paul R; Fang Suqin; Harer John; Benfey Philip N; Weitz Joshua S

    2012-01-01

    Abstract Background Characterizing root system architecture (RSA) is essential to understanding the development and function of vascular plants. Identifying RSA-associated genes also represents an underexplored opportunity for crop improvement. Software tools are needed to accelerate the pace at which quantitative traits of RSA are estimated from images of root networks. Results We have developed GiA Roots (General Image Analysis of Roots), a semi-automated software tool designed specifically...

  17. Study on production of useful metabolites by development of advanced cell culture techniques using radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Byung Yeoup; Kim, Jin Hong; Lee, Seung Sik; Kim, Jae Sung; An, Byung Chull; Moon, Yu Ran; Lee, Eun Mi; Lee, Min Hee; Lee, Jae Tack [KAERI, Daejeon (Korea, Republic of)

    2010-02-15

    The purpose of this project is improvement of investigation, materialization and evaluation techniques on effectiveness for functional natural compounds throughout development of tissue/cell culture techniques for mass production of useful metabolites using radiation. Research scope includes 1) Development of a technique for radiation tissue and cell culture, 2) Database construction for radiation response in plants and radiation effects, 3) Construction of general-purpose national based techniques of cell culture technique using radiation. Main results are as follow: mass culture of the adventitious roots of mountain ginseng (Panax ginseng C. A. Meyer) roots using rare earth elements in bioreactor: characterization of a transcription factor EoP gene from centipedegrass and the transcription regulation of LexA from Synechocystis sp PCC6803 and E. coli: identification of gamma-ray induced hydrogenase synthesis in hox gene transformed E. coli: transformation and the selection of the EoP transgene from Arabidopsis, rice and lettuce: Identification of the maysin and maysin derivatives in centipedegrass: characterization of gamma-ray induced color change in Taxus cuspidata: verification of the expression of antioxidant proteins (POD, APX and CAT) to gamma-ray in Arabidopsis: comparison of the response of the expression level to gamma-ray or H{sub 2}O{sub 2} in Arabidopsis; verification of the responses and effects to gamma-ray from plants (analysis of NPQ and ROS levels): the development method for rapidly enhancing maysin content of centipede grass; establishment of mass culture system for red beet

  18. Sampling Strategies for Evaluating the Rate of Adventitious Transgene Presence in Non-Genetically Modified Crop Fields.

    Science.gov (United States)

    Makowski, David; Bancal, Rémi; Bensadoun, Arnaud; Monod, Hervé; Messéan, Antoine

    2017-02-23

    According to E.U. regulations, the maximum allowable rate of adventitious transgene presence in non-genetically modified (GM) crops is 0.9%. We compared four sampling methods for the detection of transgenic material in agricultural non-GM maize fields: random sampling, stratified sampling, random sampling + ratio reweighting, random sampling + regression reweighting. Random sampling involves simply sampling maize grains from different locations selected at random from the field concerned. The stratified and reweighting sampling methods make use of an auxiliary variable corresponding to the output of a gene-flow model (a zero-inflated Poisson model) simulating cross-pollination as a function of wind speed, wind direction, and distance to the closest GM maize field. With the stratified sampling method, an auxiliary variable is used to define several strata with contrasting transgene presence rates, and grains are then sampled at random from each stratum. With the two methods involving reweighting, grains are first sampled at random from various locations within the field, and the observations are then reweighted according to the auxiliary variable. Data collected from three maize fields were used to compare the four sampling methods, and the results were used to determine the extent to which transgene presence rate estimation was improved by the use of stratified and reweighting sampling methods. We found that transgene rate estimates were more accurate and that substantially smaller samples could be used with sampling strategies based on an auxiliary variable derived from a gene-flow model.

  19. Efeito do AIB sobre o enraizamento e desenvolvimento de estacas de quivi (Actinidia deliciosa Effect of IBA on the rooting and development of kiwi cuttings (Actinidia deliciosa

    Directory of Open Access Journals (Sweden)

    Vitor Manfroi

    1997-03-01

    Full Text Available O objetivo do trabalho foi estudar o efeito do ácido 3-indoibiitirico (A/B no enraizamento e desenvolvimento de estacas semi-lenhosas de quivi, cv. Monte. O experimento foi conduzido na Estação Experimental Agronômica da UFRGS, em Eldorado do Sul, RS, e constou de cinco tratamentos, com cinco repetições, em blocos casualizados. Usou-se 19 sacos/parcela, com duas estacas/saco plástico, plantadas em uma mistura argila: areia.-esterco (1: 1: 1: e tratadas com AIB nas concentrações de: 2000ppm, 4000ppm, 6000ppm e 8000ppm, além da testemunha (sem AIB. O AIB não influenciou na porcentagem de enraizamento das estacas, mas resultou no aumento linear do peso seco médio das raízes. Houve, da mesma forma, incrementos lineares no comprimento e no peso seco dos brotos, à medida que se elevou a concentração de AIB.The objective of this experiment was to study the effect of the 3-indolbutiric acid (IBA on the rooting and development of semi-hardwood cuttings of kiwi, cv. Monty. The experiment was carried out at the Staccatos Experimental Agronomical/UFRGS in Eldorado do Soul. RS, Brazil with five treatments and five repetitions, in completely randomized blocks design. There were 19 bags per pilot with two cuttings per plastic bag grow in a catty: sane manure mixture (1:1:1 and treated by /BA at the concentrations of 2000ppm, 4000ppm, 6000ppm and 8000ppm. In addition to the contrail. IBA did not affect the rooting percentage but resulted in a linear increase of the mean root dry weight. Shoot development was not affected by the IBA. Buy there was a tendency for a linear increase of shoot length and dry weight in response to IBA concentrations above 2000 ppm.

  20. Root canal

    Science.gov (United States)

    ... 2016 Updated by: Michael Kapner, DDS, general and aesthetic dentistry, Norwalk Medical Center, Norwalk, CT. Review provided ... for EHRs For Developers U.S. National Library of Medicine 8600 Rockville Pike, Bethesda, MD 20894 U.S. Department ...

  1. Neovascularization of coronary tunica intima (DIT is the cause of coronary atherosclerosis. Lipoproteins invade coronary intima via neovascularization from adventitial vasa vasorum, but not from the arterial lumen: a hypothesis

    Directory of Open Access Journals (Sweden)

    Subbotin Vladimir M

    2012-04-01

    often develops at high blood LDL-C levels; (3 apparent CA can develop at lowered blood LDL-C levels. This mechanism is not unique to the coronary artery: for instance, the normally avascular cornea accumulates lipoproteins after neovascularization, resulting in lipid keratopathy. Hypothesis Neovascularization of the normally avascular coronary DIT by permeable vasculature from the adventitial vasa vasorum is the cause of LDL deposition and CA. DIT enlargement, seen in early CA and aging, causes hypoxia of the outer DIT and induces neovascularization. According to this alternative proposal, coronary atherosclerosis is not related to inflammation and can occur in individuals with normal circulating levels of LDL, consistent with research findings.

  2. Underground riparian wood: Reconstructing the processes influencing buried stem and coarse root structures of Black Poplar (Populus nigra L.)

    Science.gov (United States)

    Holloway, James V.; Rillig, Matthias C.; Gurnell, Angela M.

    2017-02-01

    Following analysis of morphological (including dendrochronological and sedimentological) aspects of buried stem and coarse root structures of eight mature P. nigra individuals located within two sites along the middle to lower Tagliamento River, Italy (Holloway et al., in press), this paper introduces information on the historical processes of vegetation development and river flow and links this to the form of these eight trees. Aerial images and flow time series are assembled to reconstruct the flood history, potential recruitment periods, and vegetation cover development in the vicinity of the studied trees. This information is combined with previous morphological evidence to reconstruct the development history of each tree via three-element summary diagrams showing (i) a time series of floods, aerial imagery dates, and potential recruitment periods, with colour-coded bars indicating likely key stages in the development of the tree; (ii) colour-coded overlays on an SfM photogrammetric model of each tree; and (iii) colour-coded text boxes providing explanatory annotations. The combined morphology-process analysis reveals complex three-dimensional underground structures, incorporating buried stems, shoots, and adventitious roots that are sometimes joined by grafting, linking the standing tree with the buried gravel surface on which it was recruited. Analysis of process data provides a firm basis for identifying and dating influential flow disturbance events and recruitment windows and shows that a relatively small number of flood events have significantly impacted the studied trees, which are mainly but not exclusively the largest floods in the record. Nevertheless, we stress that all suggested dates are best estimates in the light of the combined evidence. There is undoubted potential for building different interpretations of belowground woody structure development in light of such evidence, but we feel that the form and timing of the developmental trajectories we

  3. Symbiotic leghemoglobins are crucial for nitrogen fixation in legume root nodules but not for general plant growth and development

    DEFF Research Database (Denmark)

    Ott, Thomas; van Dongen, Joost T; Günther, Catrin

    2005-01-01

    fixation (SNF). In legumes, SNF occurs in specialized organs, called nodules, which contain millions of nitrogen-fixing rhizobia, called bacteroids. The induction of nodule-specific plant genes, including those encoding symbiotic leghemoglobins (Lb), accompanies nodule development. Leghemoglobins...

  4. 发展人为本立校德为先%On People-oriented and Morality-rooted School Development

    Institute of Scientific and Technical Information of China (English)

    刘希华

    2016-01-01

    教育理念是群体思维和集体智慧,它是一种抽象的无时不在的文化传统,学校发展的教育理念有三个关键点:一是以人为本是发展的根本;二是校园文化是发展的统领;三是创新精神是发展的动力。%Education idea is a kind of group thinking and collective intelligence as well as an abstract cultural tradition surrounding us. There are three key points in the education idea developed by school: firstly, people oriented concept is the fundamental of development; secondly, campus culture is the direction of development; thirdly, innovative spirit is the motive force of development.

  5. Determinants of Aortic Root Dilatation and Reference Values Among Young Adults Over a 20-Year Period: Coronary Artery Risk Development in Young Adults Study.

    Science.gov (United States)

    Teixido-Tura, Gisela; Almeida, Andre L C; Choi, Eui-Young; Gjesdal, Ola; Jacobs, David R; Dietz, Harry C; Liu, Kiang; Sidney, Stephen; Lewis, Cora E; Garcia-Dorado, David; Evangelista, Artur; Gidding, Samuel; Lima, João A C

    2015-07-01

    Aortic size increases with age, but factors related to such dilatation in healthy young adult population have not been studied. We aim to evaluate changes in aortic dimensions and its principal correlates among young adults over a 20-year time period. Reference values for aortic dimensions in young adults by echocardiography are also provided. Healthy Coronary Artery Risk Development in Young Adults (CARDIA) study participants aged 23 to 35 years in 1990-1991 (n=3051) were included after excluding 18 individuals with significant valvular dysfunction. Aortic root diameter (ARD) by M-mode echocardiography at year-5 (43.7% men; age, 30.2 ± 3.6 years) and year-25 CARDIA exams was obtained. Univariable and multivariable analyses were performed to assess associations of ARD with clinical data at years-5 and -25. ARD from year-5 was used to establish reference values of ARD in healthy young adults. ARD at year-25 was greater in men (33.3 ± 3.7 versus 28.7 ± 3.4 mm; P<0.001) and in whites (30.9 ± 4.3 versus 30.5 ± 4.1 mm; P=0.006). On multivariable analysis, ARD at year-25 was positively correlated with male sex, white ethnicity, age, height, weight, 20-year gain in weight, active smoking at baseline, and 20-year increase in diastolic, systolic, and mean arterial pressure. A figure showing the estimated 95th percentile of ARD by age and body surface area stratified by race and sex is provided. This study demonstrates that smoking, blood pressure, and increase in body weight are the main modifiable correlates of aortic root dilation during young adulthood. Our study also provides reference values for ARD in young adults.

  6. Bench heating for potplant cultivation: analysis of effects of root- and airtemperature on growth, development and production.

    NARCIS (Netherlands)

    Vogelezang, J.V.M.

    1993-01-01

    This thesis deals with the application of bench heating systems for potplant cultivation, which were developed for application of low temperature heating water from flue gas condensers and external waste heat sources. Compared to the traditional way of heating, a 'reversed' temperature gradient is c

  7. Analysis of Poverty Performance and Its Rooted Causes of the Aid-Poverty-Development Counties in Sichuan

    Institute of Scientific and Technical Information of China (English)

    ShenMao-ying

    2003-01-01

    There are 36 counties affirmed to be aid-poverty-development county in the early 21st century, which distribute around the circumferential mountain of Sichuan Basin,According to the topographic features and the distribution of nationality, these aid-poverty-development counties can be classified into 4 depressed-regions. Study shows that regional poverty performance of 4 depressed-regions not only has many commons in the field of regional economic structure and industry structure, which is far behind the average development performance of Sichuan in the field of economic sum per capita such as GDP, farmer net income per capita as well as retail scale consumer goods, it is also quite different related to infrastructure and social development within 4 depressed-regions. Regional Poverty is chronically resulted in interaction of the multi-factors. Natural condition constraint is the basic factor contributed to regional poverty, policy influences play key role, the poor culture is inherent factor to regional poverty and the marginal locations play important role.

  8. Analysis of Poverty Performance and Its Rooted Causes of the Aid-Poverty-Development Counties in Sichuan

    Institute of Scientific and Technical Information of China (English)

    Shen Mao-ying

    2003-01-01

    There are 36 counties affirmed to be aid-poverty-development county in the early 21st century, which distribute around the circumferential mountain of Sichuan Basin.According to the topographic features and the distribution of nationality, these aid-poverty-development counties can be classified into 4 depressed-regions. Study shows that regional poverty performance of 4 depressed-regions not only has many commons in the field of regional economic structure and industry structure, which is far behind the average development performance of Sichuan in the field of economic sum per capita such as GDP, farmer net income per capita as well as retail scale consumer goods, it is also quite different related to infrastructure and social development within 4 depressed-regions. Regional Poverty is chronically resulted in interaction of the multi-factors. Natural condition constraint is the basic factor contributed to regional poverty, policy influences play key role, the poor culture is inherent factor to regional poverty and the marginal locations play important role.

  9. Development and characterization of 11 microsatellite markers in the root-gall-forming weevil, Ceutorhynchus assimilis (Coleoptera: Curculionidae)

    Science.gov (United States)

    The host race of Ceutorhynchus assimilis (Coleoptera: Curculionidae) that specifically develops on Lepidium draba (Brassicales: Brassicaceae), an invasive weed in North America, is being considered for use as a biocontrol agent. Because there are other races that attack other plants, it is important...

  10. Measuring Empathy in the 21st Century: Development of an Empathy Index Rooted in Social Cognitive Neuroscience and Social Justice

    Science.gov (United States)

    Gerdes, Karen E.; Lietz, Cynthia A.; Segal, Elizabeth A.

    2011-01-01

    Instruments currently being used to measure empathy do not reflect the recent neuroscientific scholarship on mirror neurons and the importance of self-awareness and emotion regulation in experiencing the fullest extent of empathy. The authors describe a theoretical framework for the initial development and pilot application of an empathy…

  11. D-Root: a system for cultivating plants with the roots in darkness or under different light conditions.

    Science.gov (United States)

    Silva-Navas, Javier; Moreno-Risueno, Miguel A; Manzano, Concepción; Pallero-Baena, Mercedes; Navarro-Neila, Sara; Téllez-Robledo, Bárbara; Garcia-Mina, Jose M; Baigorri, Roberto; Gallego, Francisco Javier; del Pozo, Juan C

    2015-10-01

    In nature roots grow in the dark and away from light (negative phototropism). However, most current research in root biology has been carried out with the root system grown in the presence of light. Here, we have engineered a device, called Dark-Root (D-Root), to grow plants in vitro with the aerial part exposed to the normal light/dark photoperiod while the roots are in the dark or exposed to specific wavelengths or light intensities. D-Root provides an efficient system for cultivating a large number of seedlings and easily characterizing root architecture in the dark. At the morphological level, root illumination shortens root length and promotes early emergence of lateral roots, therefore inducing expansion of the root system. Surprisingly, root illumination also affects shoot development, including flowering time. Our analyses also show that root illumination alters the proper response to hormones or abiotic stress (e.g. salt or osmotic stress) and nutrient starvation, enhancing inhibition of root growth. In conclusion, D-Root provides a growing system closer to the natural one for assaying Arabidopsis plants, and therefore its use will contribute to a better understanding of the mechanisms involved in root development, hormonal signaling and stress responses.

  12. Response of winter root starch concentration to severe water stress and fruit load and its subsequent effects on early peach fruit development.

    Science.gov (United States)

    Lopez, Gerardo; Girona, Joan; Marsal, Jordi

    2007-11-01

    Effect of water stress during stage III of peach fruit development on winter root starch concentration (RSC) and subsequent reproductive development was studied. Two irrigation treatments were applied in two consecutive seasons (2003-2004): full irrigation (FI) and no irrigation during stage III of fruit development until visible leaf wilting (LWI), which occurred when midday stem water potential reached -1.80 MPa. Three fruit thinning intensities were applied within each irrigation treatment. The year 2005 was a recovery year in which all trees received full irrigation and commercial fruit thinning. Water deficit and high fruit loads in the previous season significantly reduced the concentration of winter RSC. Fruit set and fruit growth from full bloom to 30 days after full bloom (30 DAFB) increased with increasing winter RSC before other factors, such as inter-fruit competition and availability of carbon from current photosynthesis, came into play. Consequently, severe water stress reduced the total number of fruits and fruit dry mass growth 30 DAFB. However, during the recovery year and after fruit thinning, fruit loads were similar between irrigation treatments and yield capacity remained unaffected. Peach fruit production recovered quickly from the deleterious effects of two consecutive years of water stress because of a combination of two factors: (1) reduced initial fruit set that was still adequate to achieve a commercial crop; and (2) the low sensitivity of fruit growth 30 DAFB to winter RSC.

  13. 3种观叶植物水生性根系形成及NAA处理效应%Development of Aquatic-like Roots of Three Foliage Plants in Hydroculture and Effects of α-Naphthaleneacetic acid ( NAA ) on Rooting

    Institute of Scientific and Technical Information of China (English)

    王代容; 刘晓荣; 陈敏; 李妙汉; 廖飞雄

    2011-01-01

    The development of the aquatic -like roots of three foliage plants Pachira macrocarpa, Dracaena deremensis 'Corapacta' and Agave americana and the effects of different concentrations of a-Naphthaleneacetic acid (NAA) on rooting were investigated as potted in hydroculture. The results showed that three foliage plants initiated the roots at 9.7, 14.4 and 3.5 d respectively hydroculture on and reached the peak of rooting at 40* day, while P. Macrocarpe produced the most of roots to the first 20 d of the hydroculture. The root of A. Americana stopped increasing in length at about 20 d of the hydroculture, but the roots of other two plants kept growing as hydroculture continued. The maximum root diameters were measured at 20 d for P. Macrocarpaand A. Americana and at 40 d for D. Deremensis 'Compacta'. However, The Root of three plants were found to shrink in diameter after 20 d or 40 d. NAA treatment with the concentrations of 100、 200 and 300 mg/L increased root number significantly and the optimal concentration was 200 mg/L for three plants. NAA treatments delayed the root formation of P. Macrocarpa and A. Americana and decreased root growth velocity. Compared to the control the aquatic-like roots of three plants with NAA treatments were shorter in length and bigger in diameter.%研究发财树、螺纹铁和龙舌兰3种观叶植物水培中水生性根系发生与生长特性、NAA的诱导效应.结果表明,3种植物分别在水培后的第9.7、14.4和3.5 d开始出根,40 d左右发根数达到最高峰,其中发财树在水培后的前20d就产生大部分根系.龙舌兰的根在20d左右就达最长,其它2种植物根的生长随时间延长而增长.发财树、龙舌兰培养到20 d,螺纹铁培养到40 d,水生性根的基部粗度达到最大,但之后3种植物水生性根系基部径粗均会出现不同程度的缩小.不同浓度NAA(100、200和300mg/L)处理可提高3种植物根系产生的数量,以200mg/L NAA处理产生的根数最多;NAA

  14. Gladiolus development in response to bulb treatment with different concentrations of humic acids

    Directory of Open Access Journals (Sweden)

    Marihus Altoé Baldotto

    2013-02-01

    Full Text Available Gladiolus is an ornamental species produced for cut flowers and propagated by corms. The early flowering and increase in the number of flower buds, besides the production of commercial corms are constant challenges to be addressed in the crop improvement. Commercial production of ornamentals is technologically accelerated by means of growth regulators. Among them, the auxins stand out for their key role in the adventitious rooting and cell elongation. Alternatively, the humic substances present in the organic matter also have biostimulating effect, which is very similar to the auxinic effect. Therefore, this work aimed to study the growth and development of gladiolus in response to application of different concentrations of humic acids (HA isolated from vermicompost. Corms were soaked for 24 hours in solutions containing 0, 10, 20, 30 and 40 mmol L-1 of C from HA. The corms were planted in 10-dm³ plastic bags filled with substrate and kept in a greenhouse. Growth of shoots and roots was evaluated. The results showed that the use of HA accelerates growth, and anticipates and increases flowering of Gladiolus.

  15. The Meaning of Roots: How a Migrant Farmworker Student Developed a Bilingual-Bicultural Identity Through Change

    Directory of Open Access Journals (Sweden)

    Robin L. Danzak

    2015-04-01

    Full Text Available Abstract Thousands of children and teens labor as migrant farmworkers across the United States. These youngsters, many who are immigrants, face challenges in completing their education and breaking the cycle of agricultural work. Such barriers are influenced by geographic instability, poverty, and sociocultural marginalization. Beyond these factors, and the focus of this article, is the challenge of bilingual-bicultural identity negotiation experienced by young farmworkers in and out of the educational context. This question is explored through the case study of Manuel (a pseudonym, a teen farmworker in Florida. Manuel emigrated from Mexico at the age of 12, and is a speaker of Spanish, Otomi (an indigenous language, and English. Although he recently completed high school, he struggled to adjust to life in the U.S. and acquire English. Manuel provided interviews and autobiographical writing in 2008, when he was age 14 (grade 8, and again in 2012, when he was 18 (grade 11. His parents, also migrant farmworkers, contributed an interview in 2012. A qualitative, thematic analysis was applied to the data. Themes that emerged included: resistance and acceptance of personal and cultural-linguistic change, the need to acostumbrarse (get used to it with respect to these changes, the desire to salir adelante (get ahead and the pathways to do so (e.g., finish school, learn English, and Manuel’s developing bilingualism and his shifting attitudes towards it. Overall, Manuel’s story offers deep insights into the realities in which the bilingual-bicultural social identity of a migrant farmworker student develops and interacts in and out of school settings.

  16. The Meaning of Roots: How a Migrant Farmworker Student Developed a Bilingual-Bicultural Identity Through Change

    Directory of Open Access Journals (Sweden)

    Robin L. Danzak

    2015-04-01

    Full Text Available Thousands of children and teens labor as migrant farmworkers across the United States. These youngsters, many who are immigrants, face challenges in completing their education and breaking the cycle of agricultural work. Such barriers are influenced by geographic instability, poverty, and sociocultural marginalization. Beyond these factors, and the focus of this article, is the challenge of bilingual-bicultural identity negotiation experienced by young farmworkers in and out of the educational context. This question is explored through the case study of Manuel (a pseudonym, a teen farmworker in Florida. Manuel emigrated from Mexico at the age of 12, and is a speaker of Spanish, Otomi (an indigenous language, and English. Although he recently completed high school, he struggled to adjust to life in the U.S. and acquire English. Manuel provided interviews and autobiographical writing in 2008, when he was age 14 (grade 8, and again in 2012, when he was 18 (grade 11. His parents, also migrant farmworkers, contributed an interview in 2012. A qualitative, thematic analysis was applied to the data. Themes that emerged included: resistance and acceptance of personal and cultural-linguistic change, the need to acostumbrarse (get used to it with respect to these changes, the desire to salir adelante (get ahead and the pathways to do so (e.g., finish school, learn English, and Manuel’s developing bilingualism and his shifting attitudes towards it. Overall, Manuel’s story offers deep insights into the realities in which the bilingual-bicultural social identity of a migrant farmworker student develops and interacts in and out of school settings.

  17. Transient silencing mediated by in vitro synthesized double-stranded RNA indicates that PsCdc14 is required for sporangial development in a soybean root rot pathogen.

    Science.gov (United States)

    Zhao, Wei; Yang, Xinyu; Dong, Suomeng; Sheng, Yuting; Wang, Yuanchao; Zheng, Xiaobo

    2011-12-01

    In many eukaryotic organisms, Cdc14 phosphatase regulates multiple biological events during anaphase and is essential for mitosis. It has been shown that Cdc14 is required for sporulation in the potato blight pathogen Phytophthora infestans; however, the role that the Cdc14 homolog (PsCdc14) plays in the soil-borne soybean root rot pathogen P. sojae remains ambiguous. PsCdc14 is highly expressed in sporulation, zoospore, and cyst life stages, but not in vegetative mycelia and infection stages, suggesting that it contributes to asexual reproduction and thus the spread of the disease. Double-stranded RNA (dsRNA) mediates gene silencing, a post-transcriptional and highly conserved process in eukaryotes, involving specific gene silencing through degradation of target mRNA. We combined in vitro dsRNA synthesis and a polyethylene glycol-mediated transformation system to construct a dsRNA-mediated transient gene silencing system; and then performed a functional analysis of PsCdc14 in P. sojae. PsCdc14 mRNA was dramatically reduced in transformants after protoplasts were exposed in in vitro synthesized PsCdc14 dsRNA, resulting in low sporangial production and abnormal development in P. sojae silencing lines. Furthermore, dsRNA-mediated transient gene silencing could enable elucidation of P. sojae rapid gene function, facilitating our understanding of the development and pathogenicity mechanisms of this oomycete fungus.

  18. Functional upregulation of nav1.8 sodium channels on the membrane of dorsal root Ganglia neurons contributes to the development of cancer-induced bone pain.

    Directory of Open Access Journals (Sweden)

    Xiao-Dan Liu

    Full Text Available We have previously reported that enhanced excitability of dorsal root ganglia (DRG neurons contributes to the development of bone cancer pain, which severely decreases the quality of life of cancer patients. Nav1.8, a tetrodotoxin-resistant (TTX-R sodium channel, contributes most of the sodium current underlying the action potential upstroke and accounts for most of the current in later spikes in a train. We speculate that the Nav1.8 sodium channel is a potential candidate responsible for the enhanced excitability of DRG neurons in rats with bone cancer pain. Here, using electrophysiology, Western blot and behavior assays, we documented that the current density of TTX-R sodium channels, especially the Nav1.8 channel, increased significantly in DRG neurons of rats with cancer-induced bone pain. This increase may be due to an increased expression of Nav1.8 on the membrane of DRG neurons. Accordantly, blockade of Nav1.8 sodium channels by its selective blocker A-803467 significantly alleviated the cancer-induced mechanical allodynia and thermal hyperalgesia in rats. Taken together, these results suggest that functional upregulation of Nav1.8 channels on the membrane of DRG neurons contributes to the development of cancer-induced bone pain.

  19. Defining multiple, distinct, and shared spatiotemporal patterns of DNA replication and endoreduplication from 3D image analysis of developing maize (Zea mays L.) root tip nuclei.

    Science.gov (United States)

    Bass, Hank W; Hoffman, Gregg G; Lee, Tae-Jin; Wear, Emily E; Joseph, Stacey R; Allen, George C; Hanley-Bowdoin, Linda; Thompson, William F

    2015-11-01

    Spatiotemporal patterns of DNA replication have been described for yeast and many types of cultured animal cells, frequently after cell cycle arrest to aid in synchronization. However, patterns of DNA replication in nuclei from plants or naturally developing organs remain largely uncharacterized. Here we report findings from 3D quantitative analysis of DNA replication and endoreduplication in nuclei from pulse-labeled developing maize root tips. In both early and middle S phase nuclei, flow-sorted on the basis of DNA content, replicative labeling was widely distributed across euchromatic regions of the nucleoplasm. We did not observe the perinuclear or perinucleolar replicative labeling patterns characteristic of middle S phase in mammals. Instead, the early versus middle S phase patterns in maize could be distinguished cytologically by correlating two quantitative, continuous variables, replicative labeling and DAPI staining. Early S nuclei exhibited widely distributed euchromatic labeling preferentially localized to regions with weak DAPI signals. Middle S nuclei also exhibited widely distributed euchromatic labeling, but the label was preferentially localized to regions with strong DAPI signals. Highly condensed heterochromatin, including knobs, replicated during late S phase as previously reported. Similar spatiotemporal replication patterns were observed for both mitotic and endocycling maize nuclei. These results revealed that maize euchromatin exists as an intermingled mixture of two components distinguished by their condensation state and replication timing. These different patterns might reflect a previously described genome organization pattern, with "gene islands" mostly replicating during early S phase followed by most of the intergenic repetitive regions replicating during middle S phase.

  20. A NOTE ON THE STOCHASTIC ROOTS OF STOCHASTIC MATRICES

    Institute of Scientific and Technical Information of China (English)

    Qi-Ming HE; Eldon GUNN

    2003-01-01

    In this paper, we study the stochastic root matrices of stochastic matrices. All stochastic roots of 2×2 stochastic matrices are found explicitly. A method based on characteristic polynomial of matrix is developed to find all real root matrices that are functions of the original 3×3 matrix, including all possible (function) stochastic root matrices. In addition, we comment on some numerical methods for computing stochastic root matrices of stochastic matrices.

  1. Methyl Jasmonate and Salicylic Acid Induced Oxidative Stress and Accumulation of Phenolics in Panax ginseng Bioreactor Root Suspension Cultures

    Directory of Open Access Journals (Sweden)

    Kee-Yoeup Paek

    2007-03-01

    Full Text Available To investigate the enzyme variations responsible for the synthesis of phenolics, 40 day-old adventitious roots of Panax ginseng were treated with 200 μM methyl jasmonate (MJ or salicylic acid (SA in a 5 L bioreactor suspension culture (working volume 4 L. Both treatments caused an increase in the carbonyl and hydrogen peroxide (H2O2 contents, although the levels were lower in SA treated roots. Total phenolic, flavonoid, ascorbic acid, non-protein thiol (NPSH and cysteine contents and 1,1-diphenyl-2-picrylhydrazyl (DPPH radical reducing activity were increased by MJ and SA. Fresh weight (FW and dry weight (DW decreased significantly after 9 days of exposure to SA and MJ. The highest total phenolics (62%, DPPH activity (40%, flavonoids (88%, ascorbic acid (55%, NPSH (33%, and cysteine (62% contents compared to control were obtained after 9 days in SA treated roots. The activities of glucose 6-phosphate dehydrogenase, phenylalanine ammonia lyase, substrate specific peroxidases (caffeic acid peroxidase, quercetin peroxidase and ferulic acid peroxidase were higher in MJ treated roots than the SA treated ones. Increased shikimate dehydrogenase, chlorogenic acid peroxidase and β-glucosidase activities and proline content were observed in SA treated roots than in MJ ones. Cinnamyl alcohol dehydrogenase activity remained unaffected by both MJ and SA. These results strongly indicate that MJ and SA induce the accumulation of phenolic compounds in ginseng root by altering the phenolic synthesis enzymes.

  2. Alfalfa transgene dispersal and adventitious presence: understanding grower perception of risk

    Science.gov (United States)

    Recognizing the importance of coexistence, the alfalfa industry has developed a set of Best Management Practices (BMP) to maintain separation of GE and conventional production. But the success of BMP depends upon the degree that growers comply. Therefore we surveyed 530 alfalfa hay and seed producer...

  3. Shoot regeneration from GUS-transformed tomato (Lycopersicon esculentum) hairy root.

    Science.gov (United States)

    Moghaieb, Reda E A; Saneoka, Hirofumi; Fujita, Kounosuke

    2004-01-01

    To study the influence of genetic background on the transformation and regeneration of cultivated tomato plants, hairy root lines of tomato (Lycopersicon esculentum) were obtained by inoculating the hypocotyl explants of three tomato cultivars with the Agrobacterium rhizogenes strain DCAR-2, which harbors the pBI-121 binary vector. The Ri-T-DNA transformation into the plant DNA was confirmed by both of mikimopine and GUS assay analyses. The regeneration efficiency from hairy root explants was assessed. The data indicated that white embryonic calli were formed within two weeks in the presence of 2 mgl(-1) 2, 4-D plus 0.25 mgl(-1) kinetin. Adventitious shoots emerged from the embryonic callus in the presence of 1 mgl(-1) GA3 along with 0.5 mgl(-1) NAA. The regeneration frequency was higher in the cultivar UC-97, followed by Momotaro and then Edkawi. Molecular confirmation of the integration of the GUS gene into the hairy root-derived plants genomes was done via PCR using GUS-specific primers and also using Southern blotting analysis. Our data shows that regeneration is possible from hairy roots of the cultivated tomato and this system could be used to produce transgenic tomato plants expressing the genes present in Agrobacterium rhizogenes binary vectors.

  4. WHY ROOTING FAILS.

    Energy Technology Data Exchange (ETDEWEB)

    CREUTZ,M.

    2007-07-30

    I explore the origins of the unphysical predictions from rooted staggered fermion algorithms. Before rooting, the exact chiral symmetry of staggered fermions is a flavored symmetry among the four 'tastes.' The rooting procedure averages over tastes of different chiralities. This averaging forbids the appearance of the correct 't Hooft vertex for the target theory.

  5. The Root Canal Biofilm

    NARCIS (Netherlands)

    Sluis, van der L.W.M.; Boutsioukis, C.; Jiang, L.M.; Macedo, R.; Verhaagen, B.; Versluis, M.; Chávez de Paz, E.; Sedgley, C.M.; Kishen, A.

    2015-01-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm), and their products from the root canal wall, their removal out of the root cana

  6. Root canal irrigation

    NARCIS (Netherlands)

    L. van der Sluis; C. Boutsioukis; L.M. Jiang; R. Macedo; B. Verhaagen; M. Versluis

    2015-01-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm), and their products from the root canal wall, their removal out of the root cana

  7. Rooting gene trees without outgroups: EP rooting.

    Science.gov (United States)

    Sinsheimer, Janet S; Little, Roderick J A; Lake, James A

    2012-01-01

    Gene sequences are routinely used to determine the topologies of unrooted phylogenetic trees, but many of the most important questions in evolution require knowing both the topologies and the roots of trees. However, general algorithms for calculating rooted trees from gene and genomic sequences in the absence of gene paralogs are few. Using the principles of evolutionary parsimony (EP) (Lake JA. 1987a. A rate-independent technique for analysis of nucleic acid sequences: evolutionary parsimony. Mol Biol Evol. 4:167-181) and its extensions (Cavender, J. 1989. Mechanized derivation of linear invariants. Mol Biol Evol. 6:301-316; Nguyen T, Speed TP. 1992. A derivation of all linear invariants for a nonbalanced transversion model. J Mol Evol. 35:60-76), we explicitly enumerate all linear invariants that solely contain rooting information and derive algorithms for rooting gene trees directly from gene and genomic sequences. These new EP linear rooting invariants allow one to determine rooted trees, even in the complete absence of outgroups and gene paralogs. EP rooting invariants are explicitly derived for three taxon trees, and rules for their extension to four or more taxa are provided. The method is demonstrated using 18S ribosomal DNA to illustrate how the new animal phylogeny (Aguinaldo AMA et al. 1997. Evidence for a clade of nematodes, arthropods, and other moulting animals. Nature 387:489-493; Lake JA. 1990. Origin of the metazoa. Proc Natl Acad Sci USA 87:763-766) may be rooted directly from sequences, even when they are short and paralogs are unavailable. These results are consistent with the current root (Philippe H et al. 2011. Acoelomorph flatworms are deuterostomes related to Xenoturbella. Nature 470:255-260).

  8. [Dimensional fractal of post-paddy wheat root architecture].

    Science.gov (United States)

    Chen, Xin-xin; Ding, Qi-shuo; Li, Yi-nian; Xue, Jin-lin; Lu, Ming-zhou; Qiu, Wei

    2015-06-01

    To evaluate whether crop rooting system was directionally dependent, a field digitizer was used to measure post-paddy wheat root architectures. The acquired data was transferred to Pro-E, in which virtual root architecture was reconstructed and projected to a series of planes each separated in 10° apart. Fractal dimension and fractal abundance of root projections in all the 18 planes were calculated, revealing a distinctive architectural distribution of wheat root in each direction. This strongly proved that post-paddy wheat root architecture was directionally dependent. From seedling to turning green stage, fractal dimension of the 18 projections fluctuated significantly, illustrating a dynamical root developing process in the period. At the jointing stage, however, fractal indices of wheat root architecture resumed its regularity in each dimension. This wheat root architecture recovered its dimensional distinctness. The proposed method was applicable for precision modeling field state root distribution in soil.

  9. Plant root-microbe communication in shaping root microbiomes.

    Science.gov (United States)

    Lareen, Andrew; Burton, Frances; Schäfer, Patrick

    2016-04-01

    A growing body of research is highlighting the impacts root-associated microbial communities can have on plant health and development. These impacts can include changes in yield quantity and quality, timing of key developmental stages and tolerance of biotic and abiotic stresses. With such a range of effects it is clear that understanding the factors that contribute to a plant-beneficial root microbiome may prove advantageous. Increasing demands for food by a growing human population increases the importance and urgency of understanding how microbiomes may be exploited to increase crop yields and reduce losses caused by disease. In addition, climate change effects may require novel approaches to overcoming abiotic stresses such as drought and salinity as well as new emerging diseases. This review discusses current knowledge on the formation and maintenance of root-associated microbial communities and plant-microbe interactions with a particular emphasis on the effect of microbe-microbe interactions on the shape of microbial communities at the root surface. Further, we discuss the potential for root microbiome modification to benefit agriculture and food production.

  10. Systems approaches to study root architecture dynamics

    Directory of Open Access Journals (Sweden)

    Candela eCuesta

    2013-12-01

    Full Text Available The plant root system is essential for providing anchorage to the soil, supplying minerals and water, and synthesizing metabolites. It is a dynamic organ modulated by external cues such as environmental signals, water and nutrients availability, salinity and others. Lateral roots are initiated from the primary root post-embryonically, after which they progress through discrete developmental stages which can be independently controlled, providing a high level of plasticity during root system formation.Within this review, main contributions are presented, from the classical forward genetic screens to the more recent high-throughput approaches, combined with computer model predictions, dissecting how lateral roots and thereby root system architecture is established and developed.

  11. Nodulins in root nodule development.

    NARCIS (Netherlands)

    Nap, J.P.H.

    1988-01-01

    In de bodem zijn Rhizobium bacteriën in staat de wortels van vlinderbloemige planten (erwt, boon, klaver) te infecteren en aan te zetten tot de vorming van knolletjes. In die wortelknolletjes zijn de bacteriën in staat om stikstof uit de lucht te binden en om te zetten in ammonia. Met de ammonia kan

  12. [Flexible root posts].

    Science.gov (United States)

    Vadachkoriia, N R; Mandzhavidze, N A; Gumberidze, N Sh

    2009-02-01

    The article discusses the current state of restoration techniques of root canal treatment. Nowadays, technical progress allows manufacturers to develop flexible fiberglass posts, aspiring not only to an excellent aesthetics and mechanical properties (first of all, in comparison with metal and cast posts), but also to maintenance of their radio density and a wide range of forms. Growth of fiberglass posts popularity testifies to their clinical efficiency that also is confirmed by results of long-term researches. Introduction of fiberglass posts in a dental practice has rendered huge influence on restoration techniques of root canal treatment. Convincing factors of fiberglass posts superiority provide restoration the appearance similar with the natural dentition; possess close to dentine elasticity; creation of monolithic structure with hard tooth tissues and composite cement, posts, in case of need, can be easily adjusted on length, adhesive linkage of posts gives them additional stability. Modern researches have confirmed that only elastic, namely carbon fiber and the fiberglass posts made of modern technologies possess similar physical properties, as tooth structure. They can create reliable biomimetic design; solve a complex of aesthetic and functional restoration problems.

  13. IL-4 gene expression in adventitial layer (fibrous layer) of hepatic ovine and bovine hydatid cysts.

    Science.gov (United States)

    Dorosti, Zahra; Tolouei, Sepideh; Khanahmad, Hossein; Jafari, Rasool; Jafaee, Fereshteh; Sharafi, Seyedeh Marayam; Darani, Hossein Yousofi

    2016-09-01

    Cystic Echinococcosis is a parasitic disease with cosmopolitan distribution caused by the tape worm Echinococcus granulosus. Fibrous layer is developed around the cyst as a host immune response reaction. The aim of this study was to evaluate the rate of IL-4 gene expression in fibrous layer of bovine and ovine hepatic hydatid cysts using quantitative technique of Real-Time PCR. In this descriptive study the samples of hydatid cyst fibrous layer were taken from 6 bovine and 6 ovine hepatic hydatid cysts. Samples of normal liver tissue close to the cyst were also taken as controls. Total RNA from each sample was extracted and then converted to cDNA. Afterward, the rate of IL-4 gene expression for each sample was evaluated using real-time PCR technique. Data were analyzed by REST software (version 2.0.13, 2009). In sheep the rate of IL-4 gene expression in the fibrous layer of hepatic hydatid cysts was 1.98 times more than the rate of IL4 gene expression in control samples, but the difference was not significant (P = 0.561). In cattle the rate of IL-4 gene expression in the fibrous layer of hepatic hydatid cysts was 9.84 times more than that of control samples which was statistically significant (P layer of bovine hydatid cyst, it can be concluded that this interleukin may play an important role in host parasite relationship.

  14. The Roots of School Leadership.

    Science.gov (United States)

    Sergiovanni, Thomas J.

    1994-01-01

    The Pyramid, Railroad, and High Performance theories of leadership are inappropriate for school settings. At root, school leadership is about connecting people morally to each other and to their work. The work of leadership involves developing shared purposes, beliefs, values, and conceptions associated with teaching and learning,…

  15. 根表铁膜对2种景观湿地植物根系发育及活力的影响%Effect of Iron Plaque on Root Growth and Activity of Two Wetland Plants

    Institute of Scientific and Technical Information of China (English)

    钟顺清

    2015-01-01

    Root activity is an important indicator of plant response to environmental conditions.High iron content (Fe-plaques)frequently form on roots of wetland plants,reflecting the adaptation of wetland plants to submersion, facilitates nutrient uptake and prevents uptake of phytotoxins.In this study,root activity and the growth of adventi-tious roots of Typha latifolia and Iris pseudacorus in solution culture experiments were determined to investigate the response of wetland plant roots to iron plaque induced on the root surface.Typha latifolia and Iris pseudacorus (each 60 plants)were cultivated in Hoagland nutrient solution for one week.After adventitious roots of Typha lati-folia and Iris pseudacorus emerged,the existing root was removed and the plants were cultivated in the Hoagland so-lution for an additional three weeks at a pH of 5 .5 .Thirty-five plants with similar shoot height and root length were transferred to seven plastic buckets with a solution pH of 5.0 and different Fe2+(FeSO4·7H2O)concentrations (0,10,20,60,100,150,200 mg/L)to induce iron plague formation.The buckets were covered with black po-lyethylene bags and filled with N2 gas.After five days,two plants were removed from solution to determine root ac-tivity.One week later,the fresh weight and activity of the adventitious roots of both species in all treatment groups were measured.Adventitious root growth of Typha latifolia was inhibited by Fe2+concentrations of less than 100 mg/L,but was promoted at concentrations over 100 mg/L.At higher Fe2+concentrations,the root activity of Typha latifolia decreased and there was a large difference [9.70 μg/(g·h)]between maximum and minimum values.However,the influence of Fe plague on the adventitious root growth of Iris pseudacorus was not significant in all treatments,and the root activity of Iris pseudacorus ranged from 2.36 μg/(g·h)to 5.48 μg/(g·h)with little variation among treatments.There was a significant negative relationship between the root

  16. Malformations of the tooth root in humans

    Directory of Open Access Journals (Sweden)

    Hans Ulrich eLuder

    2015-10-01

    Full Text Available The most common root malformations in humans arise from either developmental disorders of the root alone or disorders of radicular development as part of a general tooth dysplasia. The aim of this review is to relate the characteristics of these root malformations to potentially disrupted processes involved in radicular morphogenesis. Radicular morphogenesis proceeds under the control of Hertwig's epithelial root sheath (HERS which determines the number, length, and shape of the root, induces the formation of radicular dentin, and participates in the development of root cementum. Formation of HERS at the transition from crown to root development appears to be very insensitive to adverse effects, with the result that rootless teeth are extremely rare. In contrast, shortened roots as a consequence of impaired or prematurely halted apical growth of HERS constitute the most prevalent radicular dysplasia which occurs due to trauma and unknown reasons as well as in association with dentin disorders. While odontoblast differentiation inevitably stops when growth of HERS is arrested, it seems to be unaffected even in cases of severe dentin dysplasias such as regional odontodysplasia and dentin dysplasia type I. As a result radicular dentin formation is at least initiated and progresses for a limited time. The only condition affecting cementogenesis is hypophosphatasia which disrupts the formation of acellular cementum through an inhibition of mineralization. A process particularly susceptible to adverse effects appears to be the formation of the furcation in multirooted teeth. Impairment or disruption of this process entails taurodontism, single-rooted posterior teeth, and misshapen furcations. Thus even though many characteristics of human root malformations can be related to disorders of specific processes involved in radicular morphogenesis, precise inferences as to the pathogenesis of these dysplasias are hampered by the still limited knowledge on

  17. PHIV-RootCell: a supervised image analysis tool for rice root anatomical parameter quantification

    Directory of Open Access Journals (Sweden)

    Marc eLartaud

    2015-01-01

    Full Text Available We developed the PHIV-RootCell software to quantify anatomical traits of rice roots transverse section images. Combined with an efficient root sample processing method for image acquisition, this program permits supervised measurements of areas (those of whole root section, stele, cortex and central metaxylem vessels, number of cell layers and number of cells per cell layer. The PHIV-RootCell toolset runs under ImageJ, an independent operating system that has a license-free status. To demonstrate the usefulness of PHIV-RootCell, we conducted a genetic diversity study and an analysis of salt-stress responses of root anatomical parameters in rice (Oryza sativa L.. Using 16 cultivars, we showed that we could discriminate between some of the varieties even at the 6 day-old stage, and that tropical japonica varieties had larger root sections due to an increase in cell number. We observed, as described previously, that root sections become enlarged under salt stress. However, our results show an increase in cell number in ground tissues (endodermis and cortex but a decrease in external (peripheral tissues (sclerenchyma, exodermis and epidermis. Thus, the PHIV-RootCell program is a user-friendly tool that will be helpful for future genetic and physiological studies that investigate root anatomical trait variations.

  18. Mycorrhiza alters the profile of root hairs in trifoliate orange.

    Science.gov (United States)

    Wu, Qiang-Sheng; Liu, Chun-Yan; Zhang, De-Jian; Zou, Ying-Ning; He, Xin-Hua; Wu, Qing-Hua

    2016-04-01

    Root hairs and arbuscular mycorrhiza (AM) coexist in root systems for nutrient and water absorption, but the relation between AM and root hairs is poorly known. A pot study was performed to evaluate the effects of four different AM fungi (AMF), namely, Claroideoglomus etunicatum, Diversispora versiformis, Funneliformis mosseae, and Rhizophagus intraradices on root hair development in trifoliate orange (Poncirus trifoliata) seedlings grown in sand. Mycorrhizal seedlings showed significantly higher root hair density than non-mycorrhizal seedlings, irrespective of AMF species. AMF inoculation generally significantly decreased root hair length in the first- and second-order lateral roots but increased it in the third- and fourth-order lateral roots. AMF colonization induced diverse responses in root hair diameter of different order lateral roots. Considerably greater concentrations of phosphorus (P), nitric oxide (NO), glucose, sucrose, indole-3-acetic acid (IAA), and methyl jasmonate (MeJA) were found in roots of AM seedlings than in non-AM seedlings. Levels of P, NO, carbohydrates, IAA, and MeJA in roots were correlated with AM formation and root hair development. These results suggest that AMF could alter the profile of root hairs in trifoliate orange through modulation of physiological activities. F. mosseae, which had the greatest positive effects, could represent an efficient AM fungus for increasing fruit yields or decreasing fertilizer inputs in citrus production.

  19. Effect of lead on root growth.

    Science.gov (United States)

    Fahr, Mouna; Laplaze, Laurent; Bendaou, Najib; Hocher, Valerie; Mzibri, Mohamed El; Bogusz, Didier; Smouni, Abdelaziz

    2013-01-01

    Lead (Pb) is one of the most widespread heavy metal contaminant in soils. It is highly toxic to living organisms. Pb has no biological function but can cause morphological, physiological, and biochemical dysfunctions in plants. Plants have developed a wide range of tolerance mechanisms that are activated in response to Pb exposure. Pb affects plants primarily through their root systems. Plant roots rapidly respond either (i) by the synthesis and deposition of callose, creating a barrier that stops Pb entering (ii) through the uptake of large amounts of Pb and its sequestration in the vacuole accompanied by changes in root growth and branching pattern or (iii) by its translocation to the aboveground parts of plant in the case of hyperaccumulators plants. Here we review the interactions of roots with the presence of Pb in the rhizosphere and the effect of Pb on the physiological and biochemical mechanisms of root development.

  20. Conjoined lumbosacral nerve roots

    Directory of Open Access Journals (Sweden)

    Atila Yılmaz

    2012-03-01

    Full Text Available Lumbosacral nerve root anomalies are a rare group ofcongenital anatomical anomalies. Various types of anomaliesof the lumbosacral nerve roots have been documentedin the available international literature. Ttheseanomalies may consist of a bifid, conjoined structure, ofa transverse course or of a characteristic anastomizedappearance. Firstly described as an incidental findingduring autopsies or surgical procedures performed forlumbar disk herniations and often asymptomatic, lumbosacralnerve root anomalies have been more frequentlydescribed in the last years due to the advances made inradiological diagnosis.

  1. Induction of Adventitious Buds from Calli of Ardisia Crenata Sims%富贵籽愈伤组织诱导不定芽的研究

    Institute of Scientific and Technical Information of China (English)

    丁力; 孔祥海; 邱丰艳; 吴晓琛; 王珠平; 吕小华

    2012-01-01

    为了科学合理地开发利用具有观赏与药用价值的富贵籽,采用组织培养技术,考察不同植物激素组合的培养基对种子胚和茎段愈伤组织诱导以及愈伤组织诱导不定芽的影响。结果显示:(1)MS+2,4-D 1.0+BA 0.05的培养基配方较适合用于富贵籽种子胚诱导形成愈伤组织;(2)MS+NAA 1.5 0+BA 2.00的组合配方能较好的诱导富贵籽茎段产生愈伤组织;(3)MS+6-BA 0.6+NAA 0.05的培养基较适合于诱导富贵籽的原代愈伤组织分化产生不定芽。%In order to exploit and utilize the plant resource of Ardisia crenata(an ornamental and medicinal plant) scientifically and rationally,the research of adventitious buds induction from callus was carried out.According to the experience of the early research,single-factor experimental design,which used different auxin types and concentrations,was adopted for callus induction from seed embryo and stem of Ardisia crenata.The experiment,which selected the combination of NAA 0.05 m·L-1(the same as below) with different concentrations of BA,was conducted for adventitious buds induction from different subculture callus of Ardisia crenata.The results showed(1) The medium formula of MS + 2,4-D 1.0 + BA 0.05 was suitable for callus induction from seed embryo;(2) The medium formula of MS + NAA 1.5 0 + BA 2.00 was suitable for callus induction from stem;(3) The medium formula of MS + 6-BA 0.6 + NAA 0.05 was suitable for adventitious buds from primary callus.

  2. Economic strategies of plant absorptive roots vary with root diameter

    Science.gov (United States)

    Kong, D. L.; Wang, J. J.; Kardol, P.; Wu, H. F.; Zeng, H.; Deng, X. B.; Deng, Y.

    2016-01-01

    Plant roots typically vary along a dominant ecological axis, the root economics spectrum, depicting a tradeoff between resource acquisition and conservation. For absorptive roots, which are mainly responsible for resource acquisition, we hypothesized that root economic strategies differ with increasing root diameter. To test this hypothesis, we used seven plant species (a fern, a conifer, and five angiosperms from south China) for which we separated absorptive roots into two categories: thin roots (thickness of root cortex plus epidermis perspective on our understanding of the root economics spectrum.

  3. A digital photography and analysis system for estimation of root and shoot development in rice weed suppression studies in the field

    Science.gov (United States)

    Rice germplasm with an inherent ability to suppress weeds can potentially improve the economics and sustainability of weed control in rice. We devised a simple, rapid, and inexpensive digital imaging system to quantify several shoot and root growth characteristics in field-grown rice plants that ha...

  4. Revealing the importance of meristems and roots for the development of hypersensitive responses and full foliar resistance to Phytophthora infestans in the resistant potato cultivar Sarpo Mira

    DEFF Research Database (Denmark)

    Orlowska, Elzbieta Zofia; Basile, Alessio; Kandzia, Izabela

    2012-01-01

    The defence responses of potato against Phytophthora infestans were studied using the highly resistant Sarpo Mira cultivar. The effects of plant integrity, meristems, and roots on the hypersensitive response (HR), plant resistance, and the regulation of PR genes were analysed. Sarpo Mira shoots a...

  5. The development of an efficient cultivar-independent plant regeneration system from callus derived from both apical and non-apical root segments of garlic (Allium sativum L.)

    NARCIS (Netherlands)

    Zheng, S.J.; Henken, G.; Krens, F.A.; Kik, C.

    2003-01-01

    Callus induction and later plant regeneration were studied in four widely grown garlic (Allium sativum L.) cultivars from Europe. Root segments from in vitro plantlets were used as starting material. In addition to cultivar effects, the effects of auxin and cytokinin levels and the position of the s

  6. Sampling techniques and detection methods for developing risk assessments for root-knot nematode (Meloidogyne incognita) on lima bean (Phaseolus lunatus) in the Mid-Atlantic region

    Science.gov (United States)

    Lima bean, Phaseolus lunatus, is a cornerstone crop in the Mid-Atlantic region and Meloidogyne incognita, the southern root knot nematode (RKN), causes significant yield loss. The RKN has become more pervasive as toxic nematicides have been removed from the market, and risk evaluation research is ne...

  7. Studies on the spatial and time development of soil- and root-chemical stress parameters and on the effects of said parameters on fine root development in acid soil forest ecosystems of the Hils. Untersuchungen zur raumzeitlichen Entwicklung boden- und wurzelchemischer Stressparameter und deren Einfluss auf die Feinwurzelentwicklung in bodensauren Waldgesellschaften des Hils

    Energy Technology Data Exchange (ETDEWEB)

    Raben, G.H.

    1988-01-01

    The soil chemistry parameters of different forest ecosystems were investigated. Increased aluminium concentrations were found in acid soils. The depth distribution of the living and dead fine root mass was investigated, and root-damaging Ca/Al ratios were marked out.

  8. Avaliação da porosidade e placa férrica de raízes de arroz cultivado em hipoxia Evaluation of porosity and iron plaque on rice roots grown under hypoxia

    Directory of Open Access Journals (Sweden)

    Marquel Jonas Holzschuh

    2010-10-01

    servir como estimativa da formação de aerênquima no arroz. O método de obtenção de raízes foi eficiente em promover a eliminação de O2 do saco de vinil para estudar a formação do aerênquima.The high oxygen diffusion in different materials makes the establishment and maintenance of oxygen-free environments difficult. The techniques used to obtain oxygen-free environments are little efficient and not representative of flooded soil conditions. The purpose of this study was to develop a method for obtaining roots in a hypoxic environment to evaluate iron plaque and aerenchyma formation in rice plants. A hypoxic condition similar to that of flooded soils was created in 50 L tanks, based on the oxygen diffusion capacity through vinyl plastic in contact with flooded soil. Each tank was filled with soil (Gley soil, five vinyl bags and then flooded. Rice plants of the genotypes IRGA 423 and IRGA 424 grown in the field were collected, the roots cut at the stem, washed and 1/3 of the leaves removed. Each bag was filled with 12 plants of each genotype and nutrient solution. After seven days, the new adventitious roots were used to determine the iron plaque and aerenchyma formation in the segments 0-2, 2-4 and 4-6 cm from the root tips. The roots were exposed the solution of a flooded soil for 4 hours. The iron plaque was determined in the root segments after iron extraction with HCl 0.5 mol L-1. Porosity was determined in vacuum cycles applied with a syringe. The weight difference before and after vacuum treatment and water entrance was assumed as estimate of the magnitude of the aerenchyma of the roots. The method was tested with the production of new adventitious roots in vinyl bags under aerated and hypoxic conditions. Root porosity was higher in the hypoxic than in the aerated environment. Porosity was higher near plant base and as porosity increased, iron increased near the root surface, indicating the iron plaque as a parameter to estimate aerenchyma formation in

  9. Root selection methods in flood analysis

    Directory of Open Access Journals (Sweden)

    B. Parmentier

    2003-01-01

    Full Text Available In the 1970s, de Laine developed a root-matching procedure for estimating unit hydrograph ordinates from estimates of the fast component of the total runoff from multiple storms. Later, Turner produced a root selection method which required only data from one storm event and was based on recognising a pattern typical of unit hydrograph roots. Both methods required direct runoff data, i.e. prior separation of the slow response. This paper introduces a further refinement, called root separation, which allows the estimation of both the unit hydrograph ordinates and the effective precipitation from the full discharge hydrograph. It is based on recognising and separating the quicker component of the response from the much slower components due to interflow and/or baseflow. The method analyses the z-transform roots of carefully selected segments of the full hydrograph. The root patterns of these separate segments tend to be dominated by either the fast response or the slow response. This paper shows how their respective time-scales can be distinguished with an accuracy sufficient for practical purposes. As an illustration, theoretical equations are derived for a conceptual rainfall-runoff system with the input split between fast and slow reservoirs in parallel. These are solved analytically to identify the reservoir constants and the input splitting parameter. The proposed method, called 'root separation', avoids the subjective selection of rainfall roots in the Turner method as well as the subjective matching of roots in the original de Laine method. Keywords: unit hydrograph,identification methods, z-transform, polynomial roots, root separation, fast andslow response, Nash cascade

  10. Root-soil relationships and terroir

    Science.gov (United States)

    Tomasi, Diego

    2015-04-01

    Soil features, along with climate, are among the most important determinants of a succesful grape production in a certain area. Most of the studies, so far, investigated the above-ground vine response to differente edaphic and climate condition, but it is clearly not sufficient to explain the vine whole behaviour. In fact, roots represent an important part of the terroir system (soil-plant-atmosphere-man), and their study can provide better comprehension of vine responses to different environments. The root density and distribution, the ability of deep-rooting and regenerating new roots are good indicators of root well-being, and represents the basis for an efficient physiological activity of the root system. Root deepening and distribution are strongly dependent and sensitive on soil type and soil properties, while root density is affected mostly by canopy size, rootstock and water availability. According to root well-being, soil management strategies should alleviate soil impediments, improving aeration and microbial activity. Moreover, agronomic practices can impact root system performance and influence the above-ground growth. It is well known, for example, that the root system size is largely diminished by high planting densities. Close vine spacings stimulate a more effective utilization of the available soil, water and nutrients, but if the competition for available soil becomes too high, it can repress vine growth, and compromise vineyard longevity, productivity and reaction to growing season weather. Development of resilient rootstocks, more efficient in terms of water and nutrient uptake and capable of dealing with climate and soil extremes (drought, high salinity) are primary goals fore future research. The use of these rootstocks will benefit a more sustainable use of the soil resources and the preservation and valorisation of the terroir.

  11. Nemesia root hair response to paper pulp substrate for micropropagation.

    Science.gov (United States)

    Labrousse, Pascal; Delmail, David; Decou, Raphaël; Carlué, Michel; Lhernould, Sabine; Krausz, Pierre

    2012-01-01

    Agar substrates for in vitro culture are well adapted to plant micropropagation, but not to plant rooting and acclimatization. Conversely, paper-pulp-based substrates appear as potentially well adapted for in vitro culture and functional root production. To reinforce this hypothesis, this study compares in vitro development of nemesia on several substrates. Strong differences between nemesia roots growing in agar or in paper-pulp substrates were evidenced through scanning electron microscopy. Roots developed in agar have shorter hairs, larger rhizodermal cells, and less organized root caps than those growing on paper pulp. In conclusion, it should be noted that in this study, in vitro microporous substrates such as paper pulp lead to the production of similar root hairs to those found in greenhouse peat substrates. Consequently, if agar could be used for micropropagation, rooting, and plant acclimatization, enhancement could be achieved if rooting stage was performed on micro-porous substrates such as paper pulp.

  12. Formation and separation of root border cells.

    Science.gov (United States)

    Driouich, Azeddine; Durand, Caroline; Vicré-Gibouin, Maïté

    2007-01-01

    Plant roots release a large number of border cells into the rhizosphere, which are believed to play a key role in root development and health. The formation and loss of these cells from the root cap region is a developmentally regulated process that is also controlled by phytohormones and environmental factors. The separation of border cells involves the complete dissociation of individual cells from each other and from root tissue. This process requires the activity of cell wall-degrading enzymes that solubilize the cell wall connections between cells. We present and discuss the solubilization process with an emphasis on pectin-degrading enzymes as well as the recently discovered root border-like cells of Arabidopsis thaliana.

  13. Phosphate-dependent root system architecture responses to salt stress

    NARCIS (Netherlands)

    Kawa, D.; Julkowska, M.M.; Montero Sommerfeld, H.; ter Horst, A.; Haring, M.A.; Testerink, C.

    2016-01-01

    Nutrient availability and salinity of the soil affect growth and development of plant roots. Here, we describe how phosphate availability affects root system architecture (RSA) of Arabidopsis and how phosphate levels modulate responses of the root to salt stress. Phosphate (Pi) starvation reduced ma

  14. 禾本科植物根系发育的分子机制研究进展%Research Advances on the Molecular Mechanisms of Root Development in Gramineous Plants

    Institute of Scientific and Technical Information of China (English)

    任永哲; 徐艳花; 张庆琛; 梁峰

    2011-01-01

    植物根系的主要功能是从土壤中吸收养分和水分,并起到固定植株的功能.因此根系对于植物完成生命周期是至关重要的.以往的研究多集中在对模式植物拟南芥的根系上,近年来,人们开始对禾本科植物根系发育的分子机制开展研究并取得了一定的进展,一些科学家开始利用QTL定位的方法对调控植物根系性状的基因进行定位,对根系表型鉴定的方法也进行了很多改良.现有的研究结果表明,禾本科植物根系发育的分子机制与拟南芥既有相似之处,又存在一定的差异.对近几年来禾本科植物根系发育的分子机制方面取得的研究结果进行了综述,并对根系育种的重要性及其困难进行了探讨.%Plant roots are required for the acquisition of water and nutrients, and fixition of plant. The proper establishment of root system architecture is of vital importance to fulfill its functional requirements, particularly in agronomically important crops such as cereals, which account for 70% of food production worldwide. In recent years, studies on the molecular mechanisms regulating root development have also been initiated in monocot cereals which have been well studied in Arabidopsis in the past ten years. The achievements of root development in cereals were reviewed in this paper. The application of quantitative trait locus mapping in studying root development and the application of root trait information in breeding were also discussed.

  15. Chromatic roots and hamiltonian paths

    DEFF Research Database (Denmark)

    Thomassen, Carsten

    2000-01-01

    We present a new connection between colorings and hamiltonian paths: If the chromatic polynomial of a graph has a noninteger root less than or equal to t(n) = 2/3 + 1/3 (3)root (26 + 6 root (33)) + 1/3 (3)root (26 - 6 root (33)) = 1.29559.... then the graph has no hamiltonian path. This result...

  16. Pullout tests of root analogs and natural root bundles in soil: Experiments and modeling

    Science.gov (United States)

    Schwarz, M.; Cohen, D.; Or, D.

    2011-06-01

    Root-soil mechanical interactions are key to soil stability on steep hillslopes. Motivated by new advances and applications of the Root Bundle Model (RBM), we conducted a series of experiments in the laboratory and in the field to study the mechanical response of pulled roots. We systematically quantified the influence of different factors such as root geometry and configuration, soil type, and soil water content considering individual roots and root bundles. We developed a novel pullout apparatus for strain-controlled field and laboratory tests of up to 13 parallel roots measured individually and as a bundle. Results highlight the importance of root tortuosity and root branching points for prediction of individual root pullout behavior. Results also confirm the critical role of root diameter distribution for realistic prediction of global pullout behavior of a root bundle. Friction between root and soil matrix varied with soil type and water content and affected the force-displacement behavior. Friction in sand varied from 1 to 17 kPa, with low values obtained in wet sand at a confining pressure of 2 kPa and high values obtained in dry sand with 4.5 kPa confining pressure. In a silty soil matrix, friction ranged between 3 kPa under wet and low confining pressure (2 kPa) and 6 kPa in dry and higher confining pressure (4.5 kPa). Displacement at maximum pullout force increased with increasing root diameter and with tortuosity. Laboratory experiments were used to calibrate the RBM that was later validated using six field measurements with natural root bundles of Norway spruce (Picea abies L.). These tests demonstrate the progressive nature of root bundle failure under strain-controlled pullout force and provide new insights regarding force-displacement behavior of root reinforcement, highlighting the importance of considering displacement in slope stability models. Results show that the magnitude of maximum root pullout forces (1-5 kPa) are important for slope

  17. ROOT ALLOMETRY OF TWO SUBTROPICAL PLANT COMMUNITIES OF NORTHEASTERN MEXICO

    OpenAIRE

    Eduardo de los Ríos-Carrasco; José de Jesús Návar-Cháidez

    2010-01-01

    This research work aimed at the study of the root allometry in sub-tropical Tamaulipan thornscrub and pine forest communities of Nuevo Leon, Mexico. By excavating each individual root of each of 20 trees per plant community, we developed root allometric equations for biomass, volume, total length and diameter. Covariance analysis, ancova, was employed to determine the statistical difference of these variables between plant communities. Results indicate that pine plant trees have larger root v...

  18. ROOT I/O in Javascript - Reading ROOT files in a browser

    CERN Document Server

    CERN. Geneva

    2012-01-01

    A JavaScript version of the ROOT I/O subsystem is being developed, in order to be able to browse (inspect) ROOT files in a platform independent way. This allows the content of ROOT files to be displayed in most web browsers, without having to install ROOT or any other software on the server or on the client. This gives a direct access to ROOT files from new (e.g. portable) devices in a light way. It will be possible to display simple graphical objects such as histograms and graphs (TH1, TH2, TH3, TProfile, TGraph, ...). The rendering will first be done with an external JavaScript graphic library, before investigating a way to produce graphics closer to what ROOT supports on other platforms (X11, Windows).

  19. Cytological and ultrastructural studies on root tissues

    Science.gov (United States)

    Slocum, R. D.; Gaynor, J. J.; Galston, A. W.

    1984-01-01

    The anatomy and fine structure of roots from oat and mung bean seedlings, grown under microgravity conditions for 8 days aboard the Space Shuttle, was examined and compared to that of roots from ground control plants grown under similar conditions. Roots from both sets of oat seedlings exhibited characteristic monocotyledonous tissue organization and normal ultrastructural features, except for cortex cell mitochondria, which exhibited a 'swollen' morphology. Various stages of cell division were observed in the meristematic tissues of oat roots. Ground control and flight-grown mung bean roots also showed normal tissue organization, but root cap cells in the flight-grown roots were collapsed and degraded in appearance, especially at the cap periphery. At the ultrastructural level, these cells exhibited a loss of organelle integrity and a highly-condensed cytoplasm. This latter observation perhaps suggests a differing tissue sensitivity for the two species to growth conditions employed in space flight. The basis for abnormal root cap cell development is not understood, but the loss of these putative gravity-sensing cells holds potential significance for long term plant growth orientation during space flight.

  20. Sulfur nutrient availability regulates root elongation by affecting root indole-3-acetic acid levels and the stem cell niche

    Institute of Scientific and Technical Information of China (English)

    Qing Zhao; Yu Wu; Lei Gao; Jun Ma; Chuan-You Li; Cheng-Bin Xiang

    2014-01-01

    Sulfur is an essential macronutrient for plants with numerous biological functions. However, the influence of sulfur nutrient availability on the regulation of root development remains largely unknown. Here, we report the response of Arabidopsis thaliana L. root development and growth to different levels of sulfate, demonstrating that low sulfate levels promote the primary root elongation. By using various reporter lines, we examined in vivo IAA level and distribution, cel division, and root meristem in response to different sulfate levels. Meanwhile the dynamic changes of in vivo cysteine, glutathione, and IAA levels were measured. Root cysteine, glutathione, and IAA levels are positively correlated with external sulfate levels in the physiological range, which eventual y affect root system architecture. Low sulfate levels also downregulate the genes involved in auxin biosynthesis and transport, and elevate the accumulation of PLT1 and PLT2. This study suggests that sulfate level affects the primary root elongation by regulating the endogenous auxin level and root stem cel niche maintenance.

  1. Avaliação do enraizamento, desenvolvimento de raízes e parte aérea de porta-enxertos de videira em condições de campo Evaluation of rooting, development of roots and shoot biomass from rootstock of grapevine, in field conditions

    Directory of Open Access Journals (Sweden)

    Marco Antonio Tecchio

    2007-12-01

    Full Text Available Objetivou-se neste trabalho avaliar o enraizamento, a brotação e o desenvolvimento de raízes de diferentes porta-enxertos de videira em condições de campo. Estacas lenhosas dos porta-enxertos '420 A', 'Golia', '5C', '8B', 'RR101-14', 'SO4', '99R', 'Kober 5BB', 'IAC 766', 'IAC 572', 'IAC 571-6', 'Ripária do Traviú' e 'Rupestris du Lot' foram colocadas em canteiro de terra, sem tratamento prévio. O delineamento foi em blocos ao acaso, com cinco repetições e vinte estacas por parcela, com as estacas dispostas em espaçamento de 12 x 5cm. As estacas foram colocadas para enraizar no início de julho e removidas no final de setembro para as avaliações. A porcentagem de estacas enraizadas variou de 79% para 'Ripária do Traviú' a 99% para o 'RR101-14'. Quanto à brotação, o 'Ripária do Traviú' apresentou 47%, 'IAC 571-6', 'IAC 572', '420 A', 'Rupestris du Lot', 'Kober', 'IAC 766', '8B', '5C', apresentaram de 76 a 89% e 'Golia', 'SO4', '99R' e 'RR 101-14' mais de 90%. 'IAC 572' e 'IAC 571-6' apresentaram o menor número de raízes por estaca, no entanto, foram as que apresentaram raízes mais desenvolvidas, seguidas pelo '5C' e 'Rupestris du Lot'. 'Kober 5BB' e 'Ripária do Traviú' apresentaram as raízes menos desenvolvidas. As demais variedades apresentaram valores intermediários. Concluiu-se que, entre todos os porta-enxertos, o 'Ripária do Traviú' apresentou os menores índices de enraizamento e brotação das estacas, nas condições de campo.The goals of this investigation was to evaluate the rooting, budding and development of roots from different rootstock of grapevine, in field conditions. Ligneous cutting of rootstock '420 A', 'Golia', '5C', '8B', 'RR101-14', 'SO4', '99R', 'Kober 5BB', 'IAC 766', 'IAC 572', 'IAC 571-6', 'Ripária do Traviú' and 'Rupestris du Lot' were planted in soil, without previous preparation. The experimental design was done in randomized blocks, with five repetitions and twenty cutting per plot

  2. Root type matters: measurements of water uptake by seminal, crown and lateral roots of maize

    Science.gov (United States)

    Ahmed, Mutez Ali; Zarebanadkouki, Mohsen; Kaestner, Anders; Carminati, Andrea

    2016-04-01

    Roots play a key role in water acquisition and are a significant component of plant adaptation to different environmental conditions. Although maize (Zea mays L.) is one of the most important crops worldwide, there is limited information on the function of different root segments and types in extracting water from soils. Aim of this study was to investigate the location of root water uptake in mature maize. We used neutron radiography to image the spatial distribution of maize roots and trace the transport of injected deuterated water (D2O) in soil and roots. Maize plants were grown in aluminum containers filled with a sandy soil that was kept homogeneously wet throughout the experiment. When the plants were five weeks-old, we injected D2O into selected soil regions. The transport of D2O was simulated using a diffusion-convection numerical model. By fitting the observed D2O transport we quantified the diffusion coefficient and the water uptake of the different root segments. The model was initially developed and tested with two weeks-old maize (Ahmed et. al. 2015), for which we found that water was mainly taken up by lateral roots and the water uptake of the seminal roots was negligible. Here, we used this method to measure root water uptake in a mature maize root system. The root architecture of five weeks-old maize consisted of primary and seminal roots with long laterals and crown (nodal) roots that emerged from the above ground part of the plant two weeks after planting. The crown roots were thicker than the seminal roots and had fewer and shorter laterals. Surprisingly, we found that the water was mainly taken up by the crown roots and their laterals, while the lateral roots of seminal roots, which were the main location of water uptake of younger plants, stopped to take up water. Interestingly, we also found that in contrast to the seminal roots, the crown roots were able to take up water also from their distal segments. We conclude that for the two weeks

  3. Final Report Grant No. DE-FG02-98ER20307 Lipopolysaccharide Structures and Genes Required for Root Nodule Development August 1, 2004 to July 31, 2008

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    Noel, K. Dale [Marquette Univ., Milwaukee,WI (United States)

    2008-12-07

    This project dealt with the plant-bacterial symbiosis that gives rise to root nodules on leguminous plants in which the bacteria carry out nitrogen fixation. Nitrogen fixation, like carbon dioxide fixation, is essential for life on planet earth, and this symbiosis is estimated to account for half of all nitrogen fixed on land. Aside from being important for the sustenance of global life, this ability allows legumes to grow without nitrogen fertilizers. Basic studies such as this project are aimed at understanding the symbiosis well enough that eventually it can be engineered into important crop species so that they no longer depend on nitrogen fertilizer for growth. The production and distribution of excessive fertilizer needed for optimal crop yields is responsible for a significant portion of the energy costs in agriculture. The specific aims of this work were to further the understanding of a bacterial factor that is essential for the symbiotic infection process. This factor is a bacterial surface molecule, lipopolysaccharide O antigen. In this project we showed that, not only the presence, but the specific structure of this molecule is crucial for infection. Although the success of bacterial infections in many pathogenic and mutualistic interactions have been shown to depend on intact O antigen, it has been very rare to establish that specific features of the structure are important. One of the features in this case is the presence of one additional methyl group on one sugar in the O antigen. It is very surprising that such a minor change should have an observable effect. This work sets the stage for biochemical studies of possible plant receptors that may be involved. During the course of this grant period, we developed a method of testing the importance of this bacterial component at stages of nodule development beyond the step that is blocked by null mutation. The method works adequately for this purpose and is being improved. It has implications for testing

  4. X-ray computed tomography uncovers root-root interactions: quantifying spatial relationships between interacting root systems in three dimensions

    Directory of Open Access Journals (Sweden)

    Alexander Martin Paya

    2015-04-01

    Full Text Available Research in the field of plant biology has recently demonstrated that inter- and intra-specific interactions belowground can dramatically alter root growth. Our aim was to answer questions related to the effect of inter- vs. intra-specific interactions on the growth and utilization of undisturbed space by fine roots within three dimensions (3D using micro X-ray computed tomography. To achieve this, Populus tremuloides (quaking aspen and Picea mariana (black spruce seedlings were planted into containers as either solitary individuals, or inter-/intra-specific pairs, allowed to grow for two months, and 3D metrics developed in order to quantify their use of belowground space. In both aspen and spruce, inter-specific root interactions produced a shift in the vertical distribution of the root system volume, and deepened the average position of root tips when compared to intra-specifically growing seedlings. Inter-specific interactions also increased the minimum distance between root tips belonging to the same root system. There was no effect of belowground interactions on the radial distribution of roots, or the directionality of lateral root growth for either species. In conclusion, we found that significant differences were observed more often when comparing controls (solitary individuals and paired seedlings (inter- or intra-specific, than when comparing inter- and intra-specifically growing seedlings. This would indicate that competition between neighboring seedlings was more responsible for shifting fine root growth in both species than was neighbor identity. However, significant inter- vs. intra-specific differences were observed, which further emphasizes the importance of biological interactions in competition studies.

  5. Regeneración de brotes adventicios en hojas de guayaba (Psidium guajava L. cultivadas in vitro Adventitious shoot regeneration from in vitro cultured leaves of guava (Psidium guava L.

    Directory of Open Access Journals (Sweden)

    Trujillo Sánchez Reinaldo

    2004-12-01

    Full Text Available La regeneración de brotes adventicios es una etapa clave para la aplicación de las técnicas de ingeniería gené­tica. El presente trabajo tuvo como objetivo el desarrollo de un procedimiento para la regeneración de brotes por organogénesis a partir de hojas de microesquejes o brotes de guayaba (Psidium guajava L. cultivados in vi­tro. Para ello se estudiaron algunos de los principales factores que afectan la regeneración de brotes, tales como la concentración de reguladores del crecimiento (citoquinina, el estado fisiológico del explante y la he­rida. En todos los experimentos se utilizaron como explantes hojas de vitroplantas de guayaba de la variedad Enana Roja Cubana EEA18-40 de diferentes subcultivos. El mejor resultado se alcanzó con una concentración de 0,75 mg/L de 6-bencilaminopurina como suplemento hormonal del medio MS. Se comprobó que para las hojas provenientes de microesquejes con mayor número de subcultivo y tomadas de la parte inferior de los brotes, el potencial morfogenético disminuye significativamente (p60% y el mayor número de brotes por explante promedio (>3 se alcanzó al realizar varias heridas en forma de punteaduras en el nervio central de las hojas. Este protocolo de regeneración constituye una importante herramienta que puede ser empleada para futuros estudios de transformación genética en esta especie. Palabras clave: cultivo de tejidos, explantes de hoja, reguladores de crecimiento, organogénesis, guayaba.Adventitious regeneration is a key step in the application of genetic engineering to the breeding programs of plants. In this work a method for adventitious shoot regeneration from leaves of micropropagated guava shoots has been developed and some of main factors to affect the shoot regeneration like, concentration of plant growth regulators (citoquinine, physiological state of explants and the wound are studied. Leaves from guava in vitro cultured of variety Cuban Red Dwarf 18-40 was used

  6. Over-expression of mango (Mangifera indica L.) MiARF2 inhibits root and hypocotyl growth of Arabidopsis.

    Science.gov (United States)

    Wu, Bei; Li, Yun-He; Wu, Jian-Yong; Chen, Qi-Zhu; Huang, Xia; Chen, Yun-Feng; Huang, Xue-Lin

    2011-06-01

    An auxin response factor 2 gene, MiARF2, was cloned in our previous study [1] from the cotyledon section of mango (Mangifera indica L. cv. Zihua) during adventitious root formation, which shares an 84% amino acid sequence similarity to Arabidopsis ARF2. This study was to examine the effects of over-expression of the full-length MiARF2 open reading frame on the root and hypocotyl growth in Arabidopsis. Phenotype analysis showed that the T(3) transgenic lines had about 20-30% reduction in the length of hypocotyls and roots of the seedlings in comparison with the wild-type. The transcription levels of ANT and ARGOS genes which play a role in controlling organ size and cell proliferation in the t