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Sample records for adventitious rooting process1

  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. 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.

  4. 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

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

    Science.gov (United States)

    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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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

  11. 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...

  12. 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.

  13. 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.

  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.

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    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. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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

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

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    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.

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

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    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.

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

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    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.

  4. 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.

  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. 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.

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

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    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.

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

    Science.gov (United States)

    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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

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

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    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

  18. 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.

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

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    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.

  20. 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.

  1. 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.

  2. 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.

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

    Science.gov (United States)

    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.

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. 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.

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

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    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.

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

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    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.

  12. 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.

  13. 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.

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

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    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.

  15. 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.

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

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    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.

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

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    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

  18. 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.

  19. 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.

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

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    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.

  1. 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

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

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    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.

  3. 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.

  4. 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

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    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.

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. 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

  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. 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

  17. 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

  18. 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

  19. 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.

  20. [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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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...

  12. 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...

  13. 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.

  14. 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.

  15. 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...

  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. 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.

  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. 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...

  20. 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.

  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. 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%

  3. 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

  4. 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.

  5. [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%.

  6. 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.

  7. 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.

  8. 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).

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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...

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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...

  3. 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...

  4. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Busov, Victor

    2013-03-05

    DR5 as a reporter system to study auxin response in Populus Plant Cell Reports 32:453-463 Auxin responsive promoter DR5 reporter system is functional in Populus to monitor auxin response in tissues including leaves, roots, and stems. We described the behavior of the DR5::GUS reporter system in stably transformed Populus plants. We found several similarities with Arabidopsis, including sensitivity to native and synthetic auxins, rapid induction after treatment in a variety of tissues, and maximal responses in root tissues. There were also several important differences from Arabidopsis, including slower time to maximum response and lower induction amplitude. Young leaves and stem sections below the apex showed much higher DR5 activity than did older leaves and stems undergoing secondary growth. DR5 activity was highest in cortex, suggesting high levels of auxin concentration and/or sensitivity in this tissue. Our study shows that the DR5 reporter system is a sensitive and facile system for monitoring auxin responses and distribution at cellular resolution in poplar. The Populus AINTEGUMENTA LIKE 1 homeotic transcription factor PtAIL1 controls the formation of adventitious root primordia. Plant Physiol. 160: 1996-2006 Adventitious rooting is an essential but sometimes rate-limiting step in the clonal multiplication of elite tree germplasm, because the ability to form roots declines rapidly with age in mature adult plant tissues. In spite of the importance of adventitious rooting, the mechanism behind this developmental process remains poorly understood. We have described the transcriptional profiles that are associated with the developmental stages of adventitious root formation in the model tree poplar (Populus trichocarpa). Transcriptome analyses indicate a highly specific temporal induction of the AINTEGUMENTA LIKE1 (PtAIL1) transcription factor of the AP2 family during adventitious root formation. Transgenic poplar samples that overexpressed PtAIL1 were able to

  6. 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.

  7. 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.

  8. 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

  9. [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.

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

    Directory of Open Access Journals (Sweden)

    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.

  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. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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...

  16. 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

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. [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.

  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. 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.

  7. 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...

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. 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%.

  15. 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).

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Busov, Victor

    2013-03-05

    DR5 as a reporter system to study auxin response in Populus Plant Cell Reports 32:453-463 Auxin responsive promoter DR5 reporter system is functional in Populus to monitor auxin response in tissues including leaves, roots, and stems. We described the behavior of the DR5::GUS reporter system in stably transformed Populus plants. We found several similarities with Arabidopsis, including sensitivity to native and synthetic auxins, rapid induction after treatment in a variety of tissues, and maximal responses in root tissues. There were also several important differences from Arabidopsis, including slower time to maximum response and lower induction amplitude. Young leaves and stem sections below the apex showed much higher DR5 activity than did older leaves and stems undergoing secondary growth. DR5 activity was highest in cortex, suggesting high levels of auxin concentration and/or sensitivity in this tissue. Our study shows that the DR5 reporter system is a sensitive and facile system for monitoring auxin responses and distribution at cellular resolution in poplar. The Populus AINTEGUMENTA LIKE 1 homeotic transcription factor PtAIL1 controls the formation of adventitious root primordia. Plant Physiol. 160: 1996-2006 Adventitious rooting is an essential but sometimes rate-limiting step in the clonal multiplication of elite tree germplasm, because the ability to form roots declines rapidly with age in mature adult plant tissues. In spite of the importance of adventitious rooting, the mechanism behind this developmental process remains poorly understood. We have described the transcriptional profiles that are associated with the developmental stages of adventitious root formation in the model tree poplar (Populus trichocarpa). Transcriptome analyses indicate a highly specific temporal induction of the AINTEGUMENTA LIKE1 (PtAIL1) transcription factor of the AP2 family during adventitious root formation. Transgenic poplar samples that overexpressed PtAIL1 were able to

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. 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).

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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...

  15. 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 transgenic seedlings also decreased. Therefore, the inhibited root and hypocotyl growth in the transgenic seedlings may be associated with the down-regulated transcription of ANT and ARGOS by the over-expression of MiARF2. This study also suggests that although MiARF2 only has a single DNA-binding domain (DBD), it can function as other ARF-like proteins containing complete DBD, middle region (MR) and carboxy-terminal dimerization domain (CTD).

  16. Transgenic modification of gai or rg/1 causes dwarfing and alters gibberellins, root growth, and metabolite profiles in Populus

    Energy Technology Data Exchange (ETDEWEB)

    Tschaplinski, Timothy J [ORNL; Busov, V. [Michigan Technological University; Meilan, R [Purdue University; Pearce, D [University of Lethbridge; Rood, s [University of Lethbridge; Ma, C [Oregon State University; Strauss, S [Oregon State University

    2006-01-01

    In Arabidopsis and other plants, gibberellin (GA)-regulated responses are mediated by proteins including GAI, RGA and RGL1-3 that contain a functional DELLA domain. Through transgenic modification, we found that DELLA-less versions of GAI (gai) and RGL1 (rgl1) in a Populus tree have profound, dominant effects on phenotype, producing pleiotropic changes in morphology and metabolic profiles. Shoots were dwarfed, likely via constitutive repression of GA-induced elongation, whereas root growth was promoted two- to threefold in vitro. Applied GA{sub 3} inhibited adventitious root production in wild-type poplar, but gai/rgl1 poplars were unaffected by the inhibition. The concentrations of bioactive GA{sub 1} and GA{sub 4} in leaves of gai- and rgl1-expressing plants increased 12- to 64-fold, while the C{sub 19} precursors of GA{sub 1} (GA{sub 53}, GA{sub 44} and GA{sub 19}) decreased three- to ninefold, consistent with feedback regulation of GA 20-oxidase in the transgenic plants. The transgenic modifications elicited significant metabolic changes. In roots, metabolic profiling suggested increased respiration as a possible mechanism of the increased root growth. In leaves, we found metabolite changes suggesting reduced carbon flux through the lignin biosynthetic pathway and a shift towards allocation of secondary storage and defense metabolites, including various phenols, phenolic glucosides, and phenolic acid conjugates.

  17. 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.

  18. Root lattices and quasicrystals

    Science.gov (United States)

    Baake, M.; Joseph, D.; Kramer, P.; Schlottmann, M.

    1990-10-01

    It is shown that root lattices and their reciprocals might serve as the right pool for the construction of quasicrystalline structure models. All noncrystallographic symmetries observed so far are covered in minimal embedding with maximal symmetry.

  19. Modeling root reinforcement using root-failure Weibull survival function

    Directory of Open Access Journals (Sweden)

    M. Schwarz

    2013-03-01

    Full Text Available Root networks contribute to slope stability through complicated interactions that include mechanical compression and tension. Due to the spatial heterogeneity of root distribution and the dynamic of root turnover, the quantification of root reinforcement on steep slope is challenging and consequently the calculation of slope stability as well. Although the considerable advances in root reinforcement modeling, some important aspect remain neglected. In this study we address in particular to the role of root strength variability on the mechanical behaviors of a root bundle. Many factors may contribute to the variability of root mechanical properties even considering a single class of diameter. This work presents a new approach for quantifying root reinforcement that considers the variability of mechanical properties of each root diameter class. Using the data of laboratory tensile tests and field pullout tests, we calibrate the parameters of the Weibull survival function to implement the variability of root strength in a numerical model for the calculation of root reinforcement (RBMw. The results show that, for both laboratory and field datasets, the parameters of the Weibull distribution may be considered constant with the exponent equal to 2 and the normalized failure displacement equal to 1. Moreover, the results show that the variability of root strength in each root diameter class has a major influence on the behavior of a root bundle with important implications when considering different approaches in slope stability calculation. Sensitivity analysis shows that the calibration of the tensile force and the elasticity of the roots are the most important equations, as well as the root distribution. The new model allows the characterization of root reinforcement in terms of maximum pullout force, stiffness, and energy. Moreover, it simplifies the implementation of root reinforcement in slope stability models. The realistic quantification of root

  20. 新疆两种纤维亚麻胚轴段高频萌芽诱导%High Frequency Adventitious Budding Induction from Hypocotyls Segments of Two Kinds of Fiber Flax in Xinjiang

    Institute of Scientific and Technical Information of China (English)

    邓倩; 刘静文; 王伟; 计巧灵

    2012-01-01

    [目的]通过建立新疆主栽的两个纤维亚麻品种(范妮和天鑫3号)高频率不定芽离体再生体系,为进一步筛选其体细胞耐盐突变体奠定基础.[方法]以不同消毒剂处理种子,以下胚轴段为外植体,运用不同植物生长调节剂组合诱导胚轴段再生不定芽.[结果]两种种子在10%的H2O2中处理10 min灭菌效果最好;范妮不定芽诱导最适宜培养基为:MS+ BA 0.45 mg/L+ IAA 0.3 mg/L,不定芽诱导率达180%;天鑫3号不定芽诱导最适培养基为:MS+ BA 0.6 mg/L+ NAA 0.03 mg/L,不定芽的诱导率达到98%.[结论]不同的亚麻品种在下胚轴萌芽过程中对植物生长调节剂的配比和浓度的要求也不尽相同,探明了范妮和天鑫3号高频不定芽发生的最佳植物生长调节剂的组合和浓度.%[Objective] The purpose of this study was to lay the foundation for further screening of somatic salt tolerant mutants through establishment of high frequency in vitro regeneration system of adventitious buds of two species of flax ( Fany and Tianxin 3 ) that are mainly planted in Xinjiang. [ Method ] The seeds were sterilized with different disinfectants. With hypocotylar segments of the seeding as explants, regenerated adventitious buds in segments were induced by different combination and concentration of plant growth regulators. [Result] Sterilizing effects were more suitable for the two kinds seeds treated with 10% H2O2 for 10 min. The optimum medium for inducing adventitious buds from Fany hypocotyls was MS + BA 0. 45 mg/L + IAA 0. 3 mg/L, induction rate of adventitious bud reached 180%. The optimum medium for inducing adventitious buds from Tianxin 3 hypocotyls was MS + BA 0. 6 mg/L + NAA 0. 03 mg/L, induction rate of adventitious bud reached 98% . [ Conclusion ] The results showed that different species of flax need different combination and concentration of plant growth regulators for inducing adventitious buds from hypocotyls, and the optimum combination

  1. The "Green" Root Beer Laboratory

    Science.gov (United States)

    Clary, Renee; Wandersee, James

    2010-01-01

    No, your students will not be drinking green root beer for St. Patrick's Day--this "green" root beer laboratory promotes environmental awareness in the science classroom, and provides a venue for some very sound science content! While many science classrooms incorporate root beer-brewing activities, the root beer lab presented in this article has…

  2. 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.

  3. Study on Cutting Rooting Characteristics and Anatomical Observation of Lagerstroemia indica%紫薇扦插生根特征和形态解剖学研究

    Institute of Scientific and Technical Information of China (English)

    牛田; 王厚新; 张林; 李承秀; 魏秀英; 孙芳; 于永畅; 王长宪

    2013-01-01

    以紫薇岱宗2号品种当年生半木质化枝条和木质化枝条为试材,研究了扦插时期对插穗生根能力的影响,结果表明,半木质化枝条优于木质化枝条.通过对半木质化枝插穗生根过程进行形态学和解剖观察,表明插穗茎内无根原基,不定根原基为诱发型的,起源于维管形成层与初生射线的交叉处.%One - year - old semi - hard wood and hardwood of Lagerstroemia indica cultivar Daizong 2 were used as materials for studying the rooting ability during cutting. The results showed that the rooting ability of semi - hard wood cuttings was better than that of hardwood cuttings. The morphological and anatomical structure of semi - hard wood cuttings was observed during rooting process. The observation results showed that there was no root primordium in cutting stem; the adventitious root primordium belonged to the induced type and originated from the cross region of vascular cambium and primary rays.

  4. Study on Adventitious Music Elements in Wuhe Folksong%五河民歌中的外来音乐元素研究

    Institute of Scientific and Technical Information of China (English)

    王敬

    2015-01-01

    由于五河地处淮河中游,属南北过渡地带,以及战乱、灾害等产生的人口迁移,历史上五河出现了大量的移民,他们为五河民歌注入了新的音乐元素,拟从五河民歌词曲的大同小异、词同曲异、曲同词异三种情况对其中的外来音乐进行分析,凸显五河民歌南北兼容的过渡性音乐特点。%Wuhe is a place which lies in the middle stretches of the Huaihe River and in an intermediate region between the South and the North of China,historical turmoil of wars and natural disasters brought a considerable migrants here.They infused many new elements into the Wuhe folksong.By analyzing its ad-ventitious music from the three facts that its lyrics similar with melodies,same lyrics with different melo-dies and different lyrics with same melodies,it was well-established that Wuhe folksong are provided with the musical traits of transitional compatibilities of some other folksongs in Southern and Northern areas of China.

  5. 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.

  6. The Roots Of Alienation

    Science.gov (United States)

    Bronfenbrenner, Urie

    1973-01-01

    Alienation in our society takes several forms--withdrawal, hostility, or efforts to reform. The author traces the roots of alienation to our neglect of many of the needs of children, particularly their need for interaction with adults. Among his many recommendations are: modified work schedules to permit more time with children and systems for…

  7. 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

  8. Identification of QTLs for root characteristics in maize grown in hydroponics and analysis of their overlap with QTLs for grain yield in the field at two water regimes.

    Science.gov (United States)

    Tuberosa, Roberto; Sanguineti, Maria Corinna; Landi, Pierangelo; Giuliani, Marcella Michela; Salvi, Silvio; Conti, Sergio

    2002-01-01

    We investigated the overlap among quantitative trait loci (QTLs) in maize for seminal root traits measured in hydroponics with QTLs for grain yield under well-watered (GY-WW) and water-stressed (GY-WS) field conditions as well as for a drought tolerance index (DTI) computed as GY-WS/GY-WW. In hydroponics, 11, 7, 9, and 10 QTLs were identified for primary root length (R1L), primary root diameter (R1D), primary root weight (R1W), and for the weight of the adventitious seminal roots (R2W), respectively. In the field, 7, 8, and 9 QTLs were identified for GY-WW, GY-WS, and DTI, respectively. Despite the weak correlation of root traits in hydroponics with GY-WW, GY-WS, and DTI, a noticeable overlap between the corresponding QTLs was observed. QTLs for R2W most frequently and consistently overlapped with QTLs for GY-WW, GY-WS, and/or DTI. At four QTL regions, an increase in R2W was positively associated with GY-WW, GY-WS, and/or DTI. A 10 cM interval on chromosome 1 between PGAMCTA205 and php20644 showed the strongest effect on R1L, R1D, R2W, GY-WW, GY-WS, and DTI. These results indicate the feasibility of using hydroponics in maize to identify QTL regions controlling root traits at an early growth stage and also influencing GY in the field. A comparative analysis of the QTL regions herein identified with those described in previous studies investigating root traits in different maize populations revealed a number of QTLs in common.

  9. 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.

  10. Silicon Promotes Adventitious Shoot Regeneration and Enhances Salinity Tolerance of Ajuga multiflora Bunge by Altering Activity of Antioxidant Enzyme

    Directory of Open Access Journals (Sweden)

    Iyyakkannu Sivanesan

    2014-01-01

    Full Text Available We investigated the effect of Si concentration on shoot regeneration and salinity tolerance of Ajuga multiflora. Addition of Si to the shoot induction medium significantly increased the frequency of shoot induction. The average number of shoots regenerated per explant decreased on the medium containing NaCl alone, while there was less decrease when the shoot induction medium was supplemented with both NaCl and Si. The shoot induction percentage increased linearly with increasing concentration of Si in the NaCl containing medium. Addition of Si to the shoot induction medium significantly increased SOD, POD, APX, and CAT activity in regenerated shoot buds as compared with the control. The inclusion of Si to the NaCl containing medium significantly increased the SOD activity in leaves and roots, while it decreased POD, APX, and CAT activity in both organs. Scanning electron microscopic analysis showed that there are no distinct differences in the structure of stomata between the control and Si-treated plants. However, NaCl treatment significantly affected the structure and number of stomata as compared to the control. Wavelength dispersive X-ray analysis confirmed the high Si deposition in trichomes of plants grown in the Si containing medium but not in plants grown in the medium without Si.

  11. Hairy roots are more sensitive to auxin than normal roots

    OpenAIRE

    Shen, Wen Hui; Petit, Annik; Guern, Jean; Tempé, Jacques

    1988-01-01

    Responses to auxin of Lotus corniculatus root tips or protoplasts transformed by Agrobacterium rhizogenes strains 15834 and 8196 were compared to those of their normal counterparts. Three different types of experiments were performed, involving long-term, medium-term, or short-term responses to a synthetic auxin, 1-naphthaleneacetic acid. Root tip elongation, proton excretion by root tips, and transmembrane electrical potential difference of root protoplasts were measured as a function of exo...

  12. 抗松材线虫病赤松组培苗的生根与移栽研究%Study on rooting and transplanting of the tissue-cultured plantlets from Pinus densiflora with good resistance to pine wilt disease

    Institute of Scientific and Technical Information of China (English)

    秦莉; 吴小芹; 王张丽

    2011-01-01

    Factors influencing rooting and transplanting of tissue-cultured plantlets from Pinus densiflora with excellent resistance to pine wilt disease but poor ability of rooting were investigated. The results showed that the induction rate of the adventitious root reached 93% after treating the shoots at 17 ℃ for 5 days, and it was beneficial for adventitious root induction as adding 30-50 mg/L banana juice into the rooting medium with a controlled temperature of 25 ℃. To sterilize the transplant matrix at high temperature or with 0.2% KMnO4 for two times would be helpful for improving the survival ratio of the tissue-cultured plantlets. Spraying nutrition solution could stimulate the plantlets growth. This research contributed to improve the root induction and transplanting survival rate, which provided factory style breeding system and practice evidences.%以抗病性较好但不易生根的抗松材线虫病赤松无性系为试验材料,对影响组培苗生根移栽的因素进行了研究.结果表明:将待生根的丛生芽置于17 ℃条件下处理5 d后,不定根诱导率最高达93%;在生根培养基中添加30~50 mg/L香蕉汁有利于不定根诱导;对移栽基质进行高温灭菌或0.2%高锰酸钾消毒2次的处理均可有效提高组培苗移栽成活率;喷施营养液对组培苗的长势具有促进作用.

  13. Variation in root wood anatomy

    NARCIS (Netherlands)

    Cutler, D.F.

    1976-01-01

    Variability in the anatomy of root wood of selected specimens particularly Fraxinus excelsior L. and Acer pseudoplatanus L. in the Kew reference microscope slide collection is discussed in relation to generalised statements in the literature on root wood anatomy.

  14. Hairy roots are more sensitive to auxin than normal roots

    Science.gov (United States)

    Shen, Wen Hui; Petit, Annik; Guern, Jean; Tempé, Jacques

    1988-01-01

    Responses to auxin of Lotus corniculatus root tips or protoplasts transformed by Agrobacterium rhizogenes strains 15834 and 8196 were compared to those of their normal counterparts. Three different types of experiments were performed, involving long-term, medium-term, or short-term responses to a synthetic auxin, 1-naphthaleneacetic acid. Root tip elongation, proton excretion by root tips, and transmembrane electrical potential difference of root protoplasts were measured as a function of exogenous auxin concentration. The sensitivity of hairy root tips or protoplasts to exogenous auxin was found to be 100-1000 times higher than that of untransformed material. PMID:16593928

  15. Metagenomics at Grass Roots

    Indian Academy of Sciences (India)

    Sudeshna Mazumdar-Leighton; Vivek K Choudhary

    2017-03-01

    Metagenomics is a robust, interdisciplinary approach for studyingmicrobial community composition, function, and dynamics.It typically involves a core of molecular biology, microbiology,ecology, statistics, and computational biology. Excitingoutcomes anticipated from these studies include unravelingof complex interactions that characterize the ecologicalmilieu of microbial communities. Diverse habitats fromwhich metagenomes have been reported include human guts,caterpillar guts, thermal vents in oceans, ore deposits, polarcaps, and even soils that adhere to plant roots. Knowledgegenerated from metagenomic projects has tremendous potentialto benefit human health, agriculture, and ecosystemfunctions. This article provides a brief history of technicaladvances in metagenomics, including DNA sequencing methods,and some case studies. A specific example is providedof microbial metagenomes found at the roots of native grassspecies (family Poaceae) that can grow on degraded lands undergoingrevegetation.

  16. Negative phototropism of rice root

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@It is often believed that the stem of higher plants has characteristics of positive phototropism, and the root shows no phototropism or no sensitivity to light though the root of Arabdopsis was reported possessing characteristics of negative phototropism. In this study, a distinct negative phototropism of the root system of rice seedlings was observed.

  17. Rooting an Android Device

    Science.gov (United States)

    2015-09-01

    tools that grant root privileges for both Windows and Linux . For the Linux system, open a shell window and use “cd” command to change the directory...defined as a process of gaining administrative commands and functions of an operating system (OS). In order to monitor live network traffic on any... Linux -based or, in this case, Android system, it is necessary to have administrative rights to gain access to any of the hardware devices, such as the

  18. 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.

  19. Design, fabrication and perivascular implantation of bioactive scaffolds engineered with human adventitial progenitor cells for stimulation of arteriogenesis in peripheral ischemia.

    Science.gov (United States)

    Carrabba, M; De Maria, C; Oikawa, A; Reni, C; Rodriguez-Arabaolaza, I; Spencer, H; Slater, S; Avolio, E; Dang, Z; Spinetti, G; Madeddu, P; Vozzi, G

    2016-03-24

    Cell therapy represents a promising option for revascularization of ischemic tissues. However, injection of dispersed cells is not optimal to ensure precise homing into the recipient's vasculature. Implantation of cell-engineered scaffolds around the occluded artery may obviate these limitations. Here, we employed the synthetic polymer polycaprolactone for fabrication of 3D woodpile- or channel-shaped scaffolds by a computer-assisted writing system (pressure assisted micro-syringe square), followed by deposition of gelatin (GL) nanofibers by electro-spinning. Scaffolds were then cross-linked with natural (genipin, GP) or synthetic (3-glycidyloxy-propyl-trimethoxy-silane, GPTMS) agents to improve mechanical properties and durability in vivo. The composite scaffolds were next fixed by crown inserts in each well of a multi-well plate and seeded with adventitial progenitor cells (APCs, 3 cell lines in duplicate), which were isolated/expanded from human saphenous vein surgical leftovers. Cell density, alignment, proliferation and viability were assessed 1 week later. Data from in vitro assays showed channel-shaped/GPTMS-crosslinked scaffolds confer APCs with best alignment and survival/growth characteristics. Based on these results, channel-shaped/GPTMS-crosslinked scaffolds with or without APCs were implanted around the femoral artery of mice with unilateral limb ischemia. Perivascular implantation of scaffolds accelerated limb blood flow recovery, as assessed by laser Doppler or fluorescent microspheres, and increased arterial collaterals around the femoral artery and in limb muscles compared with non-implanted controls. Blood flow recovery and perivascular arteriogenesis were additionally incremented by APC-engineered scaffolds. In conclusion, perivascular application of human APC-engineered scaffolds may represent a novel option for targeted delivery of therapeutic cells in patients with critical limb ischemia.

  20. SIRT1 inhibits TNF-α-induced apoptosis of vascular adventitial fibroblasts partly through the deacetylation of FoxO1.

    Science.gov (United States)

    Wang, Weirong; Yan, Chunfang; Zhang, Jiye; Lin, Rong; Lin, Qinqin; Yang, Lina; Ren, Feng; Zhang, Jianfeng; Ji, Meixi; Li, Yanxiang

    2013-06-01

    Sirtuin 1 (SIRT1), a NAD(+)-dependent class III histone deacetylase, participates in regulating cellular apoptosis, senescence and metabolism by deacetylating histones and multiple transcription factors. In this study, we aimed to determine the effect of SIRT1 on the apoptosis of vascular adventitial fibroblasts (VAFs) and related signaling pathways. SIRT1 was found in the nucleus of VAFs and translocated into the cytoplasm in response to tumor necrosis factor-α (TNF-α). Moreover, SIRT1 protein expression was reduced in VAFs stimulated with TNF-α. In addition, TNF-α increased the apoptosis of VAFs. Activation of SIRT1 by resveratrol (RSV) or overexpression of SIRT1 attenuated TNF-α-induced VAF apoptosis by decreasing the percentage of apoptotic cells and cleaved caspase-3 protein expression and increasing the Bcl-2/Bax ratio. In contrast, inhibition of SIRT1 by sirtinol/nicotinamide or knockdown of SIRT1 enhanced apoptosis of VAFs. On the other hand, knockdown of FoxO1 reduced TNF-α-induced VAF apoptosis. SIRT1 interacted with FoxO1 in VAFs by the co-immunoprecipitation assay. Further study showed that RSV or SIRT1 overexpression decreased acetylated-FoxO1 (Ac-FoxO1) protein expression in VAFs stimulated with TNF-α. Knockdown of SIRT1 resulted in an increase in Ac-FoxO1 protein expression. Taken together, these findings indicate that SIRT1 inhibits the apoptosis of VAFs, whereas FoxO1 promotes VAF apoptosis. Furthermore, the inhibitory effect of SIRT1 on VAF apoptosis is partly mediated by the deacetylation of FoxO1.

  1. Root aeration improves growth and nitrogen accumulation in rice seedlings under low nitrogen.

    Science.gov (United States)

    Zhu, Jingwen; Liang, Jing; Xu, Zhihui; Fan, Xiaorong; Zhou, Quansuo; Shen, Qirong; Xu, Guohua

    2015-11-16

    In wetland soils, changes in oxygen (O2) level in the rhizosphere are believed to influence the behaviour of nutrients and their usage by plants. However, the effect of aeration on nitrogen (N) acquisition under different N supply conditions remains largely unknown. In this study, the rice cultivars Yangdao 6 (YD6, with higher root aerenchyma abundance) and Nongken 57 (NK57, with lower root aerenchyma abundance) were used to evaluate the effects of aeration on rice growth and N accumulation. Our results showed that the number of adventitious roots and the root surface area increased significantly, and ethylene production and aerenchyma formation decreased in both cultivars after external aeration (EA). Five N treatments, including no N (-N), 0.125 mM NH4NO3 (LN), 1.25 mM Ca(NO3)2 (NO3-N), 1.25 mM (NH4)2SO4 (NH4-N) and 1.25 mM NH4NO3 (N/N), were applied to YD6 and NK57 for 2 days under internal aeration or EA conditions. External aeration increased the root biomass in both cultivars and the shoot biomass in NK57 by 18-50 %. The total N concentrations in roots of YD6 grown under -N and LN and of NK57 grown under NO3-N were increased by EA. Expression of OsPAD4, one of four putative genes regulating aerenchyma formation, showed a similar pattern alongside changes in the ethylene level in the EA-treated rice irrespective of the N treatments. Furthermore, expression of the high-affinity nitrate transporter gene OsNRT2.1 was increased by EA under -N, LN and NO3-N conditions. Our data provide evidence of an interaction between O2 and the supply of N in ethylene production, aerenchyma formation and N nutrition through modification of the expression of OsPAD4 and OsNRT2.1.

  2. Relação do estado nutricional de minicepas com o enraizamento de miniestacas de eucalipto Relationship between the nutritional status of ministumps to the rooting of eucalypt minicuttings

    Directory of Open Access Journals (Sweden)

    Ana Catarina Monteiro Carvalho Mori da Cunha

    2009-06-01

    Full Text Available O enraizamento adventício de estacas é influenciado por fatores intrínsecos e extrínsecos do material vegetal, e o conhecimento da ação deles é fundamental para o sucesso da produção de mudas por miniestaquia. O objetivo deste trabalho foi avaliar o grau de associação entre o estado nutricional das minicepas e o enraizamento de miniestacas de eucalipto, cultivadas em minijardim clonal em tubetes com subirrigação. Foram utilizados dados de enraizamento de miniestacas e teores de nutrientes quantificados pelas análises químicas dos tecidos foliares. A taxa de enraizamento foi correlacionada com o estado nutricional das brotações. Verificou-se que a nutrição mineral desempenha papel importante no enraizamento adventício de modo genótipo-dependente, ou seja, há diferença de comportamento dos clones em relação ao efeito dos nutrientes no enraizamento das miniestacas. Com relação ao teor de K, Ca, Mg e Mn, não foi observada associação com as taxas de enraizamento. Quanto aos demais nutrientes, em pelo menos um clone, houve associação positiva ou negativa entre as variáveis analisadas, com grau variável de acordo com o clone e o nutriente.The adventitious rooting of cuttings is influenced by intrinsic and extrinsic factors of the plant material. The knowledge about the action mode of these factors upon rooting is fundamental for the successful production of clonal seedlings through minicuttings. The objective of this study was to evaluate the degree of association between the nutritional state of ministumps with the rooting of eucalypt minicuttings, grown in a clonal minigarden in tubes with subirrigation. Data from minicutting rooting and nutrient contents quantified by chemical analyses of the leaf tissues were used. The rooting rate was correlated with the nutritional status of the shoots. It was verified that mineral nutrition plays an important role in adventitious rooting in a genotype-dependent way, i.e, the

  3. Back to the roots!

    DEFF Research Database (Denmark)

    Woermann, Niklas

    2017-01-01

    This article argues that one can revive the critical edge that postmodernist theory has brought to marketing, thinking without subscribing to any particular school of (critical) theory by following the principle of methodological situationalism. The roots of postmodernist critique lie in careful...... of social order into account, hence fail to provide sensible insight. I propose the principle of methodological situationalism as a litmus test to the analytical strength of a theory or piece of research. The principle states that theoretically adequate accounts of social phenomena must be grounded...

  4. The Roots of Beowulf

    Science.gov (United States)

    Fischer, James R.

    2014-01-01

    The first Beowulf Linux commodity cluster was constructed at NASA's Goddard Space Flight Center in 1994 and its origins are a part of the folklore of high-end computing. In fact, the conditions within Goddard that brought the idea into being were shaped by rich historical roots, strategic pressures brought on by the ramp up of the Federal High-Performance Computing and Communications Program, growth of the open software movement, microprocessor performance trends, and the vision of key technologists. This multifaceted story is told here for the first time from the point of view of NASA project management.

  5. Influence of 1-p-D-arabinofuranosylcytosine on mitotic activity of apical meristem of onion (Allium cepa L. roots

    Directory of Open Access Journals (Sweden)

    M. Kuraś

    2015-01-01

    Full Text Available The influence of increasing cytosine arabinoside (ara-C concentration (50, 100, 300 and 500 μg/ml on the mitotic activity of the apical meristem of onion adventitious roots was investigated during 24-h incubation in ara-C and postincubation in water. Incubation in ara-C inhibits reversibly mitosis, the degree of inhibition being dependent on the concentration used. 50 μg/ml ara-C causes only a slight and transitional mitotic depression, while 100—500 μg/ml reduces the per cent of mitoses in various degrees after 12-h incubation whereas after 24 h all concentrations (100—500 reduce mitosis to the same level of about 2 per cent (80% inhibition. During postincubation in water there occurs after treatment with 100—500 μg/ml ara-C, a wave of highly synchronized mitoses with a peak after 12 h. The highest frequency of synchronized mitoses (60°/o appeared in roots treated with 300 μg/ml ara-C. The main wave is preceded by a small one with a peak after 2-4 h of postincubation. This seems to be the consequence of phases S and G2 inhibition by ara-C. It was found that under the influence of ara-C the per cent of mitoses with chromosome aberration and of cells with micronuclei increased only slightly.

  6. Underground riparian wood: 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

    Despite the potential importance of tree species in influencing the processes of wood recruitment, transport, retention, and decay that control river wood budgets, focus has been relatively limited on this theme within fluvial wood research. Furthermore, one of the least investigated topics is the belowground living wood component of riparian trees. This paper presents observations of the morphology and age of buried stem and coarse root structures of eight Populus nigra individuals located in the riparian woodland of two sites on the middle to lower Tagliamento River, Italy. This species was selected because of its wide distribution along European rivers and its frequent dominance of riparian woodland. Each tree was excavated by hand to expose a minimum of half of the root system with complete exposure of the main axis. Smaller roots were then removed and larger protruding roots cut back to permit access to the main axis. The excavated structures were photographed from multiple angles for photogrammetric modelling; the structure and character of the exposed sediments around the tree's main axis were recorded; and wood samples were taken from the main aboveground stem(s), sections of the main buried axis, and major roots for dendrochronological analysis. Results from these field observations and laboratory dating of the wood samples were combined to describe the belowground morphology of each tree and to draw inferences concerning the impact of fluvial disturbances. Common features of these excavated structures included: (i) rooting depths to below the bar surface where the original tree established, with many young roots also existing at depth; (ii) translocation of the main buried axis in a downstream direction; (iii) a main buried axis comprised mainly of stems that have become buried and then generated new shoots, including multistem patches, and adventitious roots; (iv) the presence of steps and bends in the main buried axis associated with the generation of

  7. [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.

  8. Multivariate ultrametric root counting

    CERN Document Server

    Avendano, Martin

    2011-01-01

    Let $K$ be a field, complete with respect to a discrete non-archimedian valuation and let $k$ be the residue field. Consider a system $F$ of $n$ polynomial equations in $K\\vars$. Our first result is a reformulation of the classical Hensel's Lemma in the language of tropical geometry: we show sufficient conditions (semiregularity at $w$) that guarantee that the first digit map $\\delta:(K^\\ast)^n\\to(k^\\ast)^n$ is a one to one correspondence between the solutions of $F$ in $(K^\\ast)^n$ with valuation $w$ and the solutions in $(k^\\ast)^n$ of the initial form system ${\\rm in}_w(F)$. Using this result, we provide an explicit formula for the number of solutions in $(K^\\ast)^n$ of a certain class of systems of polynomial equations (called regular), characterized by having finite tropical prevariety, by having initial forms consisting only of binomials, and by being semiregular at any point in the tropical prevariety. Finally, as a consequence of the root counting formula, we obtain the expected number of roots in $(K...

  9. 几种生长调节剂对马尾松插穗促根的效应%Effects of Root-inducing Regulators in Rooting of Cuttings from Pinus massoniana Lamb.

    Institute of Scientific and Technical Information of China (English)

    季孔庶; 王章荣; 陈天华; 王明庥

    2001-01-01

    Root-inducing treatments was used in cuttings from five years old ortets of Pinus massoniana Lamb. from Ji′an in Jiangxi P rovince. First S3307 later IBA treatments had no effect on raising root r ate. The fittest concentration of IBA was 200 mg*L-1 and S3307 was 100 mg*L-1. Of all the treatments, regulators M1 and M2, compounded by the author, were the best. They could raise the level of endogenous IAA,lo wer the levels of iPA、 ABA、GA1+3 and root inhibitors (MI3, MI5 and M I6, they were all flavoniods), and also weaden the activity of IAA-oxidase (I AAO) .As a result, the root rate was raised from 34 percent (CK) up to 90 and 8 4 percent respectively. And the sum of adventitious root and branch root, the l ength of the longest root and the total length of the roots, were notabely rais ed.Therefore, strong stecklings of Pinus massoniana Lamb. could be raised .%用生长调节剂处理5年生江西吉安种源马尾松插穗,发 现先用S3307后用IBA无效,先用IBA后用S3307使扦插成活率成倍提高,首次 以木本植物为材料佐证了植物生长调节剂的阶段性促根作用理论.单独使用时,IBA最适浓 度为200 mg*L-1,S3307最适浓度为100 mg*L-1.最佳处理为自制的 复配调节剂M1和M2,M1和M2通过提高插穗内源IAA,降低iPA、ABA和GA1+3和 内源抑制物——黄酮类MI3、MI5、MI6,减弱IAAO活性,使插穗生根率由对照的34%提 高到90%和84%,侧根数、不定根数、最长不定根长和根总长等4个生根性状显著增强,有利 于培养无性系壮苗.

  10. Removal of root filling materials.

    LENUS (Irish Health Repository)

    Duncan, H.F. Chong, B.S.

    2011-05-01

    Safe, successful and effective removal of root filling materials is an integral component of non-surgical root canal re-treatment. Access to the root canal system must be achieved in order to negotiate to the canal terminus so that deficiencies in the original treatment can be rectified. Since a range of materials have been advocated for filling root canals, different techniques are required for their removal. The management of commonly encountered root filling materials during non-surgical re-treatment, including the clinical procedures necessary for removal and the associated risks, are reviewed. As gutta-percha is the most widely used and accepted root filling material, there is a greater emphasis on its removal in this review.

  11. ROOT Tutorial for Summer Students

    CERN Document Server

    CERN. Geneva; Piparo, Danilo

    2015-01-01

    ROOT is a "batteries-included" tool kit for data analysis, storage and visualization. It is widely used in High Energy Physics and other disciplines such as Biology, Finance and Astrophysics. This event is an introductory tutorial to ROOT and comprises a front lecture and hands on exercises. IMPORTANT NOTE: The tutorial is based on ROOT 6.04 and NOT on the ROOT5 series.  IMPORTANT NOTE: if you have ROOT 6.04 installed on your laptop, you will not need to install any virtual machine. The instructions showing how to install the virtual machine on which you can find ROOT 6.04 can be found under "Material" on this page.

  12. Comparing Leaf and Root Insertion

    Directory of Open Access Journals (Sweden)

    Jaco Geldenhuys

    2010-07-01

    Full Text Available We consider two ways of inserting a key into a binary search tree: leaf insertion which is the standard method, and root insertion which involves additional rotations. Although the respective cost of constructing leaf and root insertion binary search trees trees, in terms of comparisons, are the same in the average case, we show that in the worst case the construction of a root insertion binary search tree needs approximately 50% of the number of comparisons required by leaf insertion.

  13. 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…

  14. Properties of Estimated Characteristic Roots

    DEFF Research Database (Denmark)

    Nielsen, Bent; Nielsen, Heino Bohn

    Estimated characteristic roots in stationary autoregressions are shown to give rather noisy information about their population equivalents. This is remarkable given the central role of the characteristic roots in the theory of autoregressive processes. In the asymptotic analysis the problems appear...

  15. Searching for Roots / Pierre Gervasoni

    Index Scriptorium Estoniae

    Gervasoni, Pierre

    1997-01-01

    Uuest heliplaadist "Searching for Roots. Eduard Tubin: Symphonie no 11; Arvo Pärt: Nekrolog-Symphonie no 1; Erkki-Sven Tüür: Searching for Roots - Insula deserta - Zeitraum; Orchestre philharmonique royal de Stockholm, Paavo Järvi (direction)" Virgin Classics 5 45212 2 (distribue par EMI)

  16. 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)

  17. 血管外膜肌成纤维细胞分化的基因表达谱%Gene profile for differentiation of vascular adventitial myofibroblasts

    Institute of Scientific and Technical Information of China (English)

    郭淑杰; 吴凌云; 沈伟利; 陈闻东; 魏坚; 高平进; 朱鼎良

    2006-01-01

    我们以往的研究表明,TGF-β1可以诱导血管外膜成纤维细胞(adventitial fibroblasts,AFs)向肌成纤维细胞(myofibroblasts,MFs)分化.为寻找可能涉及MF分化的基因,本实验采用寡核苷酸芯片技术动态检测细胞表型转化过程中基因表达的变化,实时定量RT-PCR验证芯片结果.在芯片上的15 866条总探针组中,2 121个探针组在TGF-β1刺激后至少一个时间点的表达发生2倍以上变化,其中1 318个基因表达上调,761个基因表达下调,还有少数基因(42个)在不同的时间点既有上调又有下调表达.在1 231个已知功能基因中,分泌磷蛋白1(secreted phosphoprotein 1,APP1)、Rho-associated coiled-coil forming kinase 2(ROCK2)的表达趋势与标志基因α-平滑肌肌动蛋白(α-SM-actin)的表达趋势相同,TGF-β1诱导MF分化过程中上调了电压门控性钾通道Shal家族成员2(potassiumvoltage-gated channel,Shal-related family and member 2,KCND2)的表达,这些基因参与了MF的分化;此外,还发现内皮素1(endothelin 1,EDN1)、补体成分、NADPH氧化酶4(NADPH oxidase 4,NOX4)和NAD(P)H dehydrogenase,quinone 1(NQO1)可能参与了MF分化.本实验用寡核苷酸芯片技术验证了通过其它技术证实的同MF分化相关的基因,并发现了新的涉及该过程的基因,基因表达谱研究有利于鉴定参与细胞分化的基因和通路.%Our previous study demonstrated that TGF-β1 could induce the differentiation of vascular adventitial fibroblasts (AFs) to myofibroblasts (MFs). The aim of this study was to identify the genes which might be responsible for the cell phenotypic change using genechips. Cultured rat AFs were treated with TGF-β1 (10 ng/ml) for 0 min, 5 min, 15 min, 2 h, 12 h and 24 h, respectively. Then the cells were gathered to prepare total RNA. We examined TGF-β1-induced gene expression profiling using Affymetrix oligonucleotide microarrays and analyzed data by GCOS 1.2 software. Moreover, expressional similarity was

  18. 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.

  19. Anatomical Structure of Stem and Adventitious Root Formation of Feijoa Cuttings%费约果茎解剖结构与插条不定根的形成

    Institute of Scientific and Technical Information of China (English)

    张猛; 王丹; 汤浩茹; 任少雄; 刘仁道

    2010-01-01

    @@ 费约果(Feijoa sellowiana)是桃金娘科多年生亚热带常绿灌木,原产于巴西东南部和乌拉圭,因其果实香味类似凤梨(Ananas comosus),又名凤梨番石榴(Thorp et al.,2002).费约果在新西兰、美国、法国、西班牙、俄罗斯、澳大利亚、日本等国有栽培,我国江苏、上海、四川、浙江等南方地区也有一定规模的种植.费约果作为一种集观赏、食用与药用为一体的新兴果树,在食品、药品、化妆品等领域具有广阔的应用前景(Nakashima,2001;Hardy et al.,1970;Kolesnik et al.,1991).在四川省外国专家局引智项目资助下,2004年,西南科技大学王丹教授从新西兰引进少量费约果苗木后,对其在四川地区的适应性以及综合性状进行了初步研究,认为费约果能够适应四川地区气候,并能保持其优良的食用与观赏特性,是一种极具发展潜力的食用兼观赏的树种(王丹等,2007).

  20. Effects of different temperatures on growth and root antioxidant enzyme activities of banana adventitious bud%温度对香蕉不定芽生长及抗氧化酶活性的影响

    Institute of Scientific and Technical Information of China (English)

    丰锋; 叶银芳; 叶春海

    2016-01-01

    为探明温度对香蕉不定芽生长及根系活力的影响,以巴西香蕉(Musa paradisiaca)为材料,在人工气候箱条件下研究温度对香蕉不定芽生长及抗氧化酶活性的影响.结果表明:SOD活性呈现上升-下降波动变化,POD活性先上升,培养15 ~20 d达到最高后下降,培养45 d后又缓慢上升,CAT活性整体先下降,培养45d后上升;在30℃以内,随温度升高,根系活力逐渐增加,培养20 d后游离脯氨酸含量随温度升高而上升,培养50 d开始下降,MDA含量先逐渐下降后上升,培养20 d和45 d较低;30℃最适宜香蕉不定芽生长,此条件下培养25 d根系活力达最高(11.92 mg/g·h),游离脯氨酸(58.76 μg/g)和MDA含量(7.15 nmol/g)都较低,根茎叶生长旺盛(苗高5.02 cm、叶数3.64片、根数4.63条、根长4.91 cm),是最适宜移栽的时间;培养45 d根系活力为2.33 mg/g·h,游离脯氨酸(94.83μg/g)和MDA含量(9.83nmol/g)都较低,根茎叶生长旺盛(苗高6.15 cm、叶数4.97片、根数6.01条、根长6.06 cm),是次适宜移栽的时间.30℃最适宜香蕉不定芽的生长,培养25 d是最适宜移栽的时间.

  1. Medico-legal aspects of vertical root fractures in root filled teeth

    DEFF Research Database (Denmark)

    Rosen, E; Tsesis, I; Tamse, A;

    2012-01-01

    To analyse the medico-legal aspects of vertical root fracture (VRF) following root canal treatment (RCT).......To analyse the medico-legal aspects of vertical root fracture (VRF) following root canal treatment (RCT)....

  2. 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

  3. 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

  4. 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

  5. An adventitious new Deschampsia species

    NARCIS (Netherlands)

    Kloos, A.W.

    1946-01-01

    On the 13th of October 1940 I found in the vicinity of a wool- and skinwork in Tilburg (The Netherlands, prov. N. Brabant) a sterile grasstuft, striking me by its peculiar habit. I transplanted it into my garden in Dordrecht and there it was flowering for the first time in June 1941, and in July it

  6. [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.

  7. Sublethal concentrations of salicylic acid decrease the formation of reactive oxygen species but maintain an increased nitric oxide production in the root apex of the ethylene-insensitive never ripe tomato mutants.

    Science.gov (United States)

    Tari, Irma; Poór, Péter; Gémes, Katalin

    2011-09-01

    The pattern of salicylic acid (SA)-induced production of reactive oxygen species (ROS) and nitric oxide (NO) were different in the apex of adventitious roots in wild-type and in the ethylene-insensitive never ripe (Nr) mutants of tomato (Solanum lycopersicum L. cv Ailsa Craig). ROS were upregulated, while NO remained at the control level in apical root tissues of wildtype plants exposed to sublethal concentrations of SA. In contrast, Nr plants expressing a defective ethylene receptor displayed a reduced level of RO S and a higher NO content in the apical root cells. In wild-type plants NO production seems to be RO S(H2O2)-dependent at cell death-inducing concentrations of SA, indicating that ROS and NO may interact to trigger oxidative cell death. In the absence of significant RO S accumulation, the increased NO production caused moderate reduction in cell viability in root apex of Nr plants exposed to 10(-3) M SA. This suggests that a functional ethylene signaling pathway is necessary for the control of ROS and NO production induced by SA.

  8. Eficiência das auxinas (AIB e ANA no enraizamento de miniestacas de clones de Eucalyptus cloeziana F. Muell Auxin (IBA and NAA effects on minicuttings rooting of Eucalyptus cloeziana F. Muell. clones

    Directory of Open Access Journals (Sweden)

    Fernanda Daniele de Almeida

    2007-01-01

    Full Text Available Este trabalho teve como objetivo avaliar a eficiência das auxinas AIB (ácido indolbutírico e ANA (ácido naftalenoacético no enraizamento adventício de miniestacas de clones de Eucalyptus cloeziana. Foram utilizadas miniestacas provenientes de sete clones de Eucalyptus cloeziana, estabelecidos em minijardim clonal, sendo avaliados os efeitos de AIB (0, 1.500, 3.000 e 6.000 mg L-1 na forma líquida e em pó e ANA (0, 3.000 e 6.000 mg L-1 na forma líquida. Os resultados apontaram ser a miniestaquia técnica viável na propagação vegetativa dos clones de Eucalyptus cloeziana estudados, apresentando, de modo geral, alto índice de enraizamento das miniestacas. Os clones com maior potencial de enraizamento adventício responderam mais positivamente às menores dosagens de AIB, enquanto nos clones com capacidade de enraizamento reduzida houve tendência de as maiores dosagens de AIB serem mais eficientes no enraizamento, independentemente da forma de aplicação do fitorregulador (líquido ou pó. O ANA, de modo geral, não influenciou significativamente o enraizamento das miniestacas da maioria dos clones estudados.The present work aimed to evaluate the efficiency of the auxins IBA (indolbutyric acid and NAA (naphtaleneacetic acid on the adventitious rooting of Eucalyptus cloeziana clones. Minicuttings originated from seven Eucalyptus cloeziana clones established in mini-clonal hedge, were evaluated for the effects of IBA (0, 1500, 3000 and 6000 mg L-1 in the liquid and powder forms and NAA (0, 3000 and 6000 mg L-1 in the liquid form. The results showed that minicutting is a viable technique for vegetative propagation of the studied Eucalyptus cloeziana clones, with overall high rooting rates. Clones with higher adventitious rooting potential gave better response to lower IBA doses, while clones with reduced rooting potential were more efficient with higher doses, independently of the form of the applied phytoregulator (powder or liquid. NAA

  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. How Can Science Education Foster Students' Rooting?

    Science.gov (United States)

    Østergaard, Edvin

    2015-01-01

    The question of how to foster rooting in science education points towards a double challenge; efforts to "prevent" (further) uprooting and efforts to "promote" rooting/re-rooting. Wolff-Michael Roth's paper discusses the uprooting/rooting pair of concepts, students' feeling of alienation and loss of fundamental sense of the…

  11. Influência do estado nutricional de minicepas no enraizamento de miniestacas de eucalipto Influence of the nutritional status of ministumps on the rooting of eucalypt minicuttings

    Directory of Open Access Journals (Sweden)

    Ana Catarina Monteiro Carvalho Mori da Cunha

    2009-08-01

    Full Text Available O enraizamento adventício de estacas é influenciado por fatores intrínsecos e extrínsecos do material vegetal. O conhecimento sobre o modo de ação desses fatores sobre o enraizamento é fundamental para o sucesso da produção de mudas por miniestaquia. Entre os fatores envolvidos no enraizamento, pode-se destacar a nutrição mineral, pois existe significativa relação entre ela e o enraizamento. No entanto, a importância de vários nutrientes nesse processo ainda não está totalmente esclarecida. Diante do exposto, o objetivo deste trabalho foi avaliar o grau de associação linear entre o estado nutricional das minicepas com o enraizamento de miniestacas de eucalipto. Foram utilizados dados da empresa CENIBRA, entre os quais se analisaram os de enraizamento de miniestacas e dos teores de nutrientes revelados por análises químicas dos tecidos foliares das minicepas. Os dados usados foram originados de minijardim clonal cultivado em leito de areia, com fertirrigação por gotejamento. Com esses dados, foram realizadas análises para avaliar a existência de correlação linear entre as concentrações de macro e micronutrientes nas minicepas e a taxa de enraizamento das miniestacas. Os resultados indicaram que a nutrição mineral desempenha papel importante no enraizamento adventício das miniestacas produzidas pelas minicepas, gerando respostas diferenciadas de acordo com o nutriente considerado. Os resultados evienciaram que a solução nutritiva aplicada no minijardim clonal deve ser específica para cada clone.The adventitious rooting of cuttings is influenced by intrinsic and extrinsic factors of the plant material. The knowledge about the way of the action of these factors upon rooting is essential for the success of the seedling production by minicuttings. Among the factors involved in rooting the mineral nutrition can be emphasized because there is a significant relation between it and rooting, but the importance of various

  12. MES buffer affects Arabidopsis root apex zonation and root growth by suppressing superoxide generation in root apex

    Directory of Open Access Journals (Sweden)

    Tomoko eKagenishi

    2016-02-01

    Full Text Available In plants, growth of roots and root hairs is regulated by the fine cellular control of pH and reactive oxygen species. MES, 2-(N-morpholinoethanesulfonic acid as one of the Good’s buffers has broadly been used for buffering medium, and it is thought to suit for plant growth with the concentration at 0.1% (w/v because the buffer capacity of MES ranging pH 5.5-7.0 (for Arabidopsis, pH 5.8. However, many reports have shown that, in nature, roots require different pH values on the surface of specific root apex zones, namely meristem, transition zone and elongation zone. Despite the fact that roots always grow on a media containing buffer molecule, little is known about impact of MES on root growth. Here, we have checked the effects of different concentrations of MES buffer using growing roots of Arabidopsis thaliana. Our results show that 1% of MES significantly inhibited root growth, the number of root hairs and length of meristem, whereas 0.1% promoted root growth and root apex area (region spanning from the root tip up to the transition zone. Furthermore, superoxide generation in root apex disappeared at 1% of MES. These results suggest that MES disturbs normal root morphogenesis by changing the reactive oxygen species (ROS homeostasis in root apex.

  13. Magnetophoretic Induction of Root Curvature

    Science.gov (United States)

    Hasenstein, Karl H.

    1997-01-01

    The last year of the grant period concerned the consolidation of previous experiments to ascertain that the theoretical premise apply not just to root but also to shoots. In addition, we verified that high gradient magnetic fields do not interfere with regular cellular activities. Previous results have established that: (1) intracellular magnetophoresis is possible; and (2) HGMF lead to root curvature. In order to investigate whether HGMF affect the assembly and/or organization of structural proteins, we examined the arrangement of microtubules in roots exposed to HGMF. The cytoskeletal investigations were performed with fomaldehyde-fixed, nonembedded tissue segments that were cut with a vibratome. Microtubules (MTs) were stained with rat anti-yeast tubulin (YOL 1/34) and DTAF-labeled antibody against rat IgG. Microfilaments (MFs) were visualized by incubation in rhodamine-labeled phalloidin. The distribution and arrangement of both components of the cytoskeleton were examined with a confocal microscope. Measurements of growth rates and graviresponse were done using a video-digitizer. Since HGMF repel diamagnetic substances including starch-filled amyloplasts and most The second aspect of the work includes studies of the effect of cytoskeletal inhibitors on MTs and MFs. The analysis of the effect of micotubular inhibitors on the auxin transport in roots showed that there is very little effect of MT-depolymerizing or stabilizing drugs on auxin transport. This is in line with observations that application of such drugs is not immediately affecting the graviresponsiveness of roots.

  14. Capturing Arabidopsis Root Architecture Dynamics with root-fit Reveals Diversity in Responses to Salinity

    NARCIS (Netherlands)

    Julkowska, M.M.; Hoefsloot, H.C.J.; Mol, S.; Feron, R.; de Boer, G.J.; Haring, M.A.; Testerink, C.

    2014-01-01

    The plant root is the first organ to encounter salinity stress, but the effect of salinity on root system architecture (RSA) remains elusive. Both the reduction in main root (MR) elongation and the redistribution of the root mass between MRs and lateral roots (LRs) are likely to play crucial roles i

  15. Retention of Root Canal Posts

    DEFF Research Database (Denmark)

    Sahafi, A; Benetti, Ana Raquel; Flury, S;

    2015-01-01

    The aim of this study was to investigate the effect of the cement film thickness of a zinc phosphate or a resin cement on retention of untreated and pretreated root canal posts. Prefabricated zirconia posts (CosmoPost: 1.4 mm) and two types of luting cements (a zinc phosphate cement [DeTrey Zinc......] and a self-etch adhesive resin cement [Panavia F2.0]) were used. After removal of the crowns of 360 extracted premolars, canines, or incisors, the root canals were prepared with a parallel-sided drill system to three different final diameters. Half the posts did not receive any pretreatment. The other half...... received tribochemical silicate coating according to the manufacturer's instructions. Posts were then luted in the prepared root canals (n=30 per group). Following water storage at 37°C for seven days, retention of the posts was determined by the pull-out method. Irrespective of the luting cement...

  16. Descendant root volume varies as a function of root type: estimation of root biomass lost during uprooting in Pinus pinaster

    Directory of Open Access Journals (Sweden)

    Frédéric eDanjon

    2013-10-01

    Full Text Available Root systems of woody plants generally display a strong relationship between the cross-sectional area (CSA or cross-sectional diameter (CSD of a root and the dry weight of biomass (DWd or root volume (Vd that has grown (i.e., is descendent from that point. Specification of this relationship allows one to quantify root architectural patterns and estimate the amount of material lost when root systems are extracted from the soil. However, specifications of this relationship generally do not account for the fact that root systems are comprised of multiple types of roots. We assessed whether the relationship between CSD and Vd varies as a function of root type. Additionally, we sought to identify a more accurate and time-efficient method for estimating missing root volume than is currently available.We used a database that described the 3D root architecture of Pinus pinaster root systems (5, 12, or 19 yr from a stand. We determined the relationship between CSD and Vd for 10,000 root segments from intact root branches. Models were specified that did and did not account for root type. The relationships were then applied to the diameters of 11,000 broken root ends to estimate the volume of missing roots.CSD was nearly linearly related to the square root of Vd, but the slope of the curve varied greatly as a function of root type. Sinkers and deep roots tapered rapidly, as they were limited by available soil depth. Distal shallow roots tapered gradually, as they were less limited spatially. We estimated that younger trees lost an average of 17% of root volume when excavated, while older trees lost 4%. Missing volumes were smallest in the central parts of root systems and largest in distal shallow roots.The slopes of the curves for each root type are synthetic parameters that account for differentiation due to genetics, soil properties, or mechanical stimuli. Accounting for this differentiation is critical to estimating root loss accurately.

  17. Grass Roots War on Poverty

    OpenAIRE

    Amsden, Alice H

    2012-01-01

    Sub-Saharan Africa’s failure to slay the dragon of poverty is due to a logical flaw in its policies: the remedies to reduce poverty don’t address the causes. Poverty is caused by unemployment, owing to a scarcity of jobs that pay above bare subsistence, but grass-roots poverty alleviation measures are exclusively designed to make job-seekers more capable although no jobs are available. The ‘appropriate’ technologies of the grass roots movement that dominates anti-poverty policies are ...

  18. An Efficient Method for Adventitious Shoot Regeneration from Leaf and Stem-segment Explants of Russian Olive Elaeagnus angustifolia L.%采用俄罗斯橄榄叶片和茎段诱导产生不定芽的高效再生方法

    Institute of Scientific and Technical Information of China (English)

    卢松冲; 朱金启; 李杰; 张洪霞

    2011-01-01

    The establishment of an efficient adventitious shoot regeneration system from leaf discs and stem segments of one-year-old Russian olive ( Elaeagnus angustifolia L. ) was established. Shoot regeneration using leaf explants and stem segments was obtained on MS medium supplemented with different cytokinins viz., 6-benzyladenine (BA) and Zeatin (Zt), with combination of auxins viz. , naphthaleneacetic acid (NAA) and indole-3-butyric acid (IBA). MS + 0.5mg/L 6-BA + 0.2mg/L NAA was found to be a better combination for leaf regeneration, producing a maximum of 4.3 shoots per explant, whereas MS + 1. 0mg/L Zt +0.5mg/L NAA for stem-segment explants produced the highest number of multiple shoots (3.6) per explant. The regenerated shoots produced 100% rooting on 1/2 strength MS medium supplied with 0.5mg/L NAA. In vitro raised plantlets were successfully transferred to pots containing sterile soil: peat moss: sand ( 1 : 1 : 1 ) for acclimatization, and 77% of rooted plantlets survived under ex situ conditions. The currently employed regeneration protocol through leaf explants and stem segments facilitates germplasm conservation of this medicinally and ecologically important species besides providing a standardized regeneration protocol for genetic transformation studies in the future.%俄罗斯橄榄(Elaeagnus angustifolia L.)是一种具有很重要药用价值和生态意义的植物.以俄罗斯橄榄一年生幼苗的叶片和茎段为实验材料,探讨了细胞分裂素类(6-BA和Zt)和生长素类(NAA和IBA)两类激素不同组合以及不同配比对植株再生的影响,最后建立了一个高效的俄罗斯橄榄再生方法.结果表明,MS培养基+0.5 mg/L 6-BA+0.2 mg/L NAA更适合叶片的再生,平均每个外植体能产生多达4.3个不定芽;而在MS培养基+1.0 mg/L Zt+0.5 mg/L NAA的条件下,茎段外植体再生出来的不定芽最多可以达到平均3.6个;再生芽在含有0.5 mg/L NAA的1/2 MS培养基上生根率达到100%.体外再生苗移

  19. Evaluation for Plant Regeneration Potential of Root Explants in Echinacea purpurea%松果菊根外植体植株再生能力的评价

    Institute of Scientific and Technical Information of China (English)

    Dahanayake NILANTHI; 赵福成; 杨跃生; 吴鸿

    2009-01-01

    为了评价松果菊Echinacea purpurea L.根外植体的再生能力,将从松果菊无菌小苗得到的根外植体和叶片以及叶柄外植体接种到含有不同种类和浓度的细胞分裂素和生长素的培养基上,诱导不定芽的再生.结果表明,在多数情况下,根外植体的再生能力显著高于叶片,和叶柄类似.0.3 mg/L的苄基腺嘌呤和0.01 mg/L的萘乙酸是诱导根外植体不定芽再生最合适的激素种类和质量浓度组合.根外植体培养的不定芽再生频率为100%,每个根外植体得到再生芽1.75个.当把这些由根再生的不定芽从母体组织切开并转移培养到含有0.01 mg/L萘乙酸的培养基后,很容易生根并成为完整的植株.可见根是组培快繁松果菊理想的外植体材料.%For evaluation of the plant regeneration potential of root explants, explants of root, leaf and petiole were taken from in vitro grown purple coneflower, Echinacea purpurea L. Plantlets and cultured on adventitious bud inducing media with different cytokinins and auxins at various concentrations. In most of the cases, the regeneration potential of root explants was much higher than that of leaf ones and similar to that of petiole explants, and a combination of 0.3 mg/L benzyladeine with 0.01 mg/L naphthaleneacetic acid was the most effective combination and concentrations for inducing adventitious bud regen-eration. Although the best result of bud regeneration was obtained from culture of petiole explants, a good result in regenera-tion rate of 100% and a high number of 1.75 buds per exphnt were obtained from culture of root explants. Buds regenerated from root explants initiated roots and became intact plants readily upon transfer to a medium containing 0.01 mg/L naphthale-neacetic acid. Results of the experiments indicated that root was an ideal explant source for rapid propagation by means of tis-sue culture in this plant species.

  20. Root growth, secondary root formation and root gravitropism in carotenoid-deficient seedlings of Zea mays L

    Science.gov (United States)

    Ng, Y. K.; Moore, R.

    1985-01-01

    The effect of ABA on root growth, secondary-root formation and root gravitropism in seedlings of Zea mays was investigated by using Fluridone-treated seedlings and a viviparous mutant, both of which lack carotenoids and ABA. Primary roots of seedlings grown in the presence of Fluridone grew significantly slower than those of control (i.e. untreated) roots. Elongation of Fluridone-treated roots was inhibited significantly by the exogenous application of 1 mM ABA. Exogenous application of 1 micromole and 1 nmole ABA had either no effect or only a slight stimulatory effect on root elongation, depending on the method of application. The absence of ABA in Fluridone-treated plants was not an important factor in secondary-root formation in seedlings less than 9-10 d old. However, ABA may suppress secondary-root formation in older seedlings, since 11-d-old control seedlings had significantly fewer secondary roots than Fluridone-treated seedlings. Roots of Fluridone-treated and control seedlings were graviresponsive. Similar data were obtained for vp-9 mutants of Z. mays, which are phenotypically identical to Fluridone-treated seedlings. These results indicate that ABA is necessary for neither secondary-root formation nor for positive gravitropism by primary roots.

  1. Four cuspal maxillary second premolar with single root and three root canals: Case report

    Directory of Open Access Journals (Sweden)

    Parul Bansal

    2016-01-01

    Full Text Available Traditional configuration of maxillary second premolars has been described to have two cusps, one root and one or two root canals. The endodontic literature reports considerable anatomic aberrations in the root canal morphology of maxillary second premolar but the literature available on the variation in cuspal anatomy and its relationship to the root canal anatomy is sparse. The purpose of this clinical report was to describe the root and root canal configuration of a maxillary second premolar with four cusps.

  2. 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,…

  3. Cutting the Roots of Violence.

    Science.gov (United States)

    Koziey, Paul W.

    1996-01-01

    Violence is rooted in obedience to authority and in comparisons--foundations of our institutions of parenting and schooling. Obedience brings reward and punishment, comparison perpetuates a cycle of competition and conflict. Television violence is especially harmful because children easily understand visual images. The Reality Research approach to…

  4. Disease notes - Bacterial root rot

    Science.gov (United States)

    Bacterial root rot initiated by lactic acid bacteria, particularly Leuconostoc, occurs every year in Idaho sugarbeet fields. Hot fall weather seems to make the problem worse. Although Leuconostoc initiates the rot, other bacteria and yeast frequently invade the tissue as well. The acetic acid bac...

  5. 发根农杆菌K599对菊花活体转化及其高效再生%Hairy Roots Induced by Agrobacterium rhizogenes K599 in Chrysanthemum in Vivo and Plant Regeneration from Hairy Roots

    Institute of Scientific and Technical Information of China (English)

    向太和; 王琳; 蒋欢; 田璟鸾

    2011-01-01

    The transgenic hairy roots were formed on cut leaves of chrysanthemum plantlet by Agrobacterium rhizogenes K599 with frequencies of 88.0%.The calli were induced from hairy roots and plantlets were regenerated from calli at rates of 75.0% and 63.3% respectively.The transgenic hairy roots and plantlet were confirmed by PCR analysis with primers from K599 Ri plasmid rolC gene.Quantitative RT-PCR(qRT-PCR)analysis showed that rolC gene was normally expressed in the regenerated transgenic plants.Regenerated plants harbored a character of dwarf,more hairy roots and flowering normally.Organism in vivo directly as a receptor for infection by Agrobacterium rhizogenes K599,it overcame the emergence of false-positive transgenic hairy roots.In addition,using the process of hairy roots propagation characteristics of the top growing point region sterile and the interception of adventitious roots near the growing point to the top for subculture,combined with cefotaxime sterilization,it can inhibit and kill the Agrobacterium effectively.In the subsequent callus induction and redifferentiation from hairy roots,it is no antibiotics added to medium for killing Agrobacterium.It genetically enhanced efficiency of plant regeneration.The transgenic hairy roots were induced by Agrobacterium rhizogenes K599 in chrysanthemum in vivo and plant regenerated from hairy roots highly efficiently in the study.It is useful to dwarf breeding and the target gene transformation of chrysanthemum.%发根农杆菌K599侵染菊花无菌苗刻伤的叶片形成转基因不定根,生根频率为88.0%;不定根经过诱导培养形成愈伤组织,并再生完整植株,愈伤组织诱导率和分化率分别为75.0%和63.3%。诱导的不定根和再生植株经过PCR鉴定含有K599 Ri质粒中的rolC基因,qRT-PCR检测显示rolC基因在再生转基因植株中实现了正常表达。再生植株表现出矮缩、多毛状根特征,并能正常开花。建立的利用活体材料

  6. [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.

  7. Enraizamento de estacas de Sebastiania schottiana Müll. Arg. Rooting of Sebastiania schottiana Müll. Arg. cuttings

    Directory of Open Access Journals (Sweden)

    Eduardo Garcia Frassetto

    2010-12-01

    trial, basal, median and apical cuttings had their bases immersed in Orgasol® FTS at levels of 0, 5, 10 and 15mL L-1, for 1 minute. The experimental design was in random blocks, with three replicates and 20 cuttings per plot. At 75 days, the rooted cuttings percentage, the length and diameter of the longest root were evaluated. In a second trial, basal and median cuttings were treated for 0, 15, 30 and 45 minutes in 15mL L-1 of Orgasol® FTS. The experimental design was in random blocks, with three replicates of 20 cuttings per plot. At 150 day, the rooted cuttings percentage, dry roots mass and the length and diameter of the longest root were evaluated. In the first trial, higher levels of product was beneficial to rooting, it was observed the largets rooted cuttings percentage in the treatment with 15mL L-1 of product. In second trial, the higher rooting potential was observed in the basal and median cuttings treated by 45 minutes in 15mL L-1 of product. The use of orgasol® FTS promotes adventitious roots in Sebastiania schottiana cuttings.

  8. Characterizing pathways by which gravitropic effectors could move from the root cap to the root of primary roots of Zea mays

    Science.gov (United States)

    Moore, R.; McClelen, C. E.

    1989-01-01

    Plasmodesmata linking the root cap and root in primary roots Zea mays are restricted to approx. 400 protodermal cells bordering approx. 110000 microns2 of the calyptrogen of the root cap. This area is less than 10% of the cross-sectional area of the root-tip at the cap junction. Therefore, gravitropic effectors moving from the root cap to the root can move symplastically only through a relatively small area in the centre of the root. Decapped roots are non-responsive to gravity. However, decapped roots whose caps are replaced immediately after decapping are strongly graviresponsive. Thus, gravicurvature occurs only when the root cap contacts the root, and symplastic continuity between the cap and root is not required for gravicurvature. Completely removing mucilage from the root tip renders the root non-responsive to gravity. Taken together, these data suggest that gravitropic effectors move apoplastically through mucilage from the cap to the root.

  9. Dynamics of heterorhizic root systems: protoxylem groups within the fine-root system of Chamaecyparis obtusa.

    Science.gov (United States)

    Hishi, Takuo; Takeda, Hiroshi

    2005-08-01

    To understand the physiology of fine-root functions in relation to soil organic sources, the heterogeneity of individual root functions within a fine-root system requires investigation. Here the heterogeneous dynamics within fine-root systems are reported. The fine roots of Chamaecyparis obtusa were sampled using a sequential ingrowth core method over 2 yr. After color categorization, roots were classified into protoxylem groups from anatomical observations. The root lengths with diarch and triarch groups fluctuated seasonally, whereas the tetrarch root length increased. The percentage of secondary root mortality to total mortality increased with increasing amounts of protoxylem. The carbon : nitrogen ratio indicated that the decomposability of primary roots might be greater than that of secondary roots. The position of diarch roots was mostly apical, whereas tetrarch roots tended to be distributed in basal positions within the root architecture. We demonstrate the heterogeneous dynamics within a fine-root system of C. obtusa. Fine-root heterogeneity should affect soil C dynamics. This heterogeneity is determined by the branching position within the root architecture.

  10. Meromorphic iterative roots of linear fractional functions

    Institute of Scientific and Technical Information of China (English)

    SHI YongGuo; CHEN Li

    2009-01-01

    Iterative root problem can be regarded as a weak version of the problem of embedding a homeomorphism into a flow. There are many results on iterative roots of monotone functions. However, this problem gets more difficult in non-monotone cases. Therefore, it is interesting to find iterative roots of linear fractional functions (abbreviated as LFFs), a class of non-monotone functions on R. In this paper, iterative roots of LFFs are studied on C. An equivalence between the iterative functional equation for non-constant LFFs and the matrix equation is given. By means of a method of finding matrix roots, general formulae of all meromorphic iterative roots of LFFs are obtained and the precise number of roots is also determined in various cases. As applications, we present all meromorphic iterative roots for functions z and 1/z.

  11. 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

    Full Text Available Abstract Background An accepted hypothesis states that coronary atherosclerosis (CA is initiated by endothelial dysfunction due to inflammation and high levels of LDL-C, followed by deposition of lipids and macrophages from the luminal blood into the arterial intima, resulting in plaque formation. The success of statins in preventing CA promised much for extended protection and effective therapeutics. However, stalled progress in pharmaceutical treatment gives a good reason to review logical properties of the hypothesis underlining our efforts, and to reconsider whether our perception of CA is consistent with facts about the normal and diseased coronary artery. Analysis To begin with, it must be noted that the normal coronary intima is not a single-layer endothelium covering a thin acellular compartment, as claimed in most publications, but always appears as a multi-layer cellular compartment, or diffuse intimal thickening (DIT, in which cells are arranged in many layers. If low density lipoprotein cholesterol (LDL-C invades the DIT from the coronary lumen, the initial depositions ought to be most proximal to blood, i.e. in the inner DIT. The facts show that the opposite is true, and lipids are initially deposited in the outer DIT. This contradiction is resolved by observing that the normal DIT is always avascular, receiving nutrients by diffusion from the lumen, whereas in CA the outer DIT is always neovascularized from adventitial vasa vasorum. The proteoglycan biglycan, confined to the outer DIT in both normal and diseased coronary arteries, has high binding capacity for LDL-C. However, the normal DIT is avascular and biglycan-LDL-C interactions are prevented by diffusion distance and LDL-C size (20 nm, whereas in CA, biglycan in the outer DIT can extract lipoproteins by direct contact with the blood. These facts lead to the single simplest explanation of all observations: (1 lipid deposition is initially localized in the outer DIT; (2 CA

  12. Single-rooted primary first mandibular molar

    OpenAIRE

    Haridoss, SelvaKumar; Swaminathan, Kavitha; Rajendran, Vijayakumar; Rajendran, Bharathan

    2014-01-01

    Morphological variations like single-rooted molar in primary dentition are scarce. Understanding the root canal anatomy and variations is necessary for successful root canal therapy. The purpose of the present article is to report successful endodontic treatment of primary left mandibular first molar with an abnormal morphology of a single root. This case report highlights the importance of knowledge and its applications in the management of anomalous anatomic variants which play a crucial ro...

  13. The rhizosphere revisited: root microbiomics

    Directory of Open Access Journals (Sweden)

    Peter A.H.M. Bakker

    2013-05-01

    Full Text Available The rhizosphere was defined over 100 years ago as the zone around the root where microorganisms and processes important for plant growth and health are located. Recent studies show that the diversity of microorganisms associated with the root system is enormous. This rhizosphere microbiome extends the functional repertoire of the plant beyond imagination. The rhizosphere microbiome of Arabidopsis thaliana is currently being studied for the obvious reason that it allows the use of the extensive toolbox that comes with this model plant. Deciphering plant traits that drive selection and activities of the microbiome is now a major challenge in which Arabidopsis will undoubtedly be a major research object. Here we review recent microbiome studies and discuss future research directions and applicability of the generated knowledge

  14. Automatic Schema Evolution in Root

    Institute of Scientific and Technical Information of China (English)

    ReneBrun; FonsRademakers

    2001-01-01

    ROOT version 3(spring 2001) supports automatic class schema evolution.In addition this version also produces files that are self-describing.This is achieved by storing in each file a record with the description of all the persistent classes in the file.Being self-describing guarantees that a file can always be read later,its structure browsed and objects inspected.also when the library with the compiled code of these classes is missing The schema evolution mechanism supports the frequent case when multiple data sets generated with many different class versions must be analyzed in the same session.ROOT supports the automatic generation of C++ code describing the data objects in a file.

  15. Doubling bialgebras of rooted trees

    Science.gov (United States)

    Mohamed, Mohamed Belhaj; Manchon, Dominique

    2017-01-01

    The vector space spanned by rooted forests admits two graded bialgebra structures. The first is defined by Connes and Kreimer using admissible cuts, and the second is defined by Calaque, Ebrahimi-Fard and the second author using contraction of trees. In this article, we define the doubling of these two spaces. We construct two bialgebra structures on these spaces which are in interaction, as well as two related associative products obtained by dualization. We also show that these two bialgebras verify a commutative diagram similar to the diagram verified Calaque, Ebrahimi-Fard and the second author in the case of rooted trees Hopf algebra, and by the second author in the case of cycle-free oriented graphs.

  16. Counting Rooted Nearly 2-regular Planar Maps

    Institute of Scientific and Technical Information of China (English)

    郝荣霞; 蔡俊亮

    2004-01-01

    The number of rooted nearly 2-regular maps with the valency of rootvertex, the number of non-rooted vertices and the valency of root-face as three parameters is obtained. Furthermore, the explicit expressions of the special cases including loopless nearly 2-regular maps and simple nearly 2-regular maps in terms of the above three parameters are derived.

  17. Facilitative root interactions in intercrops

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, H.; Jensen, E.S.

    2005-01-01

    Facilitation takes place when plants ameliorate the environment of their neighbours, and increase their growth and survival. Facilitation occurs in natural ecosystems as well as in agroecosystems. We discuss examples of facilitative root interactions in intercropped agroecosystems; including...... intensified cropping systems using chemical and mechanical inputs also show that facilitative interactions definitely can be of significance. It is concluded that a better understanding of the mechanisms behind facilitative interactions may allow us to benefit more from these phenomena in agriculture...

  18. Archimedes' calculations of square roots

    CERN Document Server

    Davies, E B

    2011-01-01

    We reconsider Archimedes' evaluations of several square roots in 'Measurement of a Circle'. We show that several methods proposed over the last century or so for his evaluations fail one or more criteria of plausibility. We also provide internal evidence that he probably used an interpolation technique. The conclusions are relevant to the precise calculations by which he obtained upper and lower bounds on pi.

  19. 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%.

  20. Evaluation of bacterial leakage of four root- end filling materials: Gray Pro Root MTA, White Pro Root MTA, Root MTA and Portland Cement (type I

    Directory of Open Access Journals (Sweden)

    Zarabian M.

    2005-07-01

    Full Text Available Background and Aim: Today several materials have been used for root- end filling in endodontic surgery. Optimal properties of Pro Root MTA in in-vitro and in-vivo studies has been proven. On the other hand, based on some studies, Root MTA (Iranian Pro Root MTA and Portland cement are similar to Pro Root MTA in physical and biologic properties. The aim of this study was to evaluate bacterial leakage (amount and mean leakage time of four root- end filling materials. Materials and Methods: In this experimental in-vitro study, seventy six extracted single- rooted human teeth were randomly divided into six groups for root-end filling with gray Pro Root MTA, white Pro Root MTA, Root MTA (Iranian Pro Root MTA, Portland Cement (type I and positive and negative control groups. Root canals were instrumented using the step- back technique. Root- end filling materials were placed in 3mm ultra sonic retro preparations. Samples and microleakage model system were sterilized in autoclave. The apical 3-4 mm of the roots were immersed in phenol red with 3% lactose broth culture medium. The coronal access of each specimen was inoculated every 24h with a suspension of Streptococcus sanguis (ATCC 10556. Culture media were observed every 24h for colour change indicating bacterial contamination for 60 days. Statistical analysis was performed using log- rank test with P<0.05 as the limit of significance. Results: At the end of study 50%, 56.25%, 56.25% and 50% of specimens filled with Gray Pro Root MTA, White Pro Root MTA. Root MTA and Portland Cement (type I had evidence of leakage respectively. The mean leakage time was 37.19±6.29, 36.44±5.81, 37.69±5.97 and 34.81±6.67 days respectively. Statistical analysis of data showed no significant difference among the leakage (amount and mean leakage time of the four tested root- end filling materials (P=0.9958. Conclusion: Based on the results of this study, there were no significant differences in leakage among the four

  1. Printing Values In Interactive ROOT

    CERN Document Server

    Perovic, Boris

    2015-01-01

    This project report summarizes the work I have been performing during the past twelve weeks as a Summer Student intern working on ROOT project in the SFT group, PH department, under the supervision of Axel Naumann and Danilo Piparo. One of the widely requested features for ROOT was improved interactive shell experience as well as improved printing of object values. Solving this issue was the goal of this project. Primarily, we have enabled printing of the collections. Secondly, we have unified the printing interface, making it much more robust and extendible. Thirdly, we have implemented printing of nested collections in a flexible and user-friendly manner. Finally, we have added an interactive mode, allowing for paginated output. At the beginning of the report, ROOT is presented with examples of where it is used and how important it is. Then, the motivation behind the project is elaborated, by presenting the previous state of the software package and its potential for improvement. Further, the process in wh...

  2. 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...

  3. Phene synergism between root hair length and basal root growth angle for phosphorus acquisition.

    Science.gov (United States)

    Miguel, Magalhaes Amade; Postma, Johannes Auke; Lynch, Jonathan Paul

    2015-04-01

    Shallow basal root growth angle (BRGA) increases phosphorus acquisition efficiency by enhancing topsoil foraging because in most soils, phosphorus is concentrated in the topsoil. Root hair length and density (RHL/D) increase phosphorus acquisition by expanding the soil volume subject to phosphorus depletion through diffusion. We hypothesized that shallow BRGA and large RHL/D are synergetic for phosphorus acquisition, meaning that their combined effect is greater than the sum of their individual effects. To evaluate this hypothesis, phosphorus acquisition in the field in Mozambique was compared among recombinant inbred lines of common bean (Phaseolus vulgaris) having four distinct root phenotypes: long root hairs and shallow basal roots, long root hairs and deep basal roots, short root hairs and shallow basal roots, and short root hairs and deep basal roots. The results revealed substantial synergism between BRGA and RHL/D. Compared with short-haired, deep-rooted phenotypes, long root hairs increased shoot biomass under phosphorus stress by 89%, while shallow roots increased shoot biomass by 58%. Genotypes with both long root hairs and shallow roots had 298% greater biomass accumulation than short-haired, deep-rooted phenotypes. Therefore, the utility of shallow basal roots and long root hairs for phosphorus acquisition in combination is twice as large as their additive effects. We conclude that the anatomical phene of long, dense root hairs and the architectural phene of shallower basal root growth are synergetic for phosphorus acquisition. Phene synergism may be common in plant biology and can have substantial importance for plant fitness, as shown here.

  4. The quality of root fillings remaining in mandibular incisors after root-end cavity preparation

    NARCIS (Netherlands)

    Wu, MK; de Schwartz, FBC; van der Sluis, LWM; Wesselink, PR

    2001-01-01

    Aim The aim of this study was to determine the quality of root fillings remaining in mandibular incisors after root-end resection and root-end cavity preparation. Methodology Roots of 40 mandibular incisors. 12 mm in length. were divided into two groups and instrumented using a balanced force techni

  5. 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...

  6. Light as stress factor to plant roots - case of root halotropism.

    Science.gov (United States)

    Yokawa, Ken; Fasano, Rossella; Kagenishi, Tomoko; Baluška, František

    2014-01-01

    Despite growing underground, largely in darkness, roots emerge to be very sensitive to light. Recently, several important papers have been published which reveal that plant roots not only express all known light receptors but also that their growth, physiology and adaptive stress responses are light-sensitive. In Arabidopsis, illumination of roots speeds-up root growth via reactive oxygen species-mediated and F-actin dependent process. On the other hand, keeping Arabidopsis roots in darkness alters F-actin distribution, polar localization of PIN proteins as well as polar transport of auxin. Several signaling components activated by phytohormones are overlapping with light-related signaling cascade. We demonstrated that the sensitivity of roots to salinity is altered in the light-grown Arabidopsis roots. Particularly, light-exposed roots are less effective in their salt-avoidance behavior known as root halotropism. Here we discuss these new aspects of light-mediated root behavior from cellular, physiological and evolutionary perspectives.

  7. Asteroidal Quadruples in non Rooted Path Graphs

    Directory of Open Access Journals (Sweden)

    Gutierrez Marisa

    2015-11-01

    Full Text Available A directed path graph is the intersection graph of a family of directed subpaths of a directed tree. A rooted path graph is the intersection graph of a family of directed subpaths of a rooted tree. Rooted path graphs are directed path graphs. Several characterizations are known for directed path graphs: one by forbidden induced subgraphs and one by forbidden asteroids. It is an open problem to find such characterizations for rooted path graphs. For this purpose, we are studying in this paper directed path graphs that are non rooted path graphs. We prove that such graphs always contain an asteroidal quadruple.

  8. 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...

  9. Penis-root perception of Koro patients.

    Science.gov (United States)

    Chowdhury, A N

    1991-07-01

    Koro is an acute anxiety reaction in which the perception of decreased penis length because of intra-abdominal traction is the main feature. This study attempts to explore the penis-root perception of the Koro patients by a graphomotor projective test--the Draw-a-penis Test (DAPT). This controlled DAPT investigation shows that Koro patients perceived the penis as a detached organ with root-boundary definiteness as evidenced from their close penis-root perception. They also displayed reduced volumetric perception of penis-root than the normal subjects. These perceptual deviations in penis-root image are discussed in relation to their Koro vulnerability.

  10. Popliteal Artery Adventitial Cyst: case report and literature review Cisto Adventicial de Artéria Poplítea: relato de caso e revisão da literatura

    Directory of Open Access Journals (Sweden)

    Angelo Frankini

    2012-06-01

    Full Text Available The popliteal artery adventitial cyst is not a commonly studied pathology due to the rarity of its occurrence, however it is a disease that should always be considered as a differential diagnosis in the presence of a young patient who complains of claudication of the lower limbs. Because of its importance, the aim of this paper is to review some concepts about this disease based on a case report, analyzing its occurrence, etiopathology, clinical manifestations, diagnosis and treatment options.O cisto adventicial de artéria poplítea é uma patologia pouco estudada na literatura devido à raridade de sua ocorrência, porém é uma situação que serve como diagnóstico diferencial sempre que estivermos diante de um paciente jovem com claudicação. Em virtude da sua importância, este trabalho tem como objetivo revisar alguns aspectos acerca do assunto, baseado em um relato de caso, analisando sua ocorrência, etiopatogenia, manifestações clínicas, métodos de diagnóstico e opções de tratamento.

  11. Use of PCR-based assays for the detection of the adventitious agent porcine circovirus type 1 (PCV1) in vaccines, and for confirming the identity of cell substrates and viruses used in vaccine production.

    Science.gov (United States)

    Kumar, Deepak; Beach, Nathan M; Meng, Xiang-Jin; Hegde, Nagendra R

    2012-01-01

    Safety and quality are important issues for vaccines. Whereas reversion to virulence poses a safety risk with live attenuated vaccines, the potential for the presence of adventitious agents is also an issue of vaccine quality. The recent detection or porcine circovirus type 1 (PCV1) in human vaccines has further highlighted the importance of quality control in vaccine production. The purpose of this study was to use a novel conventional PCR to detect PCV1, and subsequently screen materials used in the manufacture of vaccines at Bharat Biotech International Limited, India. The genome or gene fragments of PCV1 were not detected in any of the vaccines and materials tested, including the live attenuated rotavirus vaccine candidate ROTAVAC(®). Further, the identity of the cells and the viruses used as starting materials in the manufacture of these vaccines was confirmed by species-specific PCR or virus-specific RT-PCR, and no cross-contamination was detected in any case. The methods can be applied for regular in-house quality control screening of raw materials and seeds/banks, as well as formulated vaccines.

  12. Optimal root arrangement of cereal crops

    Science.gov (United States)

    Jung, Yeonsu; Park, Keunhwan; Kim, Ho-Young

    2015-11-01

    The plant root absorbs water from the soil and supplies it to the rest part of the plant. It consists of a number of root fibers, through whose surfaces water uptake occurs. There is an intriguing observation that for most of cereal crops such as maize and wheat, the volume density of root in the soil declines exponentially as a function of depth. To understand this empirical finding, we construct a theoretical model of root water uptake, where mass transfer into root surface is modeled just as heat flux around a fin. Agreement between the theoretically predicted optimal root distribution in vertical direction and biological data supports the hypothesis that the plant root has evolved to achieve the optimal water uptake in competition with neighbors. This study has practical implication in the agricultural industry as well as optimal design of water transport networks in both micro- and macroscales. Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 08826, Korea.

  13. 苦荞麦毛状根的诱导研究%Study on Hairy-roots Induction of Fagopyrum tataricum Gaertn

    Institute of Scientific and Technical Information of China (English)

    孙雁霞; 王跃华; 陈燕; 张红玉; 赵钢; 邬晓勇

    2012-01-01

    利用发根农杆菌Ri1601浸染苦养植物预培养2d的叶片外植体,经不同时间的共培养和除菌培养后获得毛状根.经硅胶薄层色谱板检测表明,发根农杆菌Ri1601和苦养叶片上未经转化产生的不定根都不含有冠瘿碱;而经发根农杆菌Ri1601遗传转化后所产生的毛状根有冠瘿碱的存在.因此,可确定苦荞叶片上产生的毛状根为发根农杆菌Ri1601转化所得.建立了用发根农杆菌Ri1601诱导苦荞植物叶片产生毛状根的有效方法.%The Hairy-roots can be obtained by inoculating two-day-precultured leaf explants of Fagopyrum tataricum Gaertn with Agrobaterium rhizogenes Ril601. The silicon thin layer chromatogra-phy (TLC) tests showed that the adventitious roots produced by leaves of Fagopyrum tataricum Gaertn and Agrobaterium rhizogenes Ril601 do not contain crown gall alkali. On the other hand, the hairy roots which were produced by Agrobaterium rhizogenes Ril601-mediated genetic transformation of Fagopyrum tataricum Gaertn leaves have crown gall alkali. Therefore, it can be determined that the hairy roots from leaves of Fagopyrum tataricum Gaertn were produced by Agrobaterium rhizogenes Ril601-mediated transformation. Due to these, the different factors were designed to examine for their effects on hairy-roots induction and growth. The effective methodology of hairy-roots induction by Agrobaterium rhizogenes was established and provided a foundation for industrial production of active components from Fagopyrum tataricum Gaertn.

  14. Effects of fine root length density and root biomass on soil preferential flow in forest ecosystems

    Directory of Open Access Journals (Sweden)

    Yinghu Zhang

    2015-04-01

    Full Text Available Aim of study: The study was conducted to characterize the impacts of plant roots systems (e.g., root length density and root biomass on soil preferential flow in forest ecosystems. Area of study: The study was carried out in Jiufeng National Forest Park, Beijing, China. Material and methods: The flow patterns were measured by field dye tracing experiments. Different species (Sophora japonica Linn,Platycladus orientalis Franco, Quercus dentata Thunbwere quantified in two replicates, and 12 soil depth were applied. Plant roots were sampled in the sieving methods. Root length density and root biomass were measured by WinRHIZO. Dye coverage was implied in the image analysis, and maximum depth of dye infiltration by direct measurement. Main results: Root length density and root biomass decreased with the increasing distance from soil surface, and root length density was 81.6% higher in preferential pathways than in soil matrix, and 66.7% for root biomass with respect to all experimental plots. Plant roots were densely distributed in the upper soil layers. Dye coverage was almost 100% in the upper 5-10 cm, but then decreased rapidly with soil depth. Root length density and root biomass were different from species: Platycladus orientalis Franco > Quercus dentata Thunb > Sophora japonica Linn. Research highlights: The results indicated that fine roots systems had strong effects on soil preferential flow, particularly root channels enhancing nutrition transport across soil profiles in forest dynamics.

  15. Root cap removal increases root penetration resistance in maize (Zea mays L).

    Science.gov (United States)

    Iijima, Morio; Higuchi, Toshifumi; Barlow, Peter W; Bengough, A Glyn

    2003-09-01

    The root cap assists the passage of the root through soil by means of its slimy mucilage secretion and by the sloughing of its outer cells. The root penetration resistance of decapped primary roots of maize (Zea mays L. cv. Mephisto) was compared with that of intact roots in loose (dry bulk density 1.0 g cm-3; penetration resistance 0.06 MPa) and compact soil (1.4 g cm-3; penetration resistance 1.0 MPa), to evaluate the contribution of the cap to decreasing the impedance to root growth. Root elongation rate and diameter were the same for decapped and intact roots when the plants were grown in loose soil. In compacted soil, however, the elongation rate of decapped roots was only about half that of intact roots, whilst the diameter was 30% larger. Root penetration resistances of intact and decapped seminal axis were 0.31 and 0.52 MPa, respectively, when the roots were grown in compacted soil. These results indicated that the presence of a root cap alleviates much of the mechanical impedance to root penetration, and enables roots to grow faster in compacted soils.

  16. Hydraulic responses of whole vines and individual roots of kiwifruit (Actinidia chinensis) following root severance.

    Science.gov (United States)

    Black, Marykate Z; Patterson, Kevin J; Minchin, Peter E H; Gould, Kevin S; Clearwater, Michael J

    2011-05-01

    Whole vine (K(plant)) and individual root (K(root)) hydraulic conductances were measured in kiwifruit (Actinidia chinensis Planch. var. chinensis 'Hort16A') vines to observe hydraulic responses following partial root system excision. Heat dissipation and compensation heat pulse techniques were used to measure sap flow in trunks and individual roots, respectively. Sap flux and measurements of xylem pressure potential (Ψ) were used to calculate K(plant) and K(root) in vines with zero and ∼80% of roots severed. Whole vine transpiration (E), Ψ and K(plant) were significantly reduced within 24 h of root pruning, and did not recover within 6 weeks. Sap flux in intact roots increased within 24 h of root pruning, driven by an increase in the pressure gradient between the soil and canopy and without any change in root hydraulic conductance. Photosynthesis (A) and stomatal conductance (g(s)) were reduced, without significant effects on leaf internal CO(2) concentration (c(i)). Shoot growth rates were maintained; fruit growth and dry matter content were increased following pruning. The woody roots of kiwifruit did not demonstrate a rapid dynamic response to root system damage as has been observed previously in monocot seedlings. Increased sap flux in intact roots with no change in K(root) and only a moderate decline in shoot A suggests that under normal growing conditions root hydraulic conductance greatly exceeds requirements for adequate shoot hydration.

  17. Patterns in soil fertility and root herbivory interact to influence fine-root dynamics.

    Science.gov (United States)

    Stevens, Glen N; Jones, Robert H

    2006-03-01

    Fine-scale soil nutrient enrichment typically stimulates root growth, but it may also increase root herbivory, resulting in trade-offs for plant species and potentially influencing carbon cycling patterns. We used root ingrowth cores to investigate the effects of microsite fertility and root herbivory on root biomass in an aggrading upland forest in the coastal plain of South Carolina, USA. Treatments were randomly assigned to cores from a factorial combination of fertilizer and insecticide. Soil, soil fauna, and roots were removed from the cores at the end of the experiment (8-9 mo), and roots were separated at harvest into three diameter classes. Each diameter class responded differently to fertilizer and insecticide treatments. The finest roots (root biomass, were the only ones to respond significantly to both treatments, increasing when fertilizer and when insecticide were added (each P root-feeding insects have a strong influence on root standing crop with stronger herbivore impacts on finer roots and within more fertile microsites. Thus, increased vulnerability to root herbivory is a potentially significant cost of root foraging in nutrient-rich patches.

  18. 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.

  19. A statistical approach to root system classification.

    Directory of Open Access Journals (Sweden)

    Gernot eBodner

    2013-08-01

    Full Text Available Plant root systems have a key role in ecology and agronomy. In spite of fast increase in root studies, still there is no classification that allows distinguishing among distinctive characteristics within the diversity of rooting strategies. Our hypothesis is that a multivariate approach for plant functional type identification in ecology can be applied to the classification of root systems. We demonstrate that combining principal component and cluster analysis yields a meaningful classification of rooting types based on morphological traits. The classification method presented is based on a data-defined statistical procedure without a priori decision on the classifiers. Biplot inspection is used to determine key traits and to ensure stability in cluster based grouping. The classification method is exemplified with simulated root architectures and morphological field data. Simulated root architectures showed that morphological attributes with spatial distribution parameters capture most distinctive features within root system diversity. While developmental type (tap vs. shoot-borne systems is a strong, but coarse classifier, topological traits provide the most detailed differentiation among distinctive groups. Adequacy of commonly available morphologic traits for classification is supported by field data. Three rooting types emerged from measured data, distinguished by diameter/weight, density and spatial distribution respectively. Similarity of root systems within distinctive groups was the joint result of phylogenetic relation and environmental as well as human selection pressure. We concluded that the data-define classification is appropriate for integration of knowledge obtained with different root measurement methods and at various scales. Currently root morphology is the most promising basis for classification due to widely used common measurement protocols. To capture details of root diversity efforts in architectural measurement

  20. A statistical approach to root system classification.

    Science.gov (United States)

    Bodner, Gernot; Leitner, Daniel; Nakhforoosh, Alireza; Sobotik, Monika; Moder, Karl; Kaul, Hans-Peter

    2013-01-01

    Plant root systems have a key role in ecology and agronomy. In spite of fast increase in root studies, still there is no classification that allows distinguishing among distinctive characteristics within the diversity of rooting strategies. Our hypothesis is that a multivariate approach for "plant functional type" identification in ecology can be applied to the classification of root systems. The classification method presented is based on a data-defined statistical procedure without a priori decision on the classifiers. The study demonstrates that principal component based rooting types provide efficient and meaningful multi-trait classifiers. The classification method is exemplified with simulated root architectures and morphological field data. Simulated root architectures showed that morphological attributes with spatial distribution parameters capture most distinctive features within root system diversity. While developmental type (tap vs. shoot-borne systems) is a strong, but coarse classifier, topological traits provide the most detailed differentiation among distinctive groups. Adequacy of commonly available morphologic traits for classification is supported by field data. Rooting types emerging from measured data, mainly distinguished by diameter/weight and density dominated types. Similarity of root systems within distinctive groups was the joint result of phylogenetic relation and environmental as well as human selection pressure. We concluded that the data-define classification is appropriate for integration of knowledge obtained with different root measurement methods and at various scales. Currently root morphology is the most promising basis for classification due to widely used common measurement protocols. To capture details of root diversity efforts in architectural measurement techniques are essential.

  1. Towards understanding tree root profiles: simulating hydrologically optimal strategies for root distribution

    Directory of Open Access Journals (Sweden)

    M. T. van Wijk

    2001-01-01

    Full Text Available In this modelling study differences in vertical root distributions measured in four contrasting forest locations in the Netherlands were investigated. Root distributions are seen as a reflection of the plant’s optimisation strategy, based on hydrological grounds. The 'optimal' root distribution is defined as the one that maximises the water uptake from the root zone over a period of ten years. The optimal root distributions of four forest locations with completely different soil physical characteristics are calculated using the soil hydrological model SWIF. Two different model configurations for root interactions were tested: the standard model configuration in which one single root profile was used (SWIF-NC, and a model configuration in which two root profiles compete for the same available water (SWIF-C. The root profiles were parameterised with genetic algorithms. The fitness of a certain root profile was defined as the amount of water uptake over a simulation period of ten years. The root profiles of SWIF-C were optimised using an evolutionary game. The results showed clear differences in optimal root distributions between the various sites and also between the two model configurations. Optimisation with SWIF-C resulted in root profiles that were easier to interpret in terms of feasible biological strategies. Preferential water uptake in wetter soil regions was an important factor for interpretation of the simulated root distributions. As the optimised root profiles still showed differences with measured profiles, this analysis is presented, not as the final solution for explaining differences in root profiles of vegetation but as a first step using an optimisation theory to increase understanding of the root profiles of trees. Keywords: forest hydrology, optimisation, roots

  2. Root canal treatment of bilateral three-rooted maxillary first premolars

    Directory of Open Access Journals (Sweden)

    Bhavana Gandhi

    2012-01-01

    Full Text Available In endodontics, several anatomic variations occur in teeth, both externally and in the internal root morphology, which play a very significant role in the diagnosis and treatment outcome. A thorough knowledge of the root canal anatomy, careful interpretation of the angled radiographs, proper endodontic access cavity preparation, and exploration of the root canal are the prerequisites for endodontic success. In a maxillary first premolar, it is rare to find extra roots and canals, and the aim of the present article is to report a case about the successful diagnosis and clinical management of bilateral three-rooted maxillary first premolars, with three independent root canals.

  3. Winter Wheat Root Growth and Nitrogen Relations

    DEFF Research Database (Denmark)

    Rasmussen, Irene Skovby

    Root growth is an essential parameter regarding nitrogen (N) uptake efficiency, as more and deeper roots may improve the uptake from deeper soil layers and reduce nitrate leaching losses. During this PhD project, it was studied how different agronomic practices influence root growth and N relations...... in winter wheat (Triticum aestivum L). Field experiments on the effect of sowing date, N fertilization and cultivars were conducted on a sandy loam soil in Taastrup, Denmark. The root studies were conducted by means of the minirhizotron method. Also, a field experiment on the effect of defoliation and N...... fertilization was conducted in Canberra, Australia. Here the root studies were done by means of the core-break method and root washing....

  4. 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.

  5. INDUSTRIAL ENGINEERING : ROOTING FOR ROOTS, HANKERING FOR HEROES

    Directory of Open Access Journals (Sweden)

    P.S. Kruger

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: The “roots” of Industrial Engineering are certainly extensive, diverse and deep. Similarly, there are numerous historical “heroes” that made significant contributions to the development of the Industrial Engineering discipline. For the sake of argument, this article will assume that Industrial Engineering has at least two identifiable main roots, namely Determinism and Stochastism. The article attempts to trace the early history1 of the stochastic root which is very closely linked to the history of probability and statistics and hence games of chance, gambling and divinity. Therefore, the life and times, contributions and personalities of some of the heroes and villains, champions and sad cases of the stochastic world, will be briefly discussed in a somewhat light-hearted, but not necessarily flippant, manner.

    AFRIKAANSE OPSOMMING: Die “wortel en tak” van Bedryfsingenieurswese is sekerlik van groot omvang, van diverse aard en diep gesetel. Verskeie historiese “helde” het betekenisvolle bydraes gemaak tot die ontwikkeling van die Bedryfsingenieurswesevakgebied. Ter wille van betoogvoering sal in hierdie artikel aanvaar word dat Bedryfsingenieurswese uit minstens twee identifiseerbare sub-vakgebiede bestaan naamlik : Die Determinisme en die Stogasme. ’n Poging word aangewend om die vroeë geskiedenis van die stogasme na te speur wat op sy beurt aaneengesnoer is met die geskiedenis van die waarskynlikheidsleer en statistiek en dus toevalspelle, dobbelary en wiggelary. Die lewenswyse, tydsgewrig, bydraes en persoonlikheidseienskappe van ’n aantal helde en skurke, kampioene en prulle van die stogastiese wêreld word kortliks bespreek, op ’n ietwat lighartige maar nie noodwendig ligsinnige wyse.

  6. Rooting of cuttings of vanilla plant (Orchidaceae / Enraizamento de estacas da baunilheira (Orchidaceae

    Directory of Open Access Journals (Sweden)

    Aparecida Gomes de Araujo

    2009-07-01

    Full Text Available The vanilla plant (Vanilla planifolia could have a higher commercial production but there are problems in the efficiency of propagation. The present work was conducted with the aim of studying the effect of different substrates, in the adventitious rooting of cuttings taken at five heights in the plant stem. The cuttings were 20cm long and had two buds and one leaf and were planted in: 1 Liquid medium formed by Clark’s nutrient added of 2.5mg L-1 of IBA placed in plastic foam box with a capacity of 1.5L lined inside with transparent plastic bag and lidded with proper lid. 2 Solid substrate formed by the mixture of sand, carbonized rice husk, soil and cured cow manure in equal proportions of volume, they being placed in rigid polypropylene with a capacity of 0.28L. 3 Pre-rooting of the cuttings in liquid medium (20 days before planting, and later transferred into seedling tubes containing solid substrate. The cuttings planted in the solid substrate were maintained under intermittent mist condition controlled by a timer. After 90 days, the percentage of rooting was of 98-100%, regardless of the treatment. Larger and more vigorous sproutings were obtained from cuttings planted directly into solid substrate. Adventitious rooting of cuttings and formation of new vanilla cuttings occurred, when the cuttings were obtained from position P2 (ranging between 20 to 40cm in stem height and planted in solid substrate in greenhouse with intermittent misting system. A baunilheira (Vanilla planifolia é uma planta pouco explorada comercialmente, devido ao emprego de tecnologias de baixa eficiência para a produção de mudas. Assim sendo, realizou-se o presente trabalho com o objetivo de estudar o efeito de diferentes substratos, no enraizamento adventício de estacas retiradas de diferentes posições na planta. Estacas com 20cm de comprimento, duas gemas e uma folha, tomadas na haste da planta, em cinco posições subseqüentes, a partir do ápice caulinar

  7. Root phenology in a changing climate.

    Science.gov (United States)

    Radville, Laura; McCormack, M Luke; Post, Eric; Eissenstat, David M

    2016-06-01

    Plant phenology is one of the strongest indicators of ecological responses to climate change, and altered phenology can have pronounced effects on net primary production, species composition in local communities, greenhouse gas fluxes, and ecosystem processes. Although many studies have shown that aboveground plant phenology advances with warmer temperatures, demonstration of a comparable association for belowground phenology has been lacking because the factors that influence root phenology are poorly understood. Because roots can constitute a large fraction of plant biomass, and root phenology may not respond to warming in the same way as shoots, this represents an important knowledge gap in our understanding of how climate change will influence phenology and plant performance. We review studies of root phenology and provide suggestions to direct future research. Only 29% of examined studies approached root phenology quantitatively, strongly limiting interpretation of results across studies. Therefore, we suggest that researchers emphasize quantitative analyses in future phenological studies. We suggest that root initiation, peak growth, and root cessation may be under different controls. Root initiation and cessation may be more constrained by soil temperature and the timing of carbon availability, whereas the timing of peak root growth may represent trade-offs among competing plant sinks. Roots probably do not experience winter dormancy in the same way as shoots: 89% of the studies that examined winter phenology found evidence of growth during winter months. More research is needed to observe root phenology, and future studies should be careful to capture winter and early season phenology. This should be done quantitatively, with direct observations of root growth utilizing rhizotrons or minirhizotrons.

  8. Designing new interfaces for ROOT data processing

    CERN Document Server

    Vuorinen, Kalle Elmer

    2016-01-01

    ROOT is a C++ framework for data analysis provided with a Python interface (PyRoot). ROOT is used in every Large Hadron Collider experiment. This project presents a way of reading ROOT TTree by using a new class called DataFrame, which allows the usage of cache and functional chains. Reading TTrees in Python has been quite slow compared to the C++ way of doing it and for this reason we also bring the possibility to read them with just-in-time (JIT) compiled C++ code, using another new Python class called TreeReader.

  9. Mandibular second premolar with four roots

    Directory of Open Access Journals (Sweden)

    Sefika Nur Akyuz

    2012-01-01

    Full Text Available Detection of normal and abnormal variation in tooth anatomy is essential for clinical success. It is generally well known that the mandibular second premolar teeth have a single root and canal. However, the mandibular second premolar teeth have sometimes more than one root and root canal. The endodontic treatment of a mandibular second premolar with four roots which separated at different levels along the middle third of the root is presented in this case report. Preoperative radiographs appeared radiolucency and different root anatomy in the region of the mandibular second premolar. The root canals were prepared using Mtwo rotary system (VDW, Munich, Germany and obturated laterally condensed gutta percha and AH plus (Dentsply De Trey, Konstanz, Germany. After the completion of root canal treatment, the tooth was restored with a posterior composite filling material. On follow-up, the tooth was clinically and radiographically asymptomatic for two years. Clinicians should be aware of the importance of careful clinical and radiographic examination of mandibular premolars during the endodontic treatment. Radiographs exposed at two different horizontal angles and their careful interpretation facilitates the search of additional root canals.

  10. Power Efficient Division and Square Root Unit

    DEFF Research Database (Denmark)

    Liu, Wei; Nannarelli, Alberto

    2012-01-01

    shows that division and square root units based on the digit-recurrence algorithm offer the best tradeoff delay-area-power. Moreover, the two operations can be combined in a single unit. Here, we present a radix-16 combined division and square root unit obtained by overlapping two radix-4 stages......Although division and square root are not frequent operations, most processors implement them in hardware to not compromise the overall performance. Two classes of algorithms implement division or square root: digit-recurrence and multiplicative (e.g., Newton-Raphson) algorithms. Previous work...

  11. 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

  12. ROOT HYDRAULIC CONDUCTIVITY AND PHOTOSYNTHETIC CAPACITY OF EUCALYPT CLONAL CUTTINGS WITH ROOT MALFORMATION INDUCTIONS

    Directory of Open Access Journals (Sweden)

    Fábio Afonso Mazzei Moura de Assis Figueiredo

    2014-06-01

    Full Text Available http://dx.doi.org/10.5902/1980509814566The gain reduction of wood biomass in trees has been assigned to root deformations even in the nursery phase. The objective of this work was the evaluation of the root system hydraulic conductivity, gas exchanges and photochemical efficiency of eucalypt clonal cuttings with and without root deformation inductions. The treatments were: 1 operational cuttings without root malformation inductions (grown according to the used methodology of Fibria Cellulose S.A.; 2 root deformation inductions. These inductions did not promote decrease in the root volume. However, the deformations brought reduction of the root system hydraulic conductivity. Lower photosynthetic rates were also observed along the day in the cuttings in the root deformed cuttings. This decreasing rate is connected to stomatal and non stomatal factors.

  13. Variations of fine root diameter with root order in Manchurian ash and Dahurian larch plantations

    Institute of Scientific and Technical Information of China (English)

    WANG Xiangrong; WANG Zhengquan; HAN Youzhi; GU Jiacun; GUO Dali; MEI Li

    2007-01-01

    Fine root lifespan and turnover play an important role in carbon allocation and nutrient cycling in forest ecosystems.Fine roots are typically defined as less than 1 or 2mm in diameter.However,when categorizing roots by this diameter size,the position of an individual root on the complex lateral branching pattern has often been ignored,and our knowledge about relationships between branching order and root function thus remains limited.More recently,studies on root survivals found that longevity was remarkably different in the same branching level due to diameter variations.The objectives of this study were:(1) To examine variations of fine root diameter from the first-to fifth-orders in Fraxinus mandshurica Rupr and Larix gmelinii Rupr roots;and (2) To reveal how the season,soil nutrient,and water availability affect root diameter in different branch order in two species.This study was conducted at Maoershan Forest Research Station (45°21'-45°25'N,127°30'-127°34'E) owned by Northeast Forestry University in Harbin,northeast China.Both F.mandshurica and L.gmelinii were planted in 1986.In each plantation,fine roots of two species by sampling up to five fine root branch orders three times during the 2003 growing season from two soil depths (i.e.,0-10 and 10-20 cm)were obtained.The results showed that average diameters of fine roots were significantly different among the five branch orders.The first-order had the thinner roots and the fifth order had the thickest roots,the diameter increasing regularly with the ascending branch orders in both species.If the diameter of fine roots was defined as being smaller than 0.5 mm,the first three orders ofF.mandshurica roots and the first two orders of L.gmelinii roots would be included in the fine root population.The diameter ranges of the fine roots from first-order to fifth-order were 0.15-0.58,0.18-0.70,0.26-1.05,0.36-1.43,and 0.71-2.96 mm for F.mandshurica,and 0.17-0.76,0.23-1.02,0.26-1.10,0.38-1.77,and 0.84-2.80 mm for L

  14. Anatomical evaluation of the root canal diameter and root thickness on the apical third of mesial roots of molars.

    Science.gov (United States)

    Martos, Josué; Tatsch, Gustavo Henrique; Tatsch, Augusto César; Silveira, Luiz Fernando Machado; Ferrer-Luque, Carmen María

    2011-09-01

    The purpose was to determine the diameter of the main root canal and wall thickness in the apical dentin in mesial roots of maxillary and mandibular molars. Forty mesiobuccal and mesial root specimens were sectioned horizontally at 1, 2 and 3 mm from the apex, and measured at each top surface by using optical microscopy to an accuracy of ×20 magnification. The anatomical parameters were established as the following points of reference: AB, two points connected by a line from the outer edge of the mesial wall to the outer edge of the distal one through the center of the root canal to measure the thickness of the root and mesiodistal diameter of the root canal (CD). A second line (EF) was designed to evaluate the diameter of the root canal in the buccolingual direction. All data were summarized, and values were assessed statistically by ANOVA and Bonferroni multiple comparisons. The buccolingual (BL) root canal diameters at 1, 2 and 3 mm in the mandibular and maxillary molars were greater than in the mesiodistal (MD), showing statistically significant differences (p maxillary molars were statistically significant (p maxillary molars was 1.741 mm. The BL diameters in maxillary and mandibular molars were higher than the MD diameter. The thickness (MD) of maxillary and mandibular molars decreased as a function of apical proximity.

  15. Piriformospora indica root colonization triggers local and systemic root responses and inhibits secondary colonization of distal roots.

    Directory of Open Access Journals (Sweden)

    Lorenzo Pedrotti

    Full Text Available Piriformosporaindica is a basidiomycete fungus colonizing roots of a wide range of higher plants, including crop plants and the model plant Arabidopsis thaliana. Previous studies have shown that P. indica improves growth, and enhances systemic pathogen resistance in leaves of host plants. To investigate systemic effects within the root system, we established a hydroponic split-root cultivation system for Arabidopsis. Using quantitative real-time PCR, we show that initial P. indica colonization triggers a local, transient response of several defense-related transcripts, of which some were also induced in shoots and in distal, non-colonized roots of the same plant. Systemic effects on distal roots included the inhibition of secondary P. indica colonization. Faster and stronger induction of defense-related transcripts during secondary inoculation revealed that a P. indica pretreatment triggers root-wide priming of defense responses, which could cause the observed reduction of secondary colonization levels. Secondary P. indica colonization also induced defense responses in distant, already colonized parts of the root. Endophytic fungi therefore trigger a spatially specific response in directly colonized and in systemic root tissues of host plants.

  16. 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

  17. 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...

  18. 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

  19. 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

  20. Fine root production at drained peatland sites

    Energy Technology Data Exchange (ETDEWEB)

    Finer, L. [Finnish Forest Research Inst. (Finland). Joensuu Research Station; Laine, J. [Helsinki Univ. (Finland). Dept. of Forest Ecology

    1996-12-31

    The preliminary results of the Finnish project `Carbon balance of peatlands and climate change` show that fine roots play an important role in carbon cycling on peat soils. After drainage the roots of mire species are gradually replaced by the roots of trees and other forest species. Pine fine root biomass reaches a maximum level by the time of crown closure, some 20 years after drainage on pine mire. The aim of this study is to compare the results of the sequential coring method and the ingrowth bag method used for estimating fine root production on three drained peatland sites of different fertility. The results are preliminary and continuation to the work done in the study Pine root production on drained peatlands, which is part of the Finnish project `Carbon cycling on peatlands and climate change`. In this study the fine root biomass was greater on the poor site than on the rich sites. Pine fine root production increased with the decrease in fertility. Root turnover and the production of field layer species were greater on the rich sites than on the poor site. The results suggested that the in growth bag method measured more root activity than the magnitude of production. More than two growing seasons would have been needed to balance the root dynamics in the in growth bags with the surrounding soil. That time would probably have been longer on the poor site than on the rich ones and longer for pine and field layer consisting of dwarf shrubs than for field layer consisting of sedge like species and birch. (11 refs.)

  1. 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.

  2. Assessment of the nonoperated root after apical surgery of the other root in mandibular molars

    DEFF Research Database (Denmark)

    Kraus, Riccardo D; von Arx, Thomas; Gfeller, David

    2015-01-01

    INTRODUCTION: If a surgical approach is chosen to treat a multirooted tooth affected by persistent periapical pathosis, usually only the affected roots are operated on. The present study assessed the periapical status of the nonoperated root 5 years after apical surgery of the other root in mandi...

  3. Changes of Root Length and Root-to-Crown Ratio after Apical Surgery

    DEFF Research Database (Denmark)

    von Arx, Thomas; Jensen, Simon S; Bornstein, Michael M

    2015-01-01

    INTRODUCTION: Apical surgery is an important treatment option for teeth with post-treatment periodontitis. Although apical surgery involves root-end resection, no morphometric data are yet available about root-end resection and its impact on the root-to-crown ratio (RCR). The present study assess...

  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. On König's root finding algorithms

    DEFF Research Database (Denmark)

    Buff, Xavier; Henriksen, Christian

    2003-01-01

    In this paper, we first recall the definition of a family of root-finding algorithms known as König's algorithms. We establish some local and some global properties of those algorithms. We give a characterization of rational maps which arise as König's methods of polynomials with simple roots. We...

  6. Layers of root nouns in Germanic

    DEFF Research Database (Denmark)

    Hansen, Bjarne Simmelkjær Sandgaard

    2015-01-01

    The root-noun declension became productive in early Germanic, containing (I) inherited root nouns, (IIa) original substrate or loan words, and transitions from other declensions in (IIb) Proto-Germanic and (III) North Germanic. As ablaut was abolished, the inherited type would display ablaut grad...

  7. 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

  8. Graphing Powers and Roots of Complex Numbers.

    Science.gov (United States)

    Embse, Charles Vonder

    1993-01-01

    Using De Moivre's theorem and a parametric graphing utility, examines powers and roots of complex numbers and allows students to establish connections between the visual and numerical representations of complex numbers. Provides a program to numerically verify the roots of complex numbers. (MDH)

  9. 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.

  10. Rapid phenotyping of alfalfa root system architecture

    Science.gov (United States)

    Root system architecture (RSA) influences the capacity of an alfalfa plant for symbiotic nitrogen fixation, nutrient uptake and water use efficiency, resistance to frost heaving, winterhardiness, and some pest and pathogen resistance. However, we currently lack a basic understanding of root system d...

  11. Salt stress signals shape the plant root

    NARCIS (Netherlands)

    C.S. Galvan-Ampudia; C. Testerink

    2011-01-01

    Plants use different strategies to deal with high soil salinity. One strategy is activation of pathways that allow the plant to export or compartmentalise salt. Relying on their phenotypic plasticity, plants can also adjust their root system architecture (RSA) and the direction of root growth to avo

  12. Tissue engineering in endodontics: root canal revascularization.

    Science.gov (United States)

    Palit Madhu Chanda; Hegde, K Sundeep; Bhat, Sham S; Sargod, Sharan S; Mantha, Somasundar; Chattopadhyay, Sayan

    2014-01-01

    Root canal revascularization attempts to make necrotic tooth alive by the use of certain simple clinical protocols. Earlier apexification was the treatment of choice for treating and preserving immature permanent teeth that have lost pulp vitality. This procedure promoted the formation of apical barrier to seal the root canal of immature teeth and nonvital filling materials contained within root canal space. However with the success of root canal revascularization to regenerate the pulp dentin complex of necrotic immature tooth has made us to rethink if apexification is at the beginning of its end. The objective of this review is to discuss the new concepts of tissue engineering in endodontics and the clinical steps of root canal revascularization.

  13. 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.

  14. The Complexity of Rooted Phylogeny Problems

    CERN Document Server

    Bodirsky, Manuel

    2011-01-01

    Several computational problems in phylogenetic reconstruction can be formulated as restrictions of the following general problem: given a formula in conjunctive normal form where the literals are rooted triples, is there a rooted binary tree that satisfies the formula? If the formulas do not contain disjunctions, the problem becomes the famous rooted triple consistency problem, which can be solved in polynomial time by an algorithm of Aho, Sagiv, Szymanski, and Ullman. If the clauses in the formulas are restricted to disjunctions of negated triples, Ng, Steel, and Wormald showed that the problem remains NP-complete. We systematically study the computational complexity of the problem for all such restrictions of the clauses in the input formula. For certain restricted disjunctions of triples we present an algorithm that has sub-quadratic running time and is asymptotically as fast as the fastest known algorithm for the rooted triple consistency problem. We also show that any restriction of the general rooted ph...

  15. Clinical management of infected root canal dentin.

    Science.gov (United States)

    Love, R M

    1996-08-01

    Several hundred different species of bacteria are present in the human intraoral environment. Bacterial penetration of root canal dentin occurs when bacteria invade the root canal system. These bacteria may constitute a reservoir from which root canal reinfection may occur during or after endodontic treatment. The learning objective of this article is to review endodontic microbiology, update readers on the role of bacteria in pulp and periapical disease, and discuss the principles of management of infected root canal dentin. Complete debridement, removal of microorganisms and affected dentin, and chemomechanical cleansing of the root canal are suggested as being the cornerstones of successful endodontic therapy, followed by intracanal medication to remove residual bacteria, when required.

  16. 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.

  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. Root cap influences root colonisation by Pseudomonas fluorescens SBW25 on maize.

    Science.gov (United States)

    Humphris, Sonia N; Bengough, A Glyn; Griffiths, Bryan S; Kilham, Ken; Rodger, Sheena; Stubbs, Vicky; Valentine, Tracy A; Young, Iain M

    2005-09-01

    We investigated the influence of root border cells on the colonisation of seedling Zea mays roots by Pseudomonas fluorescens SBW25 in sandy loam soil packed at two dry bulk densities. Numbers of colony forming units (CFU) were counted on sequential sections of root for intact and decapped inoculated roots grown in loose (1.0 mg m(-3)) and compacted (1.3 mg m(-3)) soil. After two days of root growth, the numbers of P. fluorescens (CFU cm(-1)) were highest on the section of root just below the seed with progressively fewer bacteria near the tip, irrespective of density. The decapped roots had significantly more colonies of P. fluorescens at the tip compared with the intact roots: approximately 100-fold more in the loose and 30-fold more in the compact soil. In addition, confocal images of the root tips grown in agar showed that P. fluorescens could only be detected on the tips of the decapped roots. These results indicated that border cells, and their associated mucilage, prevented complete colonization of the root tip by the biocontrol agent P. fluorescens, possibly by acting as a disposable surface or sheath around the cap.

  19. Aerenchyma Formed Under Phosphorus Deficiency Contributes to the Reduced Root Hydraulic Conductivity in Maize Roots

    Institute of Scientific and Technical Information of China (English)

    Mingshou Fan; Ruiqin Bai; Xuefeng Zhao; Jianhua Zhang

    2007-01-01

    Root hydraulic conductivity has been shown to decrease under phosphorus (P) deficiency. This study investigated how the formation of aerenchyma is related to this change. Root anatomy, as well as root hydraulic conductivity was studied in maize (Zea mays L.) roots under different phosphorus nutrition conditions. Plant roots under P stress showed enhanced degradation of cortical cells and the aerenchyma formation was associated with their reduced root hydraulic conductivity, supporting our hypothesis that air spaces that form in the cortex of phosphorusstressed roots impede the radial transport of water in a root cylinder. Further evidence came from the variation in aerenchyma formation due to genotypic differences. Five maize inbred lines with different porosity in their root cortex showed a significant negative correlation with their root hydraulic conductivity. Shoot relative water content was also found lower in P-deficient maize plants than that in P-sufficient ones when such treatment was prolonged enough, suggesting a limitation of water transport due to lowered root hydraulic conductivity of P-deficient piants.

  20. Resistance to compression of weakened roots subjected to different root reconstruction protocols

    Directory of Open Access Journals (Sweden)

    Lucas Villaça Zogheib

    2011-12-01

    Full Text Available OBJECTIVE: This study evaluated, in vitro, the fracture resistance of human non-vital teeth restored with different reconstruction protocols. MATERIAL AND METHODS: Forty human anterior roots of similar shape and dimensions were assigned to four groups (n=10, according to the root reconstruction protocol: Group I (control: non-weakened roots with glass fiber post; Group II: roots with composite resin by incremental technique and glass fiber post; Group III: roots with accessory glass fiber posts and glass fiber post; and Group IV: roots with anatomic glass fiber post technique. Following post cementation and core reconstruction, the roots were embedded in chemically activated acrylic resin and submitted to fracture resistance testing, with a compressive load at an angle of 45º in relation to the long axis of the root at a speed of 0.5 mm/min until fracture. All data were statistically analyzed with bilateral Dunnett's test (α=0.05. RESULTS: Group I presented higher mean values of fracture resistance when compared with the three experimental groups, which, in turn, presented similar resistance to fracture among each other. None of the techniques of root reconstruction with intraradicular posts improved root strength, and the incremental technique was suggested as being the most recommendable, since the type of fracture that occurred allowed the remaining dental structure to be repaired. CONCLUSION: The results of this in vitro study suggest that the healthy remaining radicular dentin is more important to increase fracture resistance than the root reconstruction protocol.

  1. RootGraph: a graphic optimization tool for automated image analysis of plant roots.

    Science.gov (United States)

    Cai, Jinhai; Zeng, Zhanghui; Connor, Jason N; Huang, Chun Yuan; Melino, Vanessa; Kumar, Pankaj; Miklavcic, Stanley J

    2015-11-01

    This paper outlines a numerical scheme for accurate, detailed, and high-throughput image analysis of plant roots. In contrast to existing root image analysis tools that focus on root system-average traits, a novel, fully automated and robust approach for the detailed characterization of root traits, based on a graph optimization process is presented. The scheme, firstly, distinguishes primary roots from lateral roots and, secondly, quantifies a broad spectrum of root traits for each identified primary and lateral root. Thirdly, it associates lateral roots and their properties with the specific primary root from which the laterals emerge. The performance of this approach was evaluated through comparisons with other automated and semi-automated software solutions as well as against results based on manual measurements. The comparisons and subsequent application of the algorithm to an array of experimental data demonstrate that this method outperforms existing methods in terms of accuracy, robustness, and the ability to process root images under high-throughput conditions.

  2. Root phenology at Harvard Forest and beyond

    Science.gov (United States)

    Abramoff, R. Z.; Finzi, A.

    2013-12-01

    Roots are hidden from view and heterogeneously distributed making them difficult to study in situ. As a result, the causes and timing of root production are not well understood. Researchers have long assumed that above and belowground phenology is synchronous; for example, most parameterizations of belowground carbon allocation in terrestrial biosphere models are based on allometry and represent a fixed fraction of net C uptake. However, using results from metaanalysis as well as empirical data from oak and hemlock stands at Harvard Forest, we show that synchronous root and shoot growth is the exception rather than the rule. We collected root and shoot phenology measurements from studies across four biomes (boreal, temperate, Mediterranean, and subtropical). General patterns of root phenology varied widely with 1-5 production peaks in a growing season. Surprisingly, in 9 out of the 15 studies, the first root production peak was not the largest peak. In the majority of cases maximum shoot production occurred before root production (Offset>0 in 32 out of 47 plant sample means). The number of days offset between maximum root and shoot growth was negatively correlated with median annual temperature and therefore differs significantly across biomes (ANOVA, F3,43=9.47, pGrowth form (woody or herbaceous) also influenced the relative timing of root and shoot growth. Woody plants had a larger range of days between root and shoot growth peaks as well as a greater number of growth peaks. To explore the range of phenological relationships within woody plants in the temperate biome, we focused on above and belowground phenology in two common northeastern tree species, Quercus rubra and Tsuga canadensis. Greenness index, rate of stem growth, root production and nonstructural carbohydrate content were measured beginning in April 2012 through August 2013 at the Harvard Forest in Petersham, MA, USA. Greenness and stem growth were highest in late May and early June with one clear

  3. Root distribution of rootstocks for 'Tahiti' lime

    Directory of Open Access Journals (Sweden)

    Neves Carmen Silvia Vieira Janeiro

    2004-01-01

    Full Text Available Field studies on citrus roots are important for genetic selection of cultivars and for management practices such as localized irrigation and fertilization. To characterize root systems of six rootstocks, taking into consideration chemical and physical characteristics of a clayey Typic Hapludox of the Northern State of Paraná, this study was performed having as scion the 'IAC-5 Tahiti' lime [Citrus latifolia (Yu. Tanaka]. The rootstocks 'Rangpur' lime (C. limonia Osbeck, 'Africa Rough' lemon (C. jambhiri Lush., 'Sunki' mandarin [C. sunki (Hayata hort. ex Tan.], Poncirus trifoliata (L. Raf., 'C13' citrange [C. sinensis (L. Osb. x P. trifoliata (L. Raf] and 'Catânia 2' Volkamer lemon (C. volkameriana Ten. & Pasq. were used applying the trench profile method and the SIARCS® 3.0 software to determine root distribution. 'C-13' citrange had the largest root system. 'Volkamer' lemon and 'Africa Rough' lemon presented the smallest amount of roots. The effective depth for 80 % of roots was 31-53 cm in rows and 67-68 cm in inter-rows. The effective distance of 80 % of roots measured from the tree trunk exceeded the tree canopy for P. trifoliata, 'Sunki' mandarin, and 'Volkamer' and 'Africa Rough' lemons.

  4. A thermodynamic formulation of root water uptake

    Science.gov (United States)

    Hildebrandt, Anke; Kleidon, Axel; Bechmann, Marcel

    2016-08-01

    By extracting bound water from the soil and lifting it to the canopy, root systems of vegetation perform work. Here we describe how root water uptake can be evaluated thermodynamically and demonstrate that this evaluation provides additional insights into the factors that impede root water uptake. We derive an expression that relates the energy export at the base of the root system to a sum of terms that reflect all fluxes and storage changes along the flow path in thermodynamic terms. We illustrate this thermodynamic formulation using an idealized setup of scenarios with a simple model. In these scenarios, we demonstrate why heterogeneity in soil water distribution and rooting properties affect the impediment of water flow even though the mean soil water content and rooting properties are the same across the scenarios. The effects of heterogeneity can clearly be identified in the thermodynamics of the system in terms of differences in dissipative losses and hydraulic energy, resulting in an earlier start of water limitation in the drying cycle. We conclude that this thermodynamic evaluation of root water uptake conveniently provides insights into the impediments of different processes along the entire flow path, which goes beyond resistances and also accounts for the role of heterogeneity in soil water distribution.

  5. Spiralizations and tropisms in Arabidopsis roots.

    Science.gov (United States)

    Migliaccio, F; Piconese, S

    2001-12-01

    When Arabidopsis seedlings are grown on a hard-agar plate, their primary roots show characteristic spiralling movements, apparent as waves, coils and torsions, together with a slanting toward the right-hand side. All these movements are believed to be the result of three different processes acting on the roots: circumnutation, positive gravitropism and negative thigmotropism. The basic movement of the roots is described as that of a growing right-handed helix, which, because of the root tip hitting the agar plate, is continuously switched from the right-hand to the left-hand of the growth direction, and vice versa. This movement also produces a slanting root-growth direction toward the right-hand because of the incomplete waves made by the right-handed root to the left-hand. By contrast, the torsions seen in the coils and waves are interpreted as artefacts that form as an adaptation of the three-dimensional root helix to the flat two-dimensional agar surface.

  6. Tractography of lumbar nerve roots: initial results

    Energy Technology Data Exchange (ETDEWEB)

    Balbi, Vincent; Budzik, Jean-Francois; Thuc, Vianney le; Cotten, Anne [Hopital Roger Salengro, Service de Radiologie et d' Imagerie musculo-squelettique, Lille Cedex (France); Duhamel, Alain [Universite de Lille 2, UDSL, Lille (France); Bera-Louville, Anne [Service de Rhumatologie, Hopital Roger Salengro, Lille (France)

    2011-06-15

    The aims of this preliminary study were to demonstrate the feasibility of in vivo diffusion tensor imaging (DTI) and fibre tracking (FT) of the lumbar nerve roots, and to assess potential differences in the DTI parameters of the lumbar nerves between healthy volunteers and patients suffering from disc herniation. Nineteen patients with unilateral sciatica related to posterolateral or foraminal disc herniation and 19 healthy volunteers were enrolled in this study. DTI with tractography of the L5 or S1 nerves was performed. Mean fractional anisotropy (FA) and mean diffusivity (MD) values were calculated from tractography images. FA and MD values could be obtained from DTI-FT images in all controls and patients. The mean FA value of the compressed lumbar nerve roots was significantly lower than the FA of the contralateral nerve roots (p=0.0001) and of the nerve roots of volunteers (p=0.0001). MD was significantly higher in compressed nerve roots than in the contralateral nerve root (p=0.0002) and in the nerve roots of volunteers (p=0.04). DTI with tractography of the lumbar nerves is possible. Significant changes in diffusion parameters were found in the compressed lumbar nerves. (orig.)

  7. Culture in vitro and Plant Regeneration from Roots of Citrus paradisi Macf.Seedlings%葡萄柚(Citrus paradisi Macf.)实生苗根段的离体培养及植株再生研究

    Institute of Scientific and Technical Information of China (English)

    陶燕蓝; 蓝增全; 吴田

    2014-01-01

    Objective]The objective of the study was to establish regeneration system of C.para-disi in vitro and to provide useful references for the application of genetic transformation tech-nique.[Method]The roots of aseptic seedlings germinated from the seeds of 10 grapefruit varie-ties were cultured in vitro to obtain regeneration plants in the medium with different hormones and concentrations.[Results]The callus were observed in the medium MS+0.5 mg/L 6-BA+0.5 mg/L NAA and Perlist had the highest callus induction frequency (87.95%).The differentia-tion of adventitious buds was observed in the medium MS+2.0 mg/L 6-BA+0.5 mg/L NAA and Star Ruby had the largest differentiation rate of adventitious buds (37.84%).The regeneration buds were multiplied in the medium MS+2.0 mg/L 6-BA+0.2 mg/L NAA.The adventitious roots were induced in the medium 1/2 MS +1.0 mg/L IBA and the regeneration plants finally were obtained.The survival rates of regenerative plant ranged from 75.47% to 88.40%.[Con-clusion]The regeneration systems of 6 grapefruit varieties were established based on the study.%【目的】建立葡萄柚(Citrus paradisi Macf.)离体再生体系,为后续遗传转化体系的建立奠定基础。【方法】以10个葡萄柚品种种子萌发的无菌苗根段为材料,在附加不同植物激素种类及浓度的培养基上进行离体培养,并获得再生植株。【结果】在 MS+0.5 mg/L 6-BA+0.5 mg/L NAA 培养基上培养可以诱导出愈伤组织,其中“帕利斯”的诱导率最高,达87.95%;在培养基 MS+2.0 mg/L 6-BA+0.5 mg/L NAA 可分化出丛生芽,其中“星路比”分化率最高为37.84%;分化出的丛生芽在 MS+2.0 mg/L 6-BA+0.2 mg/L NAA 培养基上可以进行增殖培养;在1/2 MS+1.0 mg/L IBA 上可诱导出不定根,形成完整再生植株。炼苗移栽成活率均可达75.47%~88.40%。【结论】通过对10个葡萄柚品种根段

  8. Effects of acid deposition on tree roots

    Energy Technology Data Exchange (ETDEWEB)

    Persson, H. [Swedish Univ. of Agricultural Sciences (Sweden). Dept. of Ecology and Environmental Research

    1995-12-31

    Large forest regions in SW Sweden have been exposed to high levels of acid deposition for many decades, causing soil acidification in forest soils. Historically, SO{sub 2} has been the major acidification agent, but lately nitrogen compounds increasingly have become important. The amount and chemical form of nitrogen strongly affects the pH in the rhizosphere and rhizoplane. Many forest stands show a positive growth response to increased nitrogen input, even in heavily N-loaded areas. Nitrogen fertilization experiments suggest that part of the increased forest production is caused by a translocation of biomass production from below-ground to above-ground parts. At the same time fine-root growth dynamics are strongly affected by the high N supply. Deficiencies of various nutrients (Mg,Ca,K,Mn and Zn) obtained from needle analyses have been reported from different Picea abies stands. In areas with more extensive acidification and nutrient leaching, a decline in tree vitality has been observed. Although deficiency symptoms in forest trees may be reflected in nitrogen/cation ratios in fine roots, few attempts have been made to explain forest damage symptoms from fine-root chemistry. Root damage is often described as a decline in the amount of living fine roots, an increase in the amount of dead versus live fine roots (a lower live/dead ratio) and an increasing amount of dead medium and coarse roots. The primary objectives of the present presentation were to analyse available data on the effects of high nitrogen and sulphur deposition on mineral nutrient balance in tree fine roots and to evaluate the risk of Al interference with cation uptake by roots

  9. 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

  10. 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

  11. A "square-root rule" for reinsurance

    Directory of Open Access Journals (Sweden)

    Michael R. Powers

    2006-12-01

    Full Text Available In previous work, the authors derived a mathematical expression for the optimal (or "saturation" number of reinsurers for a given number of primary insurers (see Powers and Shubik, 2001. In the current article, we show analytically that, for large numbers of primary insurers, this mathematical expression provides a "square-root rule"; i.e., the optimal number of reinsurers in a market is given asymptotically by the square root of the total number of primary insurers. We note further that an analogous "fourth-root rule" applies to markets for retrocession (the reinsurance of reinsurance.

  12. Clinical technique for invasive cervical root resorption

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Machado Silveira

    2011-01-01

    Full Text Available This clinical case report describes the diagnosis and treatment of an external invasive cervical resorption. A 17-year-old female patient had a confirmed diagnosis of invasive cervical resorption class 4 by cone beam computerized tomography. Although, there was no communication with the root canal, the invasive resorption process was extending into the cervical and middle third of the root. The treatment of the cervical resorption of the lateral incisor interrupted the resorptive process and restored the damaged root surface and the dental functions without any esthetic sequelae. Both the radiographic examination and computed tomography are imperative to reveal the extent of the defect in the differential diagnosis.

  13. ANTIARTHRITIC ACTIVITY OF DESMODIUM GANGETICUM ROOT

    Directory of Open Access Journals (Sweden)

    Vedpal

    2013-09-01

    Full Text Available The present study is aimed to evaluate the in-vitro anti-arthritic activity of aqueous extract of Desmodium gangeticum root using inhibition of protein denaturation model and human red blood cell Membrane stabilization model. Diclofenac sodium was used as a standard drug. Results revealed that the aqueous extract of Desmodium gangeticum root at different concentrations possessed significant anti-arthritic activity as compared to standard drug used as Diclofenac sodium. The results obtained in the present investigation Indicate that aqueous extract of Desmodium gangeticum root showed anti-arthritic activity.

  14. BOREAS TE-2 Root Respiration Data

    Science.gov (United States)

    Ryan, Michael G.; Lavigne, Michael; Hall, Forrest G. (Editor); Papagno, Andrea (Editor)

    2000-01-01

    The BOREAS TE-2 team collected several data sets in support of its efforts to characterize and interpret information on the respiration of the foliage, roots, and wood of boreal vegetation. This data set includes means of tree root respiration measurements on roots having diameters ranging from 0 to 2 mm conducted in the NSA during the growing season of 1994. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  15. THttpServer class in ROOT

    Science.gov (United States)

    Adamczewski-Musch, Joern; Linev, Sergey

    2015-12-01

    The new THttpServer class in ROOT implements HTTP server for arbitrary ROOT applications. It is based on Civetweb embeddable HTTP server and provides direct access to all objects registered for the server. Objects data could be provided in different formats: binary, XML, GIF/PNG, and JSON. A generic user interface for THttpServer has been implemented with HTML/JavaScript based on JavaScript ROOT development. With any modern web browser one could list, display, and monitor objects available on the server. THttpServer is used in Go4 framework to provide HTTP interface to the online analysis.

  16. 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

  17. Phosphate Availability Alters Lateral Root Anatomy and Root Architecture of Fraxinus mandshurica Rupr. Seedlings

    Institute of Scientific and Technical Information of China (English)

    Chu WU; Xing WEI; Hai-Long SUN; Zheng-Quan WANG

    2005-01-01

    Plants have evolved some mechanisms to maximize the efficiency of phosphorus acquisition.Changes in root architecture are one such mechanism. When Fraxinus mandshurica Rupr. seedlings were grown under conditions of low phosphorus availability, the length of cells in the meristem zone of the lateral roots was longer, but the length of cells in the elongation and mature zones of the lateral roots was shorter,compared with seedlings grown under conditions of high phosphorus availability. The elongation rates of primary roots increased as phosphorus availability increased, but the elongation rates of the branched zones of the primary roots decreased. The number of lateral root primordia and the length of the lateral roots decreased as phosphorus availability increased. The topological index (altitude slope) decreased as phosphorus availability increased, suggesting that root architecture tended to be herringbone-like when seedlings were grown under conditions of low phosphate availability. Herringbone-like root systems exploit nutrients more efficiently, but they have higher construction costs than root systems with a branching pattern.

  18. 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.

  19. Plant roots use a patterning mechanism to position lateral root branches toward available water.

    Science.gov (United States)

    Bao, Yun; Aggarwal, Pooja; Robbins, Neil E; Sturrock, Craig J; Thompson, Mark C; Tan, Han Qi; Tham, Cliff; Duan, Lina; Rodriguez, Pedro L; Vernoux, Teva; Mooney, Sacha J; Bennett, Malcolm J; Dinneny, José R

    2014-06-24

    The architecture of the branched root system of plants is a major determinant of vigor. Water availability is known to impact root physiology and growth; however, the spatial scale at which this stimulus influences root architecture is poorly understood. Here we reveal that differences in the availability of water across the circumferential axis of the root create spatial cues that determine the position of lateral root branches. We show that roots of several plant species can distinguish between a wet surface and air environments and that this also impacts the patterning of root hairs, anthocyanins, and aerenchyma in a phenomenon we describe as hydropatterning. This environmental response is distinct from a touch response and requires available water to induce lateral roots along a contacted surface. X-ray microscale computed tomography and 3D reconstruction of soil-grown root systems demonstrate that such responses also occur under physiologically relevant conditions. Using early-stage lateral root markers, we show that hydropatterning acts before the initiation stage and likely determines the circumferential position at which lateral root founder cells are specified. Hydropatterning is independent of endogenous abscisic acid signaling, distinguishing it from a classic water-stress response. Higher water availability induces the biosynthesis and transport of the lateral root-inductive signal auxin through local regulation of tryptophan aminotransferase of Arabidopsis 1 and PIN-formed 3, both of which are necessary for normal hydropatterning. Our work suggests that water availability is sensed and interpreted at the suborgan level and locally patterns a wide variety of developmental processes in the root.

  20. Rooting depths of plants relative to biological and environmental factors

    Energy Technology Data Exchange (ETDEWEB)

    Foxx, T S; Tierney, G D; Williams, J M

    1984-11-01

    In 1981 to 1982 an extensive bibliographic study was completed to document rooting depths of native plants in the United States. The data base presently contains 1034 citations with approximately 12,000 data elements. In this paper the data were analyzed for rooting depths as related to life form, soil type, geographical region, root type, family, root depth to shoot height ratios, and root depth to root lateral ratios. Average rooting depth and rooting frequencies were determined and related to present low-level waste site maintenance.

  1. Effect of two contemporary root canal sealers on root canal dentin microhardness

    Science.gov (United States)

    2017-01-01

    Background Successful root canal treatment depends on proper cleaning, disinfecting and shaping of the root canal space. Pulpless teeth have lower dentin microhardness value compared to that of vital teeth. A material which can cause change in dentin composition may affect the microhardness. Thus the aim of this study was to evaluate and compare the effect of two root canal sealers on dentin microhardness. Material and Methods Forty two single rooted teeth were selected and divided into 3 equal groups; Apexit, iRootSP and control groups (n=14) Each group was then divided into 2 subgroups according to the post evaluation period; 1 week and 2 months (n=7). Root canal procedure was done in the experimental groups and obturation was made using either; Apexit, iRootSP or left unprepared and unobturated in the control group. Roots were sectioned transversely into cervical, middle and apical segments. The three sections of each root were mounted in a plastic chuck with acrylic resin. The coronal dentin surfaces of the root segments werepolished. Microhardness of each section was measured at 500 µm and 1000 µm from the canal lumen. Results Four way-ANOVA revealed that different tested sealer materials, canal third, measuring distance from the pulp and time as independent variables had statistically non significant effect on mean microhardness values (VHN) at p≤0.001. Among iRootSP groups there was a statistically significant difference between iRoot SP at coronal root portion (87.79±17.83) and iRoot SP at apical root portion (76.26±9.33) groups where (p=0.01). IRoot SP at coronal canal third had higher statistically significant mean microhardness value (87.79±17.83) compared to Apexit at coronal third (73.61±13.47) where (p=0.01). Conclusions Root canal sealers do not affect dentin microhardness. Key words:Root canal, dentin, sealers, microhardness, bioceramic. PMID:28149466

  2. DMA thermal analysis of yacon tuberous roots

    Science.gov (United States)

    Blahovec, J.; Lahodová, M.; Kindl, M.; Fernández, E. C.

    2013-12-01

    Specimens prepared from yacon roots in first two weeks after harvest were tested by dynamic mechanical analysis thermal analysis at temperatures between 30 and 90°C. No differences between different parts of roots were proved. There were indicated some differences in the test parameters that were caused by short time storage of the roots. One source of the differences was loss of water during the roots storage. The measured modulus increased during short time storage. Detailed study of changes of the modulus during the specimen dynamic mechanical analysis test provided information about different development of the storage and loss moduli during the specimen heating. The observed results can be caused by changes in cellular membranes observed earlier during vegetable heating, and by composition changes due to less stable components of yacon like inulin.

  3. Tree root systems and nutrient mobilization

    DEFF Research Database (Denmark)

    Boyle, Jim; Rob, Harrison; Raulund-Rasmussen, Karsten

    Roots mobilize nutrients via deep penetration and rhizosphere processes inducing weathering of primary minerals. These contribute to C transfer to soils and to tree nutrition. Assessments of these characteristics and processes of root systems are important for understanding long-term supplies...... some of the world’s most productive intensively managed forests, including Brazil and the Southeast and Pacifi c Northwest regions of the United States, have shown that root systems are often several meters in depth, and often extend deeper than soil is sampled. Large amounts of carbon are also...... sometimes stored at depth. Other recent studies on potential release of nutrients due to chemical weathering indicate the importance of root access to deep soil layers. Release profi les clearly indicate depletion in the top layers and a much higher potential in B and C horizons. Review of evaluations...

  4. BGP reflection functors in root categories

    Institute of Scientific and Technical Information of China (English)

    XIAO Jie; ZHANG Guanglian; ZHU Bin

    2005-01-01

    We define the BGP-reflection functors in the derived categories and the root categories. By Ringel's Hall algebra approach, the BGP-reflection functor is applicable to obtain the classical Weyl group action on the Lie algebra.

  5. Tooth mobility changes subsequent to root fractures

    DEFF Research Database (Denmark)

    Andreasen, Jens Ove; Christensen, Søren Steno Ahrensburg; Tsilingaridis, Georgios

    2012-01-01

    of pulp necrosis in the coronal fragment. Furthermore, the effect of age, location of the fracture on the root, and observation period on mobility values was analyzed. Mobility values were measured for 44 of 95 previous reported root-fractured permanent incisors. Mobility changes were measured......The purpose of this study was to analyze tooth mobility changes in root-fractured permanent teeth and relate this to type of interfragment healing (hard tissue healing (HT), interfragment healing with periodontal ligament (PDL) and nonhealing with interposition of granulation tissue (GT) because...... after 3 months and 1 year, and a normalization of mobility value was usually found after 5 and 10 years. In 17 cases of PDL healing, generally a higher mobility was found in comparison with root fractures healing with hard tissue, and a consistent decrease in mobility value was found in the course...

  6. Naine objektistab meest / Fideelia-Signe Roots

    Index Scriptorium Estoniae

    Roots, Fideelia-Signe, 1976-

    2009-01-01

    Fideelia-Signe Roots Eesti Kunstiakadeemias 2009. a. kevadsemestril enda poolt läbi viidud valikainekursusest "Kunstiteose anatoomiast mehe anatoomiani", mis lõppes näitusega "Tõuseb / ei tõuse" Eesti Tervishoiumuuseumis, avatud 31. maini

  7. Elements with Square Roots in Finite Groups

    Institute of Scientific and Technical Information of China (English)

    M.S. Lucido; M.R. Pournaki

    2005-01-01

    In this paper, we study the probability that a randomly chosen element in a finite group has a square root, in particular the simple groups of Lie type of rank 1, the sporadic finite simple groups and the alternating groups.

  8. Dechlorodauricumine from cultured roots of Menispermum dauricum.

    Science.gov (United States)

    Sugimoto, Yukihiro; Matsui, Miharu; Takikawa, Hirosato; Sasaki, Mitsuru; Kato, Masako

    2005-11-01

    Dechlorodauricumine, a possible organic substrate for biochlorination, was isolated from cultured roots of Menispermum dauricum, a rich source of chlorinated alkaloids. Its structure was established by spectroscopic and chemical methods.

  9. 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).

  10. 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.

  11. Sparse DOA estimation with polynomial rooting

    OpenAIRE

    Xenaki, Angeliki; Gerstoft, Peter; Fernandez Grande, Efren

    2015-01-01

    Direction-of-arrival (DOA) estimation involves the localization of a few sources from a limited number of observations on an array of sensors. Thus, DOA estimation can be formulated as a sparse signal reconstruction problem and solved efficiently with compressive sensing (CS) to achieve highresolution imaging. Utilizing the dual optimal variables of the CS optimization problem, it is shown with Monte Carlo simulations that the DOAs are accurately reconstructed through polynomial rooting (Root...

  12. Rational Convolution Roots of Isobaric Polynomials

    OpenAIRE

    Conci, Aura; Li, Huilan; MacHenry, Trueman

    2014-01-01

    In this paper, we exhibit two matrix representations of the rational roots of generalized Fibonacci polynomials (GFPs) under convolution product, in terms of determinants and permanents, respectively. The underlying root formulas for GFPs and for weighted isobaric polynomials (WIPs), which appeared in an earlier paper by MacHenry and Tudose, make use of two types of operators. These operators are derived from the generating functions for Stirling numbers of the first kind and second kind. Hen...

  13. Operating protocols of external root cervical resorption

    OpenAIRE

    Luca Venuti

    2015-01-01

    Aim: Theme of this report is the external cervical root resorption and the sequence of clinical procedures to be implemented during the phases of treatment. The external cervical root resorption (ICR) presents particular pathological conditions such as to classify between resorption of inflammatory origin.1–3 It is generally presented as a complex clinical situation both in the diagnosis in a predictable prognosis.3–6 It's often associated with loss of calcified tissue: dentin, cementum, a...

  14. 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.

  15. Two root canals in maxillary central incisor

    Directory of Open Access Journals (Sweden)

    Fábio de Almeida Gomes

    2011-07-01

    Full Text Available Introduction and objective: The success of endodontic treatment requires the knowledge of tooth morphology and its variations. Case report: This clinical article reports an unusual root canal configuration that was detected in a maxillary central incisor with two root canals, demonstrated by radiographic and computerized tomography exams. Conclusion: Knowledge of endodontic anatomy as well as the obtainment of both preoperative radiographs and tomography is important to detect abnormal tooth morphology.

  16. Relationships between root respiration rate and root morphology, chemistry and anatomy in Larix gmelinii and Fraxinus mandshurica.

    Science.gov (United States)

    Jia, Shuxia; McLaughlin, Neil B; Gu, Jiacun; Li, Xingpeng; Wang, Zhengquan

    2013-06-01

    Tree roots are highly heterogeneous in form and function. Previous studies revealed that fine root respiration was related to root morphology, tissue nitrogen (N) concentration and temperature, and varied with both soil depth and season. The underlying mechanisms governing the relationship between root respiration and root morphology, chemistry and anatomy along the root branch order have not been addressed. Here, we examined these relationships of the first- to fifth-order roots for near surface roots (0-10 cm) of 22-year-old larch (Larix gmelinii L.) and ash (Fraxinus mandshurica L.) plantations. Root respiration rate at 18 °C was measured by gas phase O2 electrodes across the first five branching order roots (the distal roots numbered as first order) at three times of the year. Root parameters of root diameter, specific root length (SRL), tissue N concentration, total non-structural carbohydrates (starch and soluble sugar) concentration (TNC), cortical thickness and stele diameter were also measured concurrently. With increasing root order, root diameter, TNC and the ratio of root TNC to tissue N concentration increased, while the SRL, tissue N concentration and cortical proportion decreased. Root respiration rate also monotonically decreased with increasing root order in both species. Cortical tissue (including exodermis, cortical parenchyma and endodermis) was present in the first three order roots, and cross sections of the cortex for the first-order root accounted for 68% (larch) and 86% (ash) of the total cross section of the root. Root respiration was closely related to root traits such as diameter, SRL, tissue N concentration, root TNC : tissue N ratio and stele-to-root diameter proportion among the first five orders, which explained up to 81-94% of variation in the rate of root respiration for larch and up to 83-93% for ash. These results suggest that the systematic variations of root respiration rate within tree fine root system are possibly due to the

  17. Acid protease production in fungal root endophytes.

    Science.gov (United States)

    Mayerhofer, Michael S; Fraser, Erica; Kernaghan, Gavin

    2015-01-01

    Fungal endophytes are ubiquitous in healthy root tissue, but little is known about their ecosystem functions, including their ability to utilize organic nutrient sources such as proteins. Root-associated fungi may secrete proteases to access the carbon and mineral nutrients within proteins in the soil or in the cells of their plant host. We compared the protein utilization patterns of multiple isolates of the root endophytes Phialocephala fortinii s.l., Meliniomyces variabilis and Umbelopsis isabellina with those of two ectomycorrhizal (ECM) fungi, Hebeloma incarnatulum and Laccaria bicolor, and the wood-decay fungus Irpex lacteus at pH values of 2-9 on liquid BSA media. We also assessed protease activity using a fluorescently labeled casein assay and gelatin zymography and characterized proteases using specific protease inhibitors. I. lacteus and U. isabellina utilized protein efficiently, while the ECM fungi exhibited poor protein utilization. ECM fungi secreted metallo-proteases and had pH optima above 4, while other fungi produced aspartic proteases with lower pH optima. The ascomycetous root endophytes M. variabilis and P. fortinii exhibited intermediate levels of protein utilization and M. variabilis exhibited a very low pH optimum. Comparing proteolytic profiles between fungal root endophytes and fungi with well defined ecological roles provides insight into the ecology of these cryptic root associates.

  18. Extracellular DNA: the tip of root defenses?

    Science.gov (United States)

    Hawes, Martha C; Curlango-Rivera, Gilberto; Wen, Fushi; White, Gerard J; Vanetten, Hans D; Xiong, Zhongguo

    2011-06-01

    This review discusses how extracellular DNA (exDNA) might function in plant defense, and at what level(s) of innate immunity this process might operate. A new role for extracellular factors in mammalian defense has been described in a series of studies. These studies reveal that cells including neutrophils, eosinophils, and mast cells produce 'extracellular traps' (ETs) consisting of histone-linked exDNA. When pathogens are attracted to such ETs, they are trapped and killed. When the exDNA component of ETs is degraded, trapping is impaired and resistance against invasion is reduced. Conversely, mutation of microbial genes encoding exDNases that degrade exDNA results in loss of virulence. This discovery that exDNases are virulence factors opens new avenues for disease control. In plants, exDNA is required for defense of the root tip. Innate immunity-related proteins are among a group of >100 proteins secreted from the root cap and root border cell populations. Direct tests revealed that exDNA also is rapidly synthesized and exported from the root tip. When this exDNA is degraded by the endonuclease DNase 1, root tip resistance to fungal infection is lost; when the polymeric structure is degraded more slowly, by the exonuclease BAL31, loss of resistance to fungal infection is delayed accordingly. The results suggest that root border cells may function in a manner analogous to that which occurs in mammalian cells.

  19. Tomato Root Response to Subsurface Drip Irrigation

    Institute of Scientific and Technical Information of China (English)

    ZHUGE Yu-Ping; ZHANG Xu-Dong; ZHANG Yu-Long; LI Jun; YANG Li-Juan; HUANG Yi; LIU Ming-Da

    2004-01-01

    Four depth treatments of subsurface drip irrigation pipes were designated as 1) at 20,2) 30 and 3) 40 cm depths all with a drip-proof flumes underneath,and 4) at 30 cm without a drip-proof flume to investigate the responses of a tomato root system to different technical parameters of subsurface drip irrigation in a glass greenhouse,to evaluate tomato growth as affected by subsurface drip irrigation,and to develop an integrated subsurface drip irrigation method for optimal tomato yield and water use in a glass greenhouse. Tomato seedlings were planted above the subsurface drip irrigation pipe. Most of the tomato roots in treatment 1 were found in the top 0-20 cm soil depth with weak root activity but with yield and water use efficiency (WUE) significantly less (P ---- 0.05) than treatment 2; root activity and tomato yield were significantly higher (P = 0.05) with treatment 3 compared to treatment 1; and with treatment 2 the tomato roots and shoots grew harmoniously with root activity,nutrient uptake,tomato yield and WUE significantly higher (P= 0.05) or as high as the other treatments. These findings suggested that subsurface drip irrigation with pipes at 30 cm depth with a drip-proof flume placed underneath was best for tomato production in greenhouses. In addition,the irrigation interval should be about 7-8 days and the irrigation rate should be set to 225 m3 ha-1 per event.

  20. Roots of Dehn twists about separating curves

    CERN Document Server

    Rajeevsarathy, Kashyap

    2011-01-01

    Let $C$ be a curve in a closed orientable surface $F$ of genus $g \\geq 2$ that separates $F$ into subsurfaces $\\widetilde {F_i}$ of genera $g_i$, for $i = 1,2$. We study the set of roots in $\\Mod(F)$ of the Dehn twist $t_C$ about $C$. All roots arise from pairs of $C_{n_i}$-actions on the $\\widetilde{F_i}$, where $n=\\lcm(n_1,n_2)$ is the degree of the root, that satisfy a certain compatibility condition. The $C_{n_i}$ actions are of a kind that we call nestled actions, and we classify them using tuples that we call data sets. The compatibility condition can be expressed by a simple formula, allowing a classification of all roots of $t_C$ by compatible pairs of data sets. We use these data set pairs to classify all roots for $g = 2$ and $g = 3$. We show that there is always a root of degree at least $2g^2+2g$, while $n \\leq 4g^2+2g$. We also give some additional applications.

  1. Gene expression regulation in roots under drought.

    Science.gov (United States)

    Janiak, Agnieszka; Kwaśniewski, Mirosław; Szarejko, Iwona

    2016-02-01

    Stress signalling and regulatory networks controlling expression of target genes are the basis of plant response to drought. Roots are the first organs exposed to water deficiency in the soil and are the place of drought sensing. Signalling cascades transfer chemical signals toward the shoot and initiate molecular responses that lead to the biochemical and morphological changes that allow plants to be protected against water loss and to tolerate stress conditions. Here, we present an overview of signalling network and gene expression regulation pathways that are actively induced in roots under drought stress. In particular, the role of several transcription factor (TF) families, including DREB, AP2/ERF, NAC, bZIP, MYC, CAMTA, Alfin-like and Q-type ZFP, in the regulation of root response to drought are highlighted. The information provided includes available data on mutual interactions between these TFs together with their regulation by plant hormones and other signalling molecules. The most significant downstream target genes and molecular processes that are controlled by the regulatory factors are given. These data are also coupled with information about the influence of the described regulatory networks on root traits and root development which may translate to enhanced drought tolerance. This is the first literature survey demonstrating the gene expression regulatory machinery that is induced by drought stress, presented from the perspective of roots.

  2. Defining the core Arabidopsis thaliana root microbiome

    Science.gov (United States)

    Gehring, Jase; Malfatti, Stephanie; Tremblay, Julien; Engelbrektson, Anna; Kunin, Victor; del Rio, Tijana Glavina; Edgar, Robert C.; Eickhorst, Thilo; Ley, Ruth E.; Hugenholtz, Philip; Tringe, Susannah Green; Dangl, Jeffery L.

    2014-01-01

    Land plants associate with a root microbiota distinct from the complex microbial community present in surrounding soil. The microbiota colonizing therhizosphere(immediately surroundingthe root) and the endophytic compartment (within the root) contribute to plant growth, productivity, carbon sequestration and phytoremediation1-3. Colonization of the root occurs despite a sophisticated plant immune system4,5, suggesting finely tuned discrimination of mutualists and commensals from pathogens. Genetic principles governing the derivation of host-specific endophyte communities from soil communities are poorly understood. Here we report the pyrosequencing of the bacterial 16S ribosomal RNA gene of more than 600 Arabidopsis thaliana plants to test the hypotheses that the root rhizosphere and endophytic compartment microbiota of plants grown under controlled conditions in natural soils are sufficiently dependent on the host to remain consistent across different soil types and developmental stages, and sufficiently dependent on host genotype to vary between inbred Arabidopsis accessions. We describe different bacterial communities in two geochemically distinct bulk soils and in rhizosphere and endophytic compartments prepared from roots grown in these soils. The communities in each compartment are strongly influenced by soil type. Endophytic compartments from both soils feature overlapping, low-complexity communities that are markedly enriched in Actinobacteria and specific families from other phyla, notably Proteobacteria. Some bacteria vary quantitatively between plants of different developmental stage and genotype. Our rigorous definition of an endophytic compartment microbiome should facilitate controlled dissection of plantmicrobe interactions derived from complex soil communities. PMID:22859206

  3. Short-term tissue response to potential root-end filling materials in infected root canals.

    Science.gov (United States)

    Chong, B S; Pitt Ford, T R; Kariyawasam, S P

    1997-07-01

    The short-term tissue responses to two potential root-end filling materials, a light-cured glass ionomer cement (Vitrebond) and a reinforced zinc oxide-eugenol cement (Kalzinol), were compared with that to amalgam using a previously devised experimental model. In 24 premolar teeth of beagle dogs (47 roots), a collection of endodontic pathogenic bacteria was first inoculated into the root canals to induce periradicular lesions. On each root, an apicoectomy was performed and root-end cavities prepared to receive fillings of each material. The teeth and surrounding jaw were removed after 2 weeks (23 roots) and 1 week (24 roots); they were then prepared for histological examination. The tissue response to amalgam fillings after 2 weeks and 1 week was marked by moderate or severe inflammation on all roots, and extended to 0.5 mm in 15 out of 16 roots. In contrast, after 2 weeks, the majority of roots filled with Kalzinol showed little or moderate inflammation, while the tissue response to Vitrebond was the best of the three materials, and was also the least extensive. After 1 week, the overall best tissue response was with Vitrebond, followed by Kalzinol. The differences between materials for both time periods with either none or few inflammatory cells when compared with that with either moderate or severe inflammation were not statistically significant (P inflammation or inflammation extending inflammation extending > 0.2 mm ( 0.5 mm) were statistically significant (P inflammation adjacent to the root-end filling, even though there were intersample variations, there was little overall difference in the temporal and qualitative healing response to Vitrebond and Kalzinol. Both Vitrebond and Kalzinol have potential as root-end filling materials, as the tissue response was considerably more favourable than that to amalgam even in the short-term.

  4. New insights to lateral rooting: Differential responses to heterogeneous nitrogen availability among maize root types.

    Science.gov (United States)

    Yu, Peng; White, Philip J; Li, Chunjian

    2015-01-01

    Historical domestication and the "Green revolution" have both contributed to the evolution of modern, high-performance crops. Together with increased irrigation and application of chemical fertilizers, these efforts have generated sufficient food for the growing global population. Root architecture, and in particular root branching, plays an important role in the acquisition of water and nutrients, plant performance, and crop yield. Better understanding of root growth and responses to the belowground environment could contribute to overcoming the challenges faced by agriculture today. Manipulating the abilities of crop root systems to explore and exploit the soil environment could enable plants to make the most of soil resources, increase stress tolerance and improve grain yields, while simultaneously reducing environmental degradation. In this article it is noted that the control of root branching, and the responses of root architecture to nitrate availability, differ between root types and between plant species. Since the control of root branching depends upon both plant species and root type, further work is urgently required to determine the appropriate genes to manipulate to improve resource acquisition by specific crops.

  5. Enhanced MRI in compressed lumbosacral nerve root; Alteration of vascular peameability in nerve root

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Tomofumi; Yoshizawa, Hidezo; Nakai, Sadaaki; Kobayashi, Shigeru; Hachiya, Hiromichi; Nakagawa, Masato; Nishimoto, Satoshi (Fujita Health Univ., Toyoake, Aichi (Japan). School of Medicine)

    1993-04-01

    The study was undertaken to assess how enhanced MRI reflects pathophysiology of the nerve root. In fundamental study, the seventh left lumbar nerve root was compressed by a clip for one hour in 10 mongrel dogs. Thirty min after removal of mechanical compression, gadolinium and Evans blue albumin (EBA) were iv injected. Then, the dogs were killed 10 min later. A mass of lumbosacral nerve root was removed for MR imaging. In addition, nerve root slices were prepared to examine changes in vascular permeability of EBA under microscopy. The compression area of nerve root was seen as hyperintensity on enhanced MRI, corresponding to extravascular leakage of EBA that resulted from the damaged blood-nerve barrier, i.e., edema within the root on microscope. In a clinical setting, 27 patients with lumbar disc herniation underwent MRI for the observation of the nerve root. In 8 of these 27 patients, the nerve root was seen as hyperintensity. This suggests that approximately one third of such patients may have edema within the nerve root. (N.K.).

  6. Capturing Arabidopsis root architecture dynamics with ROOT-FIT reveals diversity in responses to salinity.

    Science.gov (United States)

    Julkowska, Magdalena M; Hoefsloot, Huub C J; Mol, Selena; Feron, Richard; de Boer, Gert-Jan; Haring, Michel A; Testerink, Christa

    2014-11-01

    The plant root is the first organ to encounter salinity stress, but the effect of salinity on root system architecture (RSA) remains elusive. Both the reduction in main root (MR) elongation and the redistribution of the root mass between MRs and lateral roots (LRs) are likely to play crucial roles in water extraction efficiency and ion exclusion. To establish which RSA parameters are responsive to salt stress, we performed a detailed time course experiment in which Arabidopsis (Arabidopsis thaliana) seedlings were grown on agar plates under different salt stress conditions. We captured RSA dynamics with quadratic growth functions (root-fit) and summarized the salt-induced differences in RSA dynamics in three growth parameters: MR elongation, average LR elongation, and increase in number of LRs. In the ecotype Columbia-0 accession of Arabidopsis, salt stress affected MR elongation more severely than LR elongation and an increase in LRs, leading to a significantly altered RSA. By quantifying RSA dynamics of 31 different Arabidopsis accessions in control and mild salt stress conditions, different strategies for regulation of MR and LR meristems and root branching were revealed. Different RSA strategies partially correlated with natural variation in abscisic acid sensitivity and different Na(+)/K(+) ratios in shoots of seedlings grown under mild salt stress. Applying root-fit to describe the dynamics of RSA allowed us to uncover the natural diversity in root morphology and cluster it into four response types that otherwise would have been overlooked.

  7. Root caries, root surface restorations and lifestyle factors in adult Danes

    DEFF Research Database (Denmark)

    Christensen, Lisa Bøge; Jensen, Allan Bardow; Ekstrand, Kim

    2015-01-01

    AIM: To investigate selected lifestyle factors in relation to active caries and restored root surface lesions in adults. MATERIALS AND METHODS: Based on clinical examinations and questionnaires, data on root caries, socioeconomic status, body mass index, dietary habits, alcohol consumption, tobacco...... dentures were significantly associated with presence of active root caries (p tobacco use and alcohol...... consumption, as well as wearing dentures, were significantly associated with the occurrence of untreated caries and restored root surface lesions, especially in persons over 45. Thus, such lifestyle factors should be taken into consideration, identifying persons with a need of preventive dental services...

  8. Root cortical senescence decreases root respiration, nutrient content, and radial water and nutrient transport in barley.

    Science.gov (United States)

    Schneider, Hannah M; Wojciechowski, Tobias; Postma, Johannes A; Brown, Kathleen M; Lücke, Andreas; Zeisler, Viktoria; Schreiber, Lukas; Lynch, Jonathan P

    2017-02-06

    The functional implications of root cortical senescence (RCS) are poorly understood. We tested the hypotheses that RCS in barley: (1) reduces the respiration and nutrient content of root tissue; (2) decreases radial water and nutrient transport; (3) is accompanied by increased suberization to protect the stele. Genetic variation for RCS exists between modern germplasm and landraces. Nitrogen and phosphorus deficiency increased the rate of RCS. Maximal RCS, defined as the disappearance of the entire root cortex, reduced root nitrogen content by 66%, phosphorus content by 63%, and respiration by 87% compared to root segments with no RCS. Roots with maximal RCS had 90%, 92%, and 84% less radial water, nitrate, and phosphorus transport, respectively compared to segments with no RCS. The onset of RCS coincided with 30% greater aliphatic suberin in the endodermis. These results support the hypothesis that RCS reduces root carbon and nutrient costs and may therefore have adaptive significance for soil resource acquisition. By reducing root respiration and nutrient content, RCS could permit greater root growth, soil resource acquisition, and resource allocation to other plant processes. RCS merits investigation as a trait for improving the performance of barley, wheat, triticale, and rye under edaphic stress.

  9. Plant root tortuosity: an indicator of root path formation in soil with different composition and density

    Science.gov (United States)

    Popova, Liyana; van Dusschoten, Dagmar; Nagel, Kerstin A.; Fiorani, Fabio; Mazzolai, Barbara

    2016-01-01

    Background and Aims Root soil penetration and path optimization are fundamental for root development in soil. We describe the influence of soil strength on root elongation rate and diameter, response to gravity, and root-structure tortuosity, estimated by average curvature of primary maize roots. Methods Soils with different densities (1·5, 1·6, 1·7 g cm−3), particle sizes (sandy loam; coarse sand mixed with sandy loam) and layering (monolayer, bilayer) were used. In total, five treatments were performed: Mix_low with mixed sand low density (three pots, 12 plants), Mix_medium - mixed sand medium density (three pots, 12 plants), Mix_high - mixed sand high density (three pots, ten plants), Loam_low sandy loam soil low density (four pots, 16 plants), and Bilayer with top layer of sandy loam and bottom layer mixed sand both of low density (four pots, 16 plants). We used non-invasive three-dimensional magnetic resonance imaging to quantify effects of these treatments. Key Results Roots grew more slowly [root growth rate (mm h–1); decreased 50 %] with increased diameters [root diameter (mm); increased 15 %] in denser soils (1·7 vs. 1·5 g cm–3). Root response to gravity decreased 23 % with increased soil compaction, and tortuosity increased 10 % in mixed sand. Response to gravity increased 39 % and tortuosity decreased 3 % in sandy loam. After crossing a bilayered–soil interface, roots grew more slowly, similar to roots grown in soil with a bulk density of 1·64 g cm–3, whereas the actual experimental density was 1·48±0·02 g cm–3. Elongation rate and tortuosity were higher in Mix_low than in Loam_low. Conclusions The present study increases our existing knowledge of the influence of physical soil properties on root growth and presents new assays for studying root growth dynamics in non-transparent media. We found that root tortuosity is indicative of root path selection, because it could result from both mechanical deflection and

  10. A new Approach for Quantifying Root-Reinforcement of Streambanks: the RipRoot Model

    Science.gov (United States)

    Pollen, N. L.; Simon, A.

    2003-12-01

    Riparian vegetation plays an important role in controlling geotechnical and fluvial processes acting along and within streambanks through the binding effects of roots. Quantification of this mechanical effect is therefore essential to accurately model streambank stability. Until now, most attempts to include the effects of root reinforcement by riparian vegetation have used root-cohesion values estimated using the Wu et al. (1979) equation, requiring the tensile strengths and diameters of the roots crossing the potential shear-plane. However, the Wu et al. equation is a static model that assumes that all roots break, and that they all break simultaneously. Field observations and laboratory experiments have shown that in reality the roots do not all break simultaneously, and that the breaking of roots during mass failure is in fact a dynamic process. Static models such as the Wu et al. equation are therefore likely to produce overestimations of cohesion due to roots. As a response to this concern, a dynamic root reinforcement model (RipRoot) was developed, based on the concepts of fiber bundle models (FBM's) used in materials science. Within the model the root-soil system is loaded incrementally resulting in progressive root breaking and redistribution of stresses from the broken roots to the remaining intact roots in the soil matrix. The redistribution and loading process continues until either all of the roots have broken, or equilibrium is reached where the root network supports the driving force imposed on the bank. The increase in bank cohesion using the static Wu et al. equation are 18% to 38% higher than RipRoot for riparian tree species, including Black Willow, Sandbar Willow, Cottonwood, River Birch and Eastern Sycamore, and 49% higher for Switch Grass. These variations in cohesion values can have a significant impact on streambank Factor of Safety (Fs) values calculated using the Simon et al. (2000) bank-stability model. For example, a 3m high silt

  11. Modelling water uptake efficiency of root systems

    Science.gov (United States)

    Leitner, Daniel; Tron, Stefania; Schröder, Natalie; Bodner, Gernot; Javaux, Mathieu; Vanderborght, Jan; Vereecken, Harry; Schnepf, Andrea

    2016-04-01

    Water uptake is crucial for plant productivity. Trait based breeding for more water efficient crops will enable a sustainable agricultural management under specific pedoclimatic conditions, and can increase drought resistance of plants. Mathematical modelling can be used to find suitable root system traits for better water uptake efficiency defined as amount of water taken up per unit of root biomass. This approach requires large simulation times and large number of simulation runs, since we test different root systems under different pedoclimatic conditions. In this work, we model water movement by the 1-dimensional Richards equation with the soil hydraulic properties described according to the van Genuchten model. Climatic conditions serve as the upper boundary condition. The root system grows during the simulation period and water uptake is calculated via a sink term (after Tron et al. 2015). The goal of this work is to compare different free software tools based on different numerical schemes to solve the model. We compare implementations using DUMUX (based on finite volumes), Hydrus 1D (based on finite elements), and a Matlab implementation of Van Dam, J. C., & Feddes 2000 (based on finite differences). We analyse the methods for accuracy, speed and flexibility. Using this model case study, we can clearly show the impact of various root system traits on water uptake efficiency. Furthermore, we can quantify frequent simplifications that are introduced in the modelling step like considering a static root system instead of a growing one, or considering a sink term based on root density instead of considering the full root hydraulic model (Javaux et al. 2008). References Tron, S., Bodner, G., Laio, F., Ridolfi, L., & Leitner, D. (2015). Can diversity in root architecture explain plant water use efficiency? A modeling study. Ecological modelling, 312, 200-210. Van Dam, J. C., & Feddes, R. A. (2000). Numerical simulation of infiltration, evaporation and shallow

  12. 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.

  13. Tissue response to potential root-end filling materials in infected root canals.

    Science.gov (United States)

    Chong, B S; Ford, T R; Kariyawasam, S P

    1997-03-01

    The tissue responses to two potential root-end filling materials, a light-cured glass ionomer cement (Vitrebond) and a reinforced zinc oxide-eugenol cement (Kalzinol) were compared with that to amalgam. In 27 premolar teeth of beagle dogs (54 roots), a collection of endodontic pathogenic bacteria was first inoculated into the root canals to induce periapical lesions. On each root, an apicectomy was performed and root-end cavities prepared to receive fillings of each material. The teeth and surrounding jaw were removed after 8 weeks (24 roots) and 4 weeks (30 roots); and they were prepared for histological examination. The tissue response to amalgam fillings after 4 and 8 weeks was marked by moderate or severe inflammation on all roots, and extended > 0.5 mm in 10 out of 18 roots. In contrast, after 8 weeks, the majority of roots filled with Kalzinol showed little or moderate inflammation while the tissue response to Vitrebond was the best of the three materials, and was also less extensive. After 4 weeks, the overall best tissue response was with Kalzinol, followed closely by Vitrebond. The differences between materials for both time periods with either none or few inflammatory cells when compared with that with either moderate or severe inflammation were statistically significant (P inflammation or inflammation extending inflammation extending > 0.2 mm ( 0.5 mm) were statistically significant (P < 0.01). Both Vitrebond and Kalzinol have potential as root-end filling materials as the tissue response was considerably more favourable than that to amalgam.

  14. Mercury content of sprouts and harvested roots from treated sweet potato mother roots. [Ipomoea batatas

    Energy Technology Data Exchange (ETDEWEB)

    Huisingh, D.; Nielsen, L.W.

    1972-01-01

    Mercury containing fungicides have been used extensively for seed and root disease control, but data on the fate of the mercury (Hg) are scarce. Experiments were designed to see if Hg applied to propagative sweet potato roots increased the Hg-content of edible roots. Roots were treated with Semesan Bel(hydroxymercurinitrophenol + hydroxymercurichlorophenol), Mertect (Thiabendazole: 2-(4-Thiazolyl)-benzimidazole), or Botran (2,6-Dichloro-4-nitroanaline) at recommended rates or with water. Treated roots were bedded into sandy loam soil, and the plants were harvested at 2 and 3 months after bedding. Some sprouts transplanted at 2 months were grown to maturity, and the harvested roots were analyzed. Hg analyses were performed by flameless atomic absorption. Roots treated prior to planting with Semesan Bel, Mertect, Botran, and water contained 23.0, 0.05, 0.03 and 0.03 ..mu..g/g dry wt, respectively. At the 2-month harvest, the leaves and stems of the Semesan Bel-treated plants contained 5 times more Hg than those of the other treatments. By the 3-month harvest, the amount of Hg in plant leaves and stems from Hg-treated roots was 2 to 3 times that of the others. Fall harvested fleshy roots contained 0.03, 0.02, 0.03, and 0.03 ..mu..g/g dry wt Hg for the Semesan Bel, Mertect, Botran, and water treatments, respectively. This demonstrates that the Hg applied to the mother root was translocated to the new plant, but little if any was translocated to the new fleshy roots.

  15. How can science education foster students' rooting?

    Science.gov (United States)

    Østergaard, Edvin

    2015-06-01

    The question of how to foster rooting in science education points towards a double challenge; efforts to prevent (further) uprooting and efforts to promote rooting/re-rooting. Wolff-Michael Roth's paper discusses the uprooting/rooting pair of concepts, students' feeling of alienation and loss of fundamental sense of the earth as ground, and potential consequences for teaching science in a rooted manner. However, the argumentation raises a number of questions which I try to answer. My argumentation rests on Husserl's critique of science and the "ontological reversal", an ontological position where abstract models from science are considered as more real than the everyday reality itself, where abstract, often mathematical, models are taken to be the real causes behind everyday experiences. In this paper, measures towards an "ontological re-reversal" are discussed by drawing on experiences from phenomenon-based science education. I argue that perhaps the most direct and productive way of promoting rooting in science class is by intentionally cultivating the competencies of sensing and aesthetic experience. An aesthetic experience is defined as a precognitive, sensuous experience, an experience that is opened up for through sensuous perception. Conditions for rooting in science education is discussed against three challenges: Restoring the value of aesthetic experience, allowing time for open inquiry and coping with curriculum. Finally, I raise the question whether dimensions like "reality" or "nature" are self-evident for students. In the era of constructivism, with its focus on cognition and knowledge building, the inquiry process itself has become more important than the object of inquiry. I argue that as educators of science teachers we have to emphasize more explicitly "the nature of nature" as a field of exploration.

  16. Cold temperature delays wound healing in postharvest sugarbeet roots

    Science.gov (United States)

    Storage temperature affects the rate and extent of wound-healing in a number of root and tuber crops. The effect of storage temperature on wound-healing in sugarbeet (Beta vulgaris L.) roots, however, is largely unknown. Wound-healing of sugarbeet roots was investigated using surface-abraded roots s...

  17. Root bacterial endophytes alter plant phenotype, but not physiology

    DEFF Research Database (Denmark)

    Henning, Jeremiah A.; Weston, David J.; Pelletier, Dale A.;

    2016-01-01

    (root:shoot, biomass production, root and leaf growth rates) and physiological traits (chlorophyll content, net photosynthesis, net photosynthesis at saturating light-Asat, and saturating CO2-Amax). Overall, we found that bacterial root endophyte infection increased root growth rate up to 184% and leaf...

  18. [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.

  19. Pea-root exudates and their effect upon root-nodule bacteria

    NARCIS (Netherlands)

    Egeraat, van A.W.S.M.

    1972-01-01

    The main purpose of this investigation was to study the exudation (mechanism, sites) of various compounds by roots of pea seedlings in relation to the growth of Rhizobium leguminosarum.Chapter 1 gives a survey of the literature pertaining to plant-root exudates and their influence upon soil microorg

  20. Root system markup language: toward a unified root architecture description language.

    Science.gov (United States)

    Lobet, Guillaume; Pound, Michael P; Diener, Julien; Pradal, Christophe; Draye, Xavier; Godin, Christophe; Javaux, Mathieu; Leitner, Daniel; Meunier, Félicien; Nacry, Philippe; Pridmore, Tony P; Schnepf, Andrea

    2015-03-01

    The number of image analysis tools supporting the extraction of architectural features of root systems has increased in recent years. These tools offer a handy set of complementary facilities, yet it is widely accepted that none of these software tools is able to extract in an efficient way the growing array of static and dynamic features for different types of images and species. We describe the Root System Markup Language (RSML), which has been designed to overcome two major challenges: (1) to enable portability of root architecture data between different software tools in an easy and interoperable manner, allowing seamless collaborative work; and (2) to provide a standard format upon which to base central repositories that will soon arise following the expanding worldwide root phenotyping effort. RSML follows the XML standard to store two- or three-dimensional image metadata, plant and root properties and geometries, continuous functions along individual root paths, and a suite of annotations at the image, plant, or root scale at one or several time points. Plant ontologies are used to describe botanical entities that are relevant at the scale of root system architecture. An XML schema describes the features and constraints of RSML, and open-source packages have been developed in several languages (R, Excel, Java, Python, and C#) to enable researchers to integrate RSML files into popular research workflow.

  1. Deep rooting conferred by DEEPER ROOTING 1 enhances rice yield in paddy fields

    Science.gov (United States)

    Arai-Sanoh, Yumiko; Takai, Toshiyuki; Yoshinaga, Satoshi; Nakano, Hiroshi; Kojima, Mikiko; Sakakibara, Hitoshi; Kondo, Motohiko; Uga, Yusaku

    2014-01-01

    To clarify the effect of deep rooting on grain yield in rice (Oryza sativa L.) in an irrigated paddy field with or without fertilizer, we used the shallow-rooting IR64 and the deep-rooting Dro1-NIL (a near-isogenic line homozygous for the Kinandang Patong allele of DEEPER ROOTING 1 (DRO1) in the IR64 genetic background). Although total root length was similar in both lines, more roots were distributed within the lower soil layer of the paddy field in Dro1-NIL than in IR64, irrespective of fertilizer treatment. At maturity, Dro1-NIL showed approximately 10% higher grain yield than IR64, irrespective of fertilizer treatment. Higher grain yield of Dro1-NIL was mainly due to the increased 1000-kernel weight and increased percentage of ripened grains, which resulted in a higher harvest index. After heading, the uptake of nitrogen from soil and leaf nitrogen concentration were higher in Dro1-NIL than in IR64. At the mid-grain-filling stage, Dro1-NIL maintained higher cytokinin fluxes from roots to shoots than IR64. These results suggest that deep rooting by DRO1 enhances nitrogen uptake and cytokinin fluxes at late stages, resulting in better grain filling in Dro1-NIL in a paddy field in this study. PMID:24988911

  2. Redirection of auxin flow in Arabidopsis thaliana roots after infection by root-knot nematodes

    NARCIS (Netherlands)

    Kyndt, Tina; Goverse, Aska; Haegeman, Annelies; Warmerdam, Sonja; Wanjau, Cecilia; Jahani, Mona; Engler, Gilbert; Almeida Engler, De Janice; Gheysen, Godelieve

    2016-01-01

    Plant-parasitic root-knot nematodes induce the formation of giant cells within the plant root, and it has been recognized that auxin accumulates in these feeding sites. Here, we studied the role of the auxin transport system governed by AUX1/LAX3 influx proteins and different PIN efflux proteins dur

  3. Etiology of phomopsis root rot in soybean

    Directory of Open Access Journals (Sweden)

    Valéria Cecília Ghissi

    2014-09-01

    Full Text Available In a survey of damages caused by soybean root rot to crops in the south of Brazil for several years, a root rot caused by Phomopsis sp has been found with increasing frequency. The primary symptoms are seen when the main root is cut longitudinally, including the death of the wood which shows white coloration and well-defined black lines that do not have a defined format. Thus, based on similarity, it has been called geographic root rot due to its aspect resembling irregular lines that separate regions on a map. In isolations, colonies and alpha spores of Phomopsis have prevailed. Pathogenicity test was done by means of inoculation in the crown of plants cultivated in a growth chamber. The geographic symptoms were reproduced in plants and the fungus Phomopsis sp. was reisolated. In soybean stems naturally infected with pod and stem blight, geographic symptoms caused by Phomopsis phaseoli are found. To the known symptoms on stems, pods and grains, that of root rot caused by P. phaseoli is now added.

  4. Chronic nerve root entrapment: compression and degeneration

    Science.gov (United States)

    Vanhoestenberghe, A.

    2013-02-01

    Electrode mounts are being developed to improve electrical stimulation and recording. Some are tight-fitting, or even re-shape the nervous structure they interact with, for a more selective, fascicular, access. If these are to be successfully used chronically with human nerve roots, we need to know more about the possible damage caused by the long-term entrapment and possible compression of the roots following electrode implantation. As there are, to date, no such data published, this paper presents a review of the relevant literature on alternative causes of nerve root compression, and a discussion of the degeneration mechanisms observed. A chronic compression below 40 mmHg would not compromise the functionality of the root as far as electrical stimulation and recording applications are concerned. Additionally, any temporary increase in pressure, due for example to post-operative swelling, should be limited to 20 mmHg below the patient’s mean arterial pressure, with a maximum of 100 mmHg. Connective tissue growth may cause a slower, but sustained, pressure increase. Therefore, mounts large enough to accommodate the root initially without compressing it, or compliant, elastic, mounts, that may stretch to free a larger cross-sectional area in the weeks after implantation, are recommended.

  5. Computing Rooted and Unrooted Maximum Consistent Supertrees

    CERN Document Server

    van Iersel, Leo

    2009-01-01

    A chief problem in phylogenetics and database theory is the computation of a maximum consistent tree from a set of rooted or unrooted trees. A standard input are triplets, rooted binary trees on three leaves, or quartets, unrooted binary trees on four leaves. We give exact algorithms constructing rooted and unrooted maximum consistent supertrees in time O(2^n n^5 m^2 log(m)) for a set of m triplets (quartets), each one distinctly leaf-labeled by some subset of n labels. The algorithms extend to weighted triplets (quartets). We further present fast exact algorithms for constructing rooted and unrooted maximum consistent trees in polynomial space. Finally, for a set T of m rooted or unrooted trees with maximum degree D and distinctly leaf-labeled by some subset of a set L of n labels, we compute, in O(2^{mD} n^m m^5 n^6 log(m)) time, a tree distinctly leaf-labeled by a maximum-size subset X of L that all trees in T, when restricted to X, are consistent with.

  6. Protein synthesis in geostimulated root caps

    Science.gov (United States)

    Feldman, L. J.

    1982-01-01

    A study is presented of the processes occurring in the root cap of corn which are requisite for the formation of root cap inhibitor and which can be triggered or modulated by both light and gravity. The results of this study indicate the importance of protein synthesis for light-induced gravitropic bending in roots. Root caps in which protein synthesis is prevented are unable to induce downward bending. This suggests that light acts by stimulating proteins which are necessary for the translation of the gravitropic stimulus into a growth response (downward bending). The turnover of protein with time was also examined in order to determine whether light acts by stimulating the synthesis of unique proteins required for downward growth. It is found that auxin in combination with light allows for the translation of the gravitropic stimulus into a growth response at least in part through the modification of protein synthesis. It is concluded that unique proteins are stimulated by light and are involved in promoting the downward growth in roots which are responding to gravity.

  7. Differences in U root-to-shoot translocation between plant species explained by U distribution in roots

    Energy Technology Data Exchange (ETDEWEB)

    Straczek, Anne; Duquene, Lise [Belgium Nuclear Research Centre (SCK.CEN), Biosphere Impact Studies, Boeretang 200, 2400 Mol (Belgium); Wegrzynek, Dariusz [IAEA, Seibersdorf Laboratories, A-2444 Seibersdorf (Austria); Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow (Poland); Chinea-Cano, Ernesto [IAEA, Seibersdorf Laboratories, A-2444 Seibersdorf (Austria); Wannijn, Jean [Belgium Nuclear Research Centre (SCK.CEN), Biosphere Impact Studies, Boeretang 200, 2400 Mol (Belgium); Navez, Jacques [Royal Museum of Africa, Department of Geology, Leuvensesteenweg 13, 3080 Tervuren (Belgium); Vandenhove, Hildegarde, E-mail: hvandenh@sckcen.b [Belgium Nuclear Research Centre (SCK.CEN), Biosphere Impact Studies, Boeretang 200, 2400 Mol (Belgium)

    2010-03-15

    Accumulation and distribution of uranium in roots and shoots of four plants species differing in their cation exchange capacity of roots (CECR) was investigated. After exposure in hydroponics for seven days to 100 mumol U L{sup -1}, distribution of uranium in roots was investigated through chemical extraction of roots. Higher U concentrations were measured in roots of dicots which showed a higher CECR than monocot species. Chemical extractions indicated that uranium is mostly located in the apoplasm of roots of monocots but that it is predominantly located in the symplasm of roots of dicots. Translocation of U to shoot was not significantly affected by the CECR or distribution of U between symplasm and apoplasm. Distribution of uranium in roots was investigated through chemical extraction of roots for all species. Additionally, longitudinal and radial distribution of U in roots of maize and Indian mustard, respectively showing the lowest and the highest translocation, was studied following X-ray fluorescence (XRF) analysis of specific root sections. Chemical analysis and XRF analysis of roots of maize and Indian mustard clearly indicated a higher longitudinal and radial transport of uranium in roots of Indian mustard than in roots of maize, where uranium mostly accumulated in root tips. These results showed that even if CECR could partly explain U accumulation in roots, other mechanisms like radial and longitudinal transport are implied in the translocation of U to the shoot.

  8. Root-soil air gap and resistance to water flow at the soil-root interface of Robinia pseudoacacia.

    Science.gov (United States)

    Liu, X P; Zhang, W J; Wang, X Y; Cai, Y J; Chang, J G

    2015-12-01

    During periods of water deficit, growing roots may shrink, retaining only partial contact with the soil. In this study, known mathematical models were used to calculate the root-soil air gap and water flow resistance at the soil-root interface, respectively, of Robinia pseudoacacia L. under different water conditions. Using a digital camera, the root-soil air gap of R. pseudoacacia was investigated in a root growth chamber; this root-soil air gap and the model-inferred water flow resistance at the soil-root interface were compared with predictions based on a separate outdoor experiment. The results indicated progressively greater root shrinkage and loss of root-soil contact with decreasing soil water potential. The average widths of the root-soil air gap for R. pseudoacacia in open fields and in the root growth chamber were 0.24 and 0.39 mm, respectively. The resistance to water flow at the soil-root interface in both environments increased with decreasing soil water potential. Stepwise regression analysis demonstrated that soil water potential and soil temperature were the best predictors of variation in the root-soil air gap. A combination of soil water potential, soil temperature, root-air water potential difference and soil-root water potential difference best predicted the resistance to water flow at the soil-root interface.

  9. 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.

  10. 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.

  11. Untangling the effects of root age and tissue nitrogen on root respiration in Populus tremuloides at different nitrogen supply.

    Science.gov (United States)

    Ceccon, Christian; Tagliavini, Massimo; Schmitt, Armin Otto; Eissenstat, David M

    2016-05-01

    Root respiration is a major contributor to terrestrial carbon flux. Many studies have shown root respiration to increase with an increase in root tissue nitrogen (N) concentration across species and study sites. Studies have also shown that both root respiration and root N concentration typically decrease with root age. The effects of added N may directly increase respiration of existing roots or may affect respiration by shifting the age structure of a root population by stimulating growth. To the best of our knowledge, no study has ever examined the effect of added N as a function of root age on root respiration. In this study, root respiration of 13-year-old Populus tremuloides Michx. trees grown in the field and 1-year-old P. tremuloides seedlings grown in containers was analyzed for the relative influence of root age and root N concentration independent of root age on root respiration. Field roots were first tracked using root windows and then sampled at known age. Nitrogen was either applied or not to small patches beneath the windows. In a pot experiment, each plant was grown with its root system split between two separate pots and N was applied at three different levels, either at the same or at different rates between pots. Root N concentration ranged between 1.4 and 1.7% in the field experiment and 1.8 and 2.6% in the seedling experiment. We found that addition of N increased root N concentration of only older roots in the field but of roots of all ages in the potted seedlings. In both experiments, the age-dependent decline in root respiration was largely consistent, and could be explained by a negative power function. Respiration decreased ∼50% by 3 weeks of age. Although root age was the dominant factor affecting respiration in both experiments, in the field experiment, root N also contributed to root respiration independent of root age. These results add further insight into respiratory responses of roots to N addition and mechanisms underlying the

  12. The role of root hairs in cadmium acquisition by barley

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Ruilun; Li Huafen [Key Laboratory of Plant-Soil Interactions of the Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China); Jiang Rongfeng, E-mail: rfjiang@cau.edu.c [Key Laboratory of Plant-Soil Interactions of the Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China); Roemheld, Volker [Institute of Plant Nutrition, University of Hohenheim, D-70593 Stuttgart (Germany); Zhang Fusuo [Key Laboratory of Plant-Soil Interactions of the Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China); Zhao Fangjie [Soil Science Department, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ (United Kingdom)

    2011-02-15

    The role of root hairs in Cd acquisition from soil was investigated in three pot experiments using a root hairless mutant (bald root barley, brb) and its wild-type (WT) cultivar of barley (Hordeum vulgare). brb had significantly lower concentrations and lower total amounts of Cd in shoots than WT. The Cd uptake efficiency based on total root length was 8-45% lower in brb than in WT. The difference between brb and WT increased with increasing extractable Cd in soil under the experimental conditions used. Additions of phosphate to soil decreased Cd extractability. Both soil and foliar additions of phosphate decreased root length, and root hair formation in WT. These effects resulted in decreased Cd uptake with increasing P supply. Cd uptake in WT correlated significantly with root length, root hair length and density, and soil extractable Cd. Root hairs contribute significantly to Cd uptake by barley. - Research highlights: The Cd uptake efficiency was significantly lower in brb than in WT. Additions of phosphate to soil decreased Cd extractability and Cd uptake. Both soil and foliar additions of phosphate decreased root length, and root hair formation in WT. Root hairs contribute significantly to Cd uptake by barley. - The Cd uptake efficiency based on total root length was 8-45% lower in a barley root hairless mutant than in its wild-type, indicating an important role of root hairs in Cd acquisition.

  13. Nitrogenase Activity Associated with Halodule wrightii Roots.

    Science.gov (United States)

    Smith, G W; Hayasaka, S S

    1982-06-01

    Nitrogen fixation (acetylene reduction) associated with roots of the seagrass Halodule wrightii was measured offshore near Beaufort and Moorhead City, N.C. Rates of acetylene reduction were higher in aerobic than in anaerobic assays and were linear for up to 5 days. The temperature range for acetylene reduction was 15 to 35 degrees C with a maximum activity at 35 degrees C. Nitrogenase activity was shown to vary seasonally with highest activities occurring during warmer summer months (23 mug of N(2) fixed per m per day). At in situ temperature, nitrogenase activities associated with surface-sterilized and non-surface-sterilized roots were similar. One morphological bacterial type was isolated from surface-sterilized roots and identified as Klebsiella pneumoniae type 4B.

  14. Tree root systems and nutrient mobilization

    DEFF Research Database (Denmark)

    Boyle, Jim; Rob, Harrison; Raulund-Rasmussen, Karsten;

    Roots mobilize nutrients via deep penetration and rhizosphere processes inducing weathering of primary minerals. These contribute to C transfer to soils and to tree nutrition. Assessments of these characteristics and processes of root systems are important for understanding long-term supplies...... of nutrient elements essential for forest growth and resilience. Research and techniques have signifi cantly advanced since Olof Tamm’s 1934 base mineral index for Swedish forest soils, and basic nutrient budget estimates for whole-tree harvesting systems of the 1970s. Recent research in areas that include...... sometimes stored at depth. Other recent studies on potential release of nutrients due to chemical weathering indicate the importance of root access to deep soil layers. Release profi les clearly indicate depletion in the top layers and a much higher potential in B and C horizons. Review of evaluations...

  15. Aortic Root Enlargement or Sutureless Valve Implantation?

    Directory of Open Access Journals (Sweden)

    Nikolaos G. Baikoussis

    2016-11-01

    Full Text Available Aortic valve replacement (AVR in patients with a small aortic annulus is a challenging issue. The importance of prosthesis–patient mismatch (PPM post aortic valve replacement (AVR is controversial but has to be avoided. Many studies support the fact that PPM has a negative impact on short and long term survival. In order to avoid PPM, aortic root enlargement may be performed. Alternatively and keeping in mind that often some comorbidities are present in old patients with small aortic root, the Perceval S suturelles valve implantation could be a perfect solution. The Perceval sutureless bioprosthesis provides reasonable hemodynamic performance avoiding the PPM and providing the maximum of aortic orifice area. We would like to see in the near future the role of the aortic root enlargement techniques in the era of surgical implantation of the sutureless valve (SAVR and the transcatheter valve implantation (TAVI.

  16. Cryptographic Protocols Based on Root Extracting

    DEFF Research Database (Denmark)

    Koprowski, Maciej

    In this thesis we design new cryptographic protocols, whose security is based on the hardness of root extracting or more speci cally the RSA problem. First we study the problem of root extraction in nite Abelian groups, where the group order is unknown. This is a natural generalization of the...... construction based on root extracting. As an example of this, we modify Cramer-Shoup signature scheme such that it becomes a genericm algorithm. We discuss then implementing it in RSA groups without the original restriction that the modulus must be a product of safe primes. It can also be implemented in class......,  providing a currently acceptable level of security. This allows us to propose the rst practical blind signature scheme provably secure, without relying on heuristics called random oracle model (ROM). We obtain the protocol for issuing blind signatures by implementing our modi ed Fischlin's signing algorithm...

  17. Indução e cultivo in vitro de gemas adventícias em segmentos de epicótilo de laranja-azeda In vitro induction and culture of adventitious buds in epicotyl segments of sour orange

    Directory of Open Access Journals (Sweden)

    Rosely Pereira da Silva

    2008-10-01

    Full Text Available O objetivo deste trabalho foi avaliar a indução e a formação de gemas adventícias em explantes de laranja-azeda, pelo uso de fitorreguladores. Em experimentos de organogênese in vitro foram avaliados 6-benzilaminopurina (BAP, thidiazuron (TDZ e cinetina (CIN, em diferentes concentrações e sob duas condições de luminosidade; BAP e CIN combinados ou não com ácido naftalenoacético (ANA; e BAP e CIN isoladamente ou combinados entre si. Segmentos de epicótilo de 1 cm de comprimento, provenientes de plântulas de laranja-azeda germinadas in vitro, foram utilizados como explantes. Para induzir a formação de gemas, os segmentos foram cultivados em meio MT com ou sem adição de fitorreguladores. O material foi cultivado a 27ºC em ausência de luz por 30 dias, seguidos de fotoperíodo de 16 horas. O delineamento experimental foi inteiramente casualizado, com quatro ou cinco repetições, a depender do experimento e, cada repetição foi constituída de placa de Petri com 20 explantes. Após 60 ou 70 dias de cultivo foram avaliados o percentual de explantes responsivos e o número de gemas por explante. A adição de BAP ao meio de cultura, combinada ou não com ANA, e em combinações com CIN promovem melhor resposta organogênica.The objective of this work was to evaluate the induction and formation of adventitious buds in sour orange explants through the use of plant regulators. In vitro organogenesis experiments were conducted to evaluate the effect of BAP, TDZ, and KIN in different concentrations and under two light conditions; BAP and KIN, combined or not with NAA; BAP and KIN, separately or in combined concentrations. Sour orange epicotyl segments (1 cm length, from in vitro germinated plants, were used as explants. In order to induce bud formation, the explants were cultured in MT medium with or without the addition of plant regulators. The material was cultivated at 27ºC in the absence of light for 30 days, followed of culture

  18. Roots Air Management System with Integrated Expander

    Energy Technology Data Exchange (ETDEWEB)

    Stretch, Dale [Eaton Corporation, Menomonee Falls, WI (United States); Wright, Brad [Eaton Corporation, Menomonee Falls, WI (United States); Fortini, Matt [Eaton Corporation, Menomonee Falls, WI (United States); Fink, Neal [Ballard Power Systems, Burnaby, BC (Canada); Ramadan, Bassem [Kettering Univ., Flint, MI (United States); Eybergen, William [Eaton Corporation, Menomonee Falls, WI (United States)

    2016-07-06

    PEM fuel cells remain an emerging technology in the vehicle market with several cost and reliability challenges that must be overcome in order to increase market penetration and acceptance. The DOE has identified the lack of a cost effective, reliable, and efficient air supply system that meets the operational requirements of a pressurized PEM 80kW fuel cell as one of the major technological barriers that must be overcome. This project leveraged Roots positive displacement development advancements and demonstrated an efficient and low cost fuel cell air management system. Eaton built upon its P-Series Roots positive displacement design and shifted the peak efficiency making it ideal for use on an 80kW PEM stack. Advantages to this solution include: • Lower speed of the Roots device eliminates complex air bearings present on other systems. • Broad efficiency map of Roots based systems provides an overall higher drive cycle fuel economy. • Core Roots technology has been developed and validated for other transportation applications. Eaton modified their novel R340 Twin Vortices Series (TVS) Roots-type supercharger for this application. The TVS delivers more power and better fuel economy in a smaller package as compared to other supercharger technologies. By properly matching the helix angle with the rotor’s physical aspect ratio, the supercharger’s peak efficiency can be moved to the operating range where it is most beneficial for the application. The compressor was designed to meet the 90 g/s flow at a pressure ratio of 2.5, similar in design to the P-Series 340. A net shape plastic expander housing with integrated motor and compressor was developed to significantly reduce the cost of the system. This integrated design reduced part count by incorporating an overhung expander and motor rotors into the design such that only four bearings and two shafts were utilized.

  19. Root resorption during orthodontic tooth movements.

    Science.gov (United States)

    Ramanathan, C; Hofman, Z

    2009-12-01

    The aim of the study was to compare the extent of maxillary incisor root resorption during different orthodontic tooth movements using three different techniques, namely the basal intrusion arch, the three component arch, and levelling of the upper dental arch with the straightwire appliance. The radiographs of 49 subjects (20 males and 29 females) with a mean age of 14.5 years were taken at two time points: in groups 1 and 2 after the levelling phase and in group 3 immediately after placement of the archwire (T1) and in all groups after a period of 6 months (T2). The amount of root resorption of the central incisors was determined at T2. The average incisor resorption was different in the three groups, with group 2 (three component arch) showing greater resorption (0.46 mm) than groups 1 (basal arch) and 3 (straightwire) of 0.26 and 0.25 mm, respectively. Analysis of variance (ANOVA) demonstrated that differences in root resorption in the three groups were not significant. Wilcoxon paired test showed that the root resorption occurring between T1 and T2 in the three groups was not significant. There was also no significant difference among the rates of resorption in the three groups. Grouping the subjects on the basis of the extent of root resorption and the biomechanics used showed differences in the percentage of subjects with the least (resorption between the three groups. This again showed that the technique of three component intrusion arch resulted in the greatest increase in root resorption.

  20. LC/MS profiling of flavonoid glycoconjugates isolated from hairy roots, suspension root cell cultures and seedling roots of Medicago truncatula

    OpenAIRE

    Staszków, Anna; Swarcewicz, Barbara; Banasiak, Joanna; Muth, Dorota; Jasiński, Michał; Stobiecki, Maciej

    2011-01-01

    Hairy roots and suspension cell cultures are commonly used in deciphering different problems related to the biochemistry and physiology of plant secondary metabolites. Here, we address about the issue of possible differences in the profiles of flavonoid compounds and their glycoconjugates derived from various plant materials grown in a standard culture media. We compared profiles of flavonoids isolated from seedling roots, hairy roots, and suspension root cell cultures of a model legume plant...

  1. Effects of nutrition spatial heterogeneity on root traits and carbon usage by roots of Cercis chinensis seedlings in split root rooms

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In natural ecosystems, nutrition available for plants shows great spatial heterogeneity. Much is known about plant root responses to the spatial heterogeneity of nutrition, but little is known about carbon usage in roots in nutrition-deficient patches and its effect on root longevity. In this study, split-room boxes were used for culture of Cercis chinensis seedlings, and the small rooms were supplied with different nutrition levels. The number of the first-order roots in the rooms with nutrition supply was significantly higher than that in the rooms with deficient nutrition. Specific root length (SRL) of the first-order roots in the rooms with deficient nutrition reached its peak at day 64 after nutrition treatment. There was no significant SRL differences between the two order roots during the experiment. Biomass of the first-order roots in the rooms without nutrition supply was significantly less than that of the first-order roots in the rooms with nutrition supply from day 64 to 96. The total biomass of the lateral roots in the rooms without nu-trition supply decreased from day 64 to 96. The activities of the enzymes in roots in the rooms without nutrition supply increased and the activities of alkaline invertases in roots in the two sides of split box did not change significantly. The activities of the enzymes in roots in the rooms without nutrition supply increased gradually. These results suggest that nutrition spatial heterogeneity induced the changes in root traits and plants actively controlled carbon usage in roots in nutrition-deficient patches by regulating the activities of invertases and sucrose synthases, resulting in the reduction in carbon usage in the roots in nutrition-deficient patches.

  2. Root approach for estimation of statistical distributions

    Science.gov (United States)

    Bogdanov, Yu. I.; Bogdanova, N. A.

    2014-12-01

    Application of root density estimator to problems of statistical data analysis is demonstrated. Four sets of basis functions based on Chebyshev-Hermite, Laguerre, Kravchuk and Charlier polynomials are considered. The sets may be used for numerical analysis in problems of reconstructing statistical distributions by experimental data. Based on the root approach to reconstruction of statistical distributions and quantum states, we study a family of statistical distributions in which the probability density is the product of a Gaussian distribution and an even-degree polynomial. Examples of numerical modeling are given.

  3. Root approach for estimation of statistical distributions

    CERN Document Server

    Bogdanov, Yu I

    2014-01-01

    Application of root density estimator to problems of statistical data analysis is demonstrated. Four sets of basis functions based on Chebyshev-Hermite, Laguerre, Kravchuk and Charlier polynomials are considered. The sets may be used for numerical analysis in problems of reconstructing statistical distributions by experimental data. Based on the root approach to reconstruction of statistical distributions and quantum states, we study a family of statistical distributions in which the probability density is the product of a Gaussian distribution and an even-degree polynomial. Examples of numerical modeling are given. The results of present paper are of interest for the development of tomography of quantum states and processes.

  4. Tonoplast aquaporins facilitate lateral root emergence

    DEFF Research Database (Denmark)

    Reinhardt, Hagen; Hachez, Charles; Bienert, Manuela Désirée

    2016-01-01

    that, in Arabidopsis (Arabidopsis thaliana), the highly abundant tonoplast AQP isoforms AtTIP1;1, AtTIP1;2, and AtTIP2;1 facilitate the emergence of new lateral root primordia (LRPs). The number of lateral roots was strongly reduced in the triple tip mutant, whereas the single, double, and triple tip...... could be fully rescued by expressing AtTIP2;1 under its native promoter. We conclude that TIP isoforms allow the spatial and temporal fine-tuning of cellular water transport, which is critically required during the highly regulated process of LRP morphogenesis and emergence....

  5. Isolated root caps, border cells, and mucilage from host roots stimulate hyphal branching of the arbuscular mycorrhizal fungus, Gigaspora gigantea.

    Science.gov (United States)

    Nagahashi, Gerald; Douds, David D

    2004-09-01

    Unlike previous reports that have shown that water soluble and volatile compounds from roots or root exudates play an important role in precolonization events during arbuscular mycorrhizal (AM) fungus-host root interactions (Bécard & Piché 1989, Giovannetti et al. 1993), the results shown here deal with particulate and viscous fractions isolated from host roots. Root caps and a slow sedimenting particulate fraction (SSPF) were rapidly isolated and separated from Ri T-DNA transformed carrot roots (D. carota) grown in liquid culture. In addition, border cells (BC) and mucilage were isolated from aseptically grown corn seedlings (Zea mays). Root caps, SSPF (composed mainly of small root cap fragments and some BCs), BCs, and mucilage all had an associated AM fungus hyphal branching stimulator. Root caps stored for 5 d at 4 degrees C appeared to either synthesize or slowly release the branching stimulator. Also, isolated root caps from roots grown in the absence of P contained more branch stimulating activity than those isolated from roots grown in the presence of P. Although the branching stimulation activity in particulate fractions was low compared to that of the exudate, the particulate fractions can stick to the root surface at considerable distances from the root tip. This may be significant during the infection and colonization of host roots at sites far removed from the primary location of exudation.

  6. Tissue specific localization of root infection by fungal pathogens: role of root border cells.

    Science.gov (United States)

    Gunawardena, Uvini; Hawes, Martha C

    2002-11-01

    When roots of pea seedlings were inoculated uniformly with spores of Nectria haematocca or other pea pathogenic fungi, more than 90% developed lesions in the region of elongation within 3 days. More mature regions of most roots as well as the tip showed no visible signs of infection. Yet, microscopic observation revealed that 'mantles,' comprised of fungal hyphae intermeshed with populations of border cells, covered the tips of most roots. After physical detachment of the mantle, the underlying tip of most roots was found to be free of infection. Mantle-covered root tips did not respond to invasion of their border cells by activation of known defense genes unless there was invasion of the tip itself, as revealed by the presence of a lesion. Concomitant with the activation of defense genes was the induction of a cell-wall degrading enzyme whose expression is a marker for renewed production of border cells. Mantle formation did not occur in response to nonpathogens. The data are consistent with the hypothesis that border cells serve as a host-specific 'decoy' that protects root meristems by inhibiting fungal infection of the root tip.

  7. Hairy Root Induction in Helicteres isora L. and Production of Diosgenin in Hairy Roots.

    Science.gov (United States)

    Kumar, Vinay; Desai, Dnyanada; Shriram, Varsha

    2014-04-01

    Mature seeds of Helicteres isora L. were collected from seven geographical locations of Maharashtra and Goa (India) and evaluated for diosgenin (a bioactive steroidal sapogenin of prime importance) extraction and quantification. Chemotypic variations were evidenced with diosgenin quantity ranging from 33 μg g(-1) seeds (Osmanabad forests) to 138 μg g(-1) (Khopoli region). Nodal and leaf explants from in vitro-raised seedlings were used for callus and Agrobacterium-mediated transformation, respectively. Compact, hard, whitish-green callus (2.65 g explant(-1)) was obtained on MS + 13.32 μM BAP + 2.32 μM Kin after 30 days of inoculation. Various parameters including types of explant and Agrobacterium strain, culture density, duration of infection and various medium compositions were optimized for hairy root production. A. rhizogenes strain ATCC-15834 successfully induced hairy roots from leaf explants (1 cm(2)) with 42 % efficiency. Transgenic status of the roots was confirmed by PCR using rolB and VirD specific primers. Hairy roots showed an ability to synthesize diosgenin. Diosgenin yield was increased ~8 times in hairy roots and ~5 times in callus than the seeds of wild plants. Enhanced diosgenin content was associated with proline accumulation in hairy roots. This is the first report on induction of hairy roots in H. isora.

  8. [Morphology of wheat roots under low-phosphorus stress].

    Science.gov (United States)

    Sun, Haiguo; Zhang, Fusuo

    2002-03-01

    The morphology of root systems of different wheat (Triticum aestivum L.) genotypes under low-phosphorus stress were studied to determine the effects of external factors on components of root system and the early morphological indicators related to phosphorus efficiency. The number of root axes and the length of lateral root of P-deficient plant were significantly lower than those of P-sufficient plant. The length of root axis and root system, and the number of lateral roots were sharply increased under low-P stress. The number and length of root axis were significantly different under different levels of phosphorus supply and among different wheat genotypes under same phosphorus supply. This implied that the two traits (number and length of root axis) were controlled by genotype and external factors. The difference in the characteristics of lateral root of the given wheat genotypes was significant only between different levels of P supply. It showed that the traits of lateral root mainly depended on external factors. The length and number of root axis, root length, and root angle were significantly different among 6 wheat genotypes. There exited significant linear relationships between relative grain yield and the interaction of the morphological traits, and it implied that the traits could be used as early indicators of selecting high P-efficiency wheat varieties.

  9. 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.

  10. Adjustment of Forest Ecosystem Root Respiration as Temperature Warms

    Institute of Scientific and Technical Information of China (English)

    Andrew J. Burton; Jerry M. Melillo; Serita D. Frey

    2008-01-01

    Adjustment of ecosystem root respiration to warmer climatic conditions can alter the autotrophic portion of soil respiration and influence the amount of carbon available for biomass production. We examined 44 published values of annual forest root respiration and found an increase in ecosystem root respiration with increasing mean annual temperature (MAT),but the rate of this cross-ecosystem increase (Q10 = 1.6) is less than published values for short-term responses of root respiration to temperature within ecosystems (Q10 = 2-3). When specific root respiration rates and root biomass values were examined, there was a clear trend for decreasing root metabolic capacity (respiration rate at a standard temperature) with increasing MAT. There also were tradeoffs between root metabolic capacity and root system biomass, such that there were no instances of high growing season respiration rates and high root biomass occurring together. We also examined specific root respiration rates at three soil warming experiments at Harvard Forest, USA, and found decreases in metabolic capacity for roots from the heated plots. This decline could be due to either physiological acclimation or to the effects of co-occurring drier soils on the measurement date. Regardless of the cause, these findings clearly suggest that modeling efforts that allow root respiration to increase exponentially with temperature, with Qt0 values of 2 or more, may over-predict root contributions to ecosystem CO2 efflux for future climates and underestimate the amount of C available for other uses,including net primary productivity.

  11. Anchorage of mature conifers: resistive turning moment, root-soil plate geometry and root growth orientation.

    Science.gov (United States)

    Lundström, Tor; Jonas, Tobias; Stöckli, Veronika; Ammann, Walter

    2007-09-01

    Eighty-four mature Norway spruce (Picea abies L. Karst), silver fir (Abies alba Mill) and Scots pine (Pinus sylvestris L.) trees were winched over to determine the maximum resistive turning moment (M(a)) of the root-soil system, the root-soil plate geometry, the azimuthal orientation of root growth, and the occurrence of root rot. The calculation of M(a), based on digital image tracking of stem deflection, accounted not only for the force application and its changing geometry, but also for the weight of the overhanging tree, representing up to 42% of M(a). Root rot reduced M(a) significantly and was detected in 25% of the Norway spruce and 5% of the silver fir trees. Excluding trees with root rot, differences in M(a) between species were small and insignificant. About 75% of the variance in M(a) could be explained by one of the four variables--tree mass, stem mass, stem diameter at breast height squared times tree height, and stem diameter at breast height squared. Among the seven allometric variables assessed above ground, stem diameter at breast height best described the root-soil plate dimensions, but the correlations were weak and the differences between species were insignificant. The shape of the root-soil plate was well described by a depth-dependent taper model with an elliptical cross section. Roots displayed a preferred azimuthal orientation of growth in the axis of prevailing winds, and the direction of frequent weak winds matched the orientation of growth better than that of rare strong winds. The lack of difference in anchorage parameters among species probably reflects the similar belowground growth conditions of the mature trees.

  12. Rooting greenwood tip cuttings of several Populus clones hydroponically (hydroponic rooting of Populus cuttings)

    Energy Technology Data Exchange (ETDEWEB)

    Phipps, H.M.; Hansen, E.A.; Tolsted, D.N.

    1980-01-01

    Greenwood cuttings of several Populus clones were successfully rooted with a relatively simple hydroponic method. Indolebutyric acid and naphthaleneacetic acid at concentrations of 500 to 5000 ppM applied as a quick dip to the cutting bases, a complete nutrient solution at 20 to 40% of full strength, and a solution temperature between 27 and 30/sup 0/C generally produced the best rooting performance of most clones. Cuttings propagated by the hydroponic procedure rooted faster and generally outgrew those produced by a standard method after being transplanted to pots and grown in the greenhouse.

  13. Reproducible hairy root transformation and spot-inoculation methods to study root symbioses of pea

    Directory of Open Access Journals (Sweden)

    Clemow Scott R

    2011-12-01

    Full Text Available Abstract Pea has lagged behind other model legumes in the molecular study of nodulation and mycorrhizae-formation because of the difficulty to transform its roots and its poor growth on agar plates. Here we describe for pea 1 a transformation technique which permits the complementation of two known non-nodulating pea mutants, 2 a rhizobial inoculation method which allows the study of early cellular events giving rise to nodule primordia, and 3 a targeted fungal inoculation method which allows us to study short segments of mycorrhizal roots assured to be infected. These tools are certain to advance our knowledge of pea root symbioses.

  14. Methane and Root Dynamics in Arctic Soil

    DEFF Research Database (Denmark)

    D'Imperio, Ludovica

    on the global climate. We investigated two aspects of arctic ecosystem dynamics which are not well represented in climatic models: i) soil methane (CH4) oxidation in dry heath tundra and barren soils and ii) root dynamics in wetlands. Field measurements were carried out during the growing season in Disko Island...

  15. Aortic root replacement with a pulmonary autograft

    NARCIS (Netherlands)

    R.B. Hokken (Raymond)

    1997-01-01

    textabstractAortic valve disease in the pediatric age group is usually a consequence of congenital aortic stenosis, which may be isolated or may be a part of an anomaly of the left ventricular outflow tract or the aortic root. Management of these patients is difficult. Neonates and infants with seve

  16. The bifidogenic effect of Taraxacum officinale root.

    Science.gov (United States)

    Trojanová, I; Rada, V; Kokoska, L; Vlková, E

    2004-12-01

    The infusion of dandelion root (Taraxacum officinale) stimulated in vitro the growth of 14 strains of bifidobacteria. The utilization of oligofructans, glucose, fructose and total saccharides was determined by enzymatic and phenol-sulfuric methods. Dandelion oligofructans were important source of carbon and energy for bifidobacteria tested.

  17. Parameterizing the soil - water - plant root system

    NARCIS (Netherlands)

    Feddes, R.A.; Raats, P.A.C.

    2004-01-01

    Root water uptake is described from the local scale, to the field scale and to the regional and global scales. The local macroscopic model can be incorporated in Soil-Plant-Atmosphere Continuum (SPAC) numerical models, like the SWAP, HYSWASOR, HYDRUS, ENVIRO-GRO and FUSSIM models. These SPAC models

  18. Alkaloids from the Roots of Saccopetalum prolificum

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new alkaloid, named prolifine (1), was isolated along with four known alkaloids, liriodenine (2), 6-hydroxyonychine (3), isooncodine (4) and discretamine (5) from the roots of Saccopetalum prolificum. The structure of 1 was elucidated on the basis of spectroscopic and chemical methods.

  19. Phytochemical Investigations of Caesalpinia digyna Root

    Directory of Open Access Journals (Sweden)

    R. Srinivasan

    2011-01-01

    Full Text Available Phytochemical examination of petroleum ether extract of Caesalpinia digyna root resulted in the isolation of four compounds namely, friedelin, hexacosanoic acid, β-sitosterol and stigmasterol. These compounds have been characterized on basis of physical and spectral data. All the four compounds are being reported for the first time from this plant

  20. 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.

  1. Root resorption after orthodontic intrusion and extrusion:.

    NARCIS (Netherlands)

    Han, G.; Huang, S.; Hoff, J.W. Von den; Zeng, X.; Kuijpers-Jagtman, A.M.

    2005-01-01

    The aim of this investigation was to compare root resorption in the same individual after application of continuous intrusive and extrusive forces. In nine patients (mean age 15.3 years), the maxillary first premolars were randomly intruded or extruded with a continuous force of 100 cN for eight wee

  2. Occurrence of root parsley pathogens inhabiting seeds

    Directory of Open Access Journals (Sweden)

    Bogdan Nowicki

    2013-12-01

    Full Text Available The studies on root parsley pathogens inhabiting seeds were conducted during 1981-1988 and in 1993. Filter paper method with prefreezing and keeping under light was used. Each test sample comprised 500 seeds. Pathogenicity of collected fungal isolates was tested following two laboratory methods. 238 seed samples were studied. 18 fungal species were found but only 7 proved to be important pathogens of root parsley. The most common inhabitants of root parsley seeds were Alternaria spp. A.allernata occurred on 74,8% of seeds but only a few isolates showed to be slightly pathogenic while A.petroselini and A.radicina were higly pathogenic and inhabited 11,4 and 4,2% of seeds, respectively. The second group of important pathogens were species of Fusarium found on 3,9% of seeds. F.avenaceum dominated as it comprised 48% of Fusarium isolates, the next were as follow: F.culmorum - 20%, F.equiseti - 15%, F.solani - 8%, F.oxysporum - 7% and F.dimerum -2%. Some fungi like Botrytis cinerea, Septoria petroselini and Phoma spp. inhabited low number of seeds, respectively O,4; 0,5 and 0,8%, but they were highly pathogenic to root parsley. The fungi: Bipolaris sorokiniana, Drechslera biseptata, Stemphylium botryosum and Ulocludium consortiale showed slight pathogenicity. They were isolated from 3,8% of seeds.

  3. Pectate hydrolases of parsley (Petroselinum crispum) roots.

    Science.gov (United States)

    Flodrová, Dana; Dzúrovä, Mária; Lisková, Desana; Mohand, Fairouz Ait; Mislovicová, Danica; Malovícová, Anna; Voburka, Zdenek; Omelková, Jirina; Stratilová, Eva

    2007-01-01

    The presence of various enzyme forms with terminal action pattern on pectate was evaluated in a protein mixture obtained from parsley roots. Enzymes found in the soluble fraction of roots (juice) were purified to homogeneity according to SDS-PAGE, partially separated by preparative isoelectric focusing and characterized. Three forms with pH optima 3.6, 4.2 and 4.6 clearly preferred substrates with a lower degree of polymerization (oligogalacturonates) while the form with pH optimum 5.2 was a typical exopolygalacturonase [EC 3. 2.1.67] with relatively fast cleavage of polymeric substrate. The forms with pH optima 3.6, 4.2 and 5.2 were released from the pulp, too. The form from the pulp with pH optimum 4.6 preferred higher oligogalacturonates and was not described in plants previously. The production of individual forms in roots was compared with that produced by root cells cultivated on solid medium and in liquid one.

  4. An antileishmanial chalcone from Chinese licorice roots

    DEFF Research Database (Denmark)

    Christensen, S B; Ming, C; Andersen, L

    1994-01-01

    A bioassay guided fractionation of an extract of Chinese licorice roots led to the isolation of (E)-1-[2,4-dihydroxy-3-(3-methyl-2-butenyl)phenyl]-3-[4- hydroxy-3-(3-methyl-2-butenyl]phenyl-2-propen-1-one, which in vitro showed potent antileishmanial activity. In addition, the novel chalcone (E)-...

  5. Tapping Ancient Roots: Plaited Paper Baskets

    Science.gov (United States)

    Patrick, Jane

    2011-01-01

    With ancient roots, basket making has been practiced since the earliest civilizations, and according to textile experts, probably pre-dates pottery. This is partly conjecture since few baskets remain. It is through evidence found in clay impressions that the earliest baskets reveal themselves. Basically, basketry construction is like flat weaving.…

  6. Root canal cleaning through cavitation and microstreaming

    NARCIS (Netherlands)

    Verhaagen, B.

    2012-01-01

    We have investigated the flow from a needle using Computational Fluid Dynamics simulations and high-speed imaging experiments on sub-millimeter fluidic channels. These have shown that the flow is not effective in delivering the bleach near the bacteria, due to the complex geometry of the root canal.

  7. Quantum Dilogarithm Identities at Root of Unity

    CERN Document Server

    Ip, Ivan Chi-Ho

    2014-01-01

    We study the root of unity degeneration of cluster algebras and quantum dilogarithm identities. We prove identities for the cyclic dilogarithm associated with a mutation sequence of a quiver, and as a consequence new identities for the non-compact quantum dilogarithm at $b=1$.

  8. FiT gets CLEAN local roots

    Energy Technology Data Exchange (ETDEWEB)

    Meehan, Chris

    2012-07-01

    Feed-in tariffs are starting to take root in the US. While there is little to no hope of a national FiT policy, a growing number of cities, like Los Angeles, Gainesville, and Sacramento and states including California and Vermont are creating their own FiTs. (orig.)

  9. Boston: Community Schools from the Grass Roots

    Science.gov (United States)

    O'Neil, William F.

    1974-01-01

    In Boston, grass roots citizen pressure led to the formation of community schools to replace elementary schools. The community schools are operated by the Boston School Committee during the regular school day and by the Department of Public Facilities in the extended day and evening. (Author/DN)

  10. Dialectical roots for interest prohibition theory

    NARCIS (Netherlands)

    J.A. Bergstra

    2011-01-01

    It is argued that arguments for strict prohibition of interests must be based on the use of arguments from authority. This is carried out by first making a survey of so-called dialectical roots for interest prohibition and then demonstrating that for at least one important positive interest bearing

  11. Del Pezzo Moduli via Root Systems

    NARCIS (Netherlands)

    Colombo, E.; van Geemen, B.; Looijenga, E.J.N.

    2010-01-01

    Coble defined in his 1929 treatise invariants for cubic surfaces and quartic curves. We reinterpret these in terms of the root systems of type E6 and E7 that are naturally associated to these varieties, thereby giving some of his results a more intrinsic treatment. Our discussion is uniform for all

  12. Pharmacognostical Standardization of Tephrosia purpurea Pers Root.

    Science.gov (United States)

    Sandhya, S; Ventaka, Ramana K; Vinod, K R

    2010-07-01

    Wild Indigo or Purple Tephrosia or fish poison occurs throughout the Indian subcontinent. It is widely used in the treatment of inflammation, diabetes, rheumatism, asthma, diarrhoea and many other ailments. But so far the pharmacognostic standardization has not been reported for its proper identification. Hence the present study is a pharmacognosy work carried out for the root part. This may help in the identification of the plant species. A thin transverse section, powder microscopy, measurement of the dimensions of cell structures, fluorescence analysis and physico chemical parameters were conducted for the root. From the TS, the secondary xylem fibres and vessels were found to be the tissues of diagnostic importance. The xylem vessels were of two types: narrow and long; broad and short. The important characters in the powdered microscopy were vessel elements, fibres and xylem parenchyma cells. The different fluorescent light shades were obtained under short and long UV light for both powder as well as the extracts of the root. The proximate analysis values were also obtained in a satisfactory way. Combining all these data a suitable root profile for plant can be constructed which may help in the identification of quality of the plant part.

  13. Proofs of certain properties of irrational roots

    OpenAIRE

    Belbas, S. A.

    2009-01-01

    We give two elementary proofs, at a level understandable by students with only pre-calculus knowledge of Algebra, of the well known fact that an irreducible irrational n-th root of a positive rational number cannot be solution of a polynomial of degree less than n with rational coefficients. We also state and prove a few simple consequences.

  14. Quest for Continual Growth Takes Root

    Science.gov (United States)

    Surdey, Mary M.; Hashey, Jane M.

    2006-01-01

    In this article, the authors describe how the quest for continual growth has taken its root at Vestal Central School district. Located at the heart of upstate New York, educators at Vestal Central School district have created a spirit of "kaizen," a Japanese word meaning the relentless quest for continual improvement and higher-quality…

  15. Bacterial proteins pinpoint a single eukaryotic root.

    Science.gov (United States)

    Derelle, Romain; Torruella, Guifré; Klimeš, Vladimír; Brinkmann, Henner; Kim, Eunsoo; Vlček, Čestmír; Lang, B Franz; Eliáš, Marek

    2015-02-17

    The large phylogenetic distance separating eukaryotic genes and their archaeal orthologs has prevented identification of the position of the eukaryotic root in phylogenomic studies. Recently, an innovative approach has been proposed to circumvent this issue: the use as phylogenetic markers of proteins that have been transferred from bacterial donor sources to eukaryotes, after their emergence from Archaea. Using this approach, two recent independent studies have built phylogenomic datasets based on bacterial sequences, leading to different predictions of the eukaryotic root. Taking advantage of additional genome sequences from the jakobid Andalucia godoyi and the two known malawimonad species (Malawimonas jakobiformis and Malawimonas californiana), we reanalyzed these two phylogenomic datasets. We show that both datasets pinpoint the same phylogenetic position of the eukaryotic root that is between "Unikonta" and "Bikonta," with malawimonad and collodictyonid lineages on the Unikonta side of the root. Our results firmly indicate that (i) the supergroup Excavata is not monophyletic and (ii) the last common ancestor of eukaryotes was a biflagellate organism. Based on our results, we propose to rename the two major eukaryotic groups Unikonta and Bikonta as Opimoda and Diphoda, respectively.

  16. Bullying in nursing: roots, rationales, and remedies.

    Science.gov (United States)

    Szutenbach, Mary Pat

    2013-01-01

    Bullying and incivility are sadly, far too common in today's healthcare workplaces. This article reviews early to current literature, identifies types of bullying, offers four root causes, and suggests responses to impact these causes using Gibbs' Reflective Cycle, biblical Scripture, and an allegory "How to Swim with Sharks."

  17. Plant Hormones: How They Affect Root Formation.

    Science.gov (United States)

    Reinhard, Diana Hereda

    This science study aid, produced by the U.S. Department of Agriculture, includes a series of plant rooting activities for secondary science classes. The material in the pamphlet is written for students and includes background information on plant hormones, a vocabulary list, and five learning activities. Objectives, needed materials, and…

  18. Nodal distances for rooted phylogenetic trees.

    Science.gov (United States)

    Cardona, Gabriel; Llabrés, Mercè; Rosselló, Francesc; Valiente, Gabriel

    2010-08-01

    Dissimilarity measures for (possibly weighted) phylogenetic trees based on the comparison of their vectors of path lengths between pairs of taxa, have been present in the systematics literature since the early seventies. For rooted phylogenetic trees, however, these vectors can only separate non-weighted binary trees, and therefore these dissimilarity measures are metrics only on this class of rooted phylogenetic trees. In this paper we overcome this problem, by splitting in a suitable way each path length between two taxa into two lengths. We prove that the resulting splitted path lengths matrices single out arbitrary rooted phylogenetic trees with nested taxa and arcs weighted in the set of positive real numbers. This allows the definition of metrics on this general class of rooted phylogenetic trees by comparing these matrices through metrics in spaces M(n)(R) of real-valued n x n matrices. We conclude this paper by establishing some basic facts about the metrics for non-weighted phylogenetic trees defined in this way using L(p) metrics on M(n)(R), with p [epsilon] R(>0).

  19. REAL ROOT ISOLATION OF SPLINE FUNCTIONS

    Institute of Scientific and Technical Information of China (English)

    Renhong Wang; Jinming Wu

    2008-01-01

    In this paper,we propose an algorithm for isolating real roots of a given univariate spline function,which is based on the use of Descartes' rule of signs and de Casteljau algorithm.Numerical examples illustrate the flexibility and effectiveness of the algorithm.

  20. Damage to root dentin during retreatment procedures

    NARCIS (Netherlands)

    Shemesh, H.; Roeleveld, A.C.; Wesselink, P.R.; Wu, M.K.

    2011-01-01

    Introduction: The aim of this study was to explore the influence of retreatment procedures on the appearance of defects on the root canal walls. Methods: Two hundred mandibular premolars were divided into 4 groups. One group was left unprepared. The rest of the teeth were prepared with ProTaper file

  1. QTL Information Table: 121 [Q-TARO

    Lifescience Database Archive (English)

    Full Text Available Morphological trait Root adventitious root number(flooding) Mixture C)Interval DHL ...ndidate genes for rice root growth under flooding and upland conditions. Yi Chuan Xue Bao 33, 141-151. ...

  2. Seasonal changes of whole root system conductance by a drought-tolerant grape root system.

    Science.gov (United States)

    Alsina, Maria Mar; Smart, David R; Bauerle, Taryn; de Herralde, Felicidad; Biel, Carme; Stockert, Christine; Negron, Claudia; Save, Robert

    2011-01-01

    The role of root systems in drought tolerance is a subject of very limited information compared with above-ground responses. Adjustments to the ability of roots to supply water relative to shoot transpiration demand is proposed as a major means for woody perennial plants to tolerate drought, and is often expressed as changes in the ratios of leaf to root area (A(L):A(R)). Seasonal root proliferation in a directed manner could increase the water supply function of roots independent of total root area (A(R)) and represents a mechanism whereby water supply to demand could be increased. To address this issue, seasonal root proliferation, stomatal conductance (g(s)) and whole root system hydraulic conductance (k(r)) were investigated for a drought-tolerant grape root system (Vitis berlandieri×V. rupestris cv. 1103P) and a non-drought-tolerant root system (Vitis riparia×V. rupestris cv. 101-14Mgt), upon which had been grafted the same drought-sensitive clone of Vitis vinifera cv. Merlot. Leaf water potentials (ψ(L)) for Merlot grafted onto the 1103P root system (-0.91±0.02 MPa) were +0.15 MPa higher than Merlot on 101-14Mgt (-1.06±0.03 MPa) during spring, but dropped by approximately -0.4 MPa from spring to autumn, and were significantly lower by -0.15 MPa (-1.43±0.02 MPa) than for Merlot on 101-14Mgt (at -1.28±0.02 MPa). Surprisingly, g(s) of Merlot on the drought-tolerant root system (1103P) was less down-regulated and canopies maintained evaporative fluxes ranging from 35-20 mmol vine(-1) s(-1) during the diurnal peak from spring to autumn, respectively, three times greater than those measured for Merlot on the drought-sensitive rootstock 101-14Mgt. The drought-tolerant root system grew more roots at depth during the warm summer dry period, and the whole root system conductance (k(r)) increased from 0.004 to 0.009 kg MPa(-1) s(-1) during that same time period. The changes in k(r) could not be explained by xylem anatomy or conductivity changes of individual root

  3. Seasonal changes of whole root system conductance by a drought-tolerant grape root system

    Science.gov (United States)

    Alsina, Maria Mar; Smart, David R.; Bauerle, Taryn; de Herralde, Felicidad; Biel, Carme; Stockert, Christine; Negron, Claudia; Save, Robert

    2011-01-01

    The role of root systems in drought tolerance is a subject of very limited information compared with above-ground responses. Adjustments to the ability of roots to supply water relative to shoot transpiration demand is proposed as a major means for woody perennial plants to tolerate drought, and is often expressed as changes in the ratios of leaf to root area (AL:AR). Seasonal root proliferation in a directed manner could increase the water supply function of roots independent of total root area (AR) and represents a mechanism whereby water supply to demand could be increased. To address this issue, seasonal root proliferation, stomatal conductance (gs) and whole root system hydraulic conductance (kr) were investigated for a drought-tolerant grape root system (Vitis berlandieri×V. rupestris cv. 1103P) and a non-drought-tolerant root system (Vitis riparia×V. rupestris cv. 101-14Mgt), upon which had been grafted the same drought-sensitive clone of Vitis vinifera cv. Merlot. Leaf water potentials (ψL) for Merlot grafted onto the 1103P root system (–0.91±0.02 MPa) were +0.15 MPa higher than Merlot on 101-14Mgt (–1.06±0.03 MPa) during spring, but dropped by approximately –0.4 MPa from spring to autumn, and were significantly lower by –0.15 MPa (–1.43±0.02 MPa) than for Merlot on 101-14Mgt (at –1.28±0.02 MPa). Surprisingly, gs of Merlot on the drought-tolerant root system (1103P) was less down-regulated and canopies maintained evaporative fluxes ranging from 35–20 mmol vine−1 s−1 during the diurnal peak from spring to autumn, respectively, three times greater than those measured for Merlot on the drought-sensitive rootstock 101-14Mgt. The drought-tolerant root system grew more roots at depth during the warm summer dry period, and the whole root system conductance (kr) increased from 0.004 to 0.009 kg MPa−1 s−1 during that same time period. The changes in kr could not be explained by xylem anatomy or conductivity changes of individual root

  4. Electrical Imaging of Roots and Trunks

    Science.gov (United States)

    Al Hagrey, S.; Werban, U.; Meissner, R.; Ismaeil, A.; Rabbel, W.

    2005-05-01

    We applied geoelectric and GPR techniques to analyze problems of botanical structures and even processes, e.g., mapping root zones, internal structure of trunks, and water uptake by roots. The dielectric nature of root zones and trunks is generally a consequence of relatively high moisture content. The electric method, applied to root zones, can discriminate between old, thick, isolated roots (high resistivity) and the network of young, active, and hydraulically conductive zones (low resistivity). Both types of roots show low radar velocity and a strong attenuation caused by the dominant effect of moisture (high dielectric constant) on the electromagnetic wave propagation. Single root branches could be observed in radargrams by their reflection and diffraction parabolas. We have perfected the inversion method for perfect and imperfect cylindrical objects, such as trunks, and developed a new multielectrodes (needle or gel) ring array for fast applications on living trees and discs. Using synthetic models we tested the technique successfully and analyzed it as a function of total electrode number and configuration. Measurements at a trunk show a well established inverse relationship between the imaged resistivity and the moisture content determined from cores. The central resistivity maximum of healthy trees strongly decreases toward the rim. This agrees with the moisture decrease to the outside where active sap flow processes take place. Branching, growth anomalies (new or old shoots) and meteorological effects (sunshine and wind direction) lead to deviations of the concentric electric structure. The strongest anomalies are related to infections causing wet, rotting spots or cavities. The heartwood resistivity is highest in olive and oak trunks, intermediate in young fruit trees and lowest in cork oak trunks that are considered to be anomalously wet. Compared to acoustic tomography our electric technique shows a better resolution in imaging internal ring structures

  5. On Integrable Roots in Split Lie Triple Systems

    Institute of Scientific and Technical Information of China (English)

    A.J.CALDER(O)N MART(I)N

    2009-01-01

    We focus on the notion of an integrable root in the framework of split Lie triple systems T with a coherent 0-root space. As a main result, it is shown that if T has all its nonzero roots integrable, then its standard embedding is a split Lie algebra having all its nonzero roots integrable. As a consequence, a local finiteness theorem for split Lie triple systems, saying that whenever all nonzero roots of T are integrable then T is locally finite, is stated. Finally, a classification theorem for split simple Lie triple systems having all its nonzero roots integrable is given.

  6. External root resorption: Different etiologies explained from the composition of the human root-close periodontal membrane

    Directory of Open Access Journals (Sweden)

    Inger Kjaer

    2013-01-01

    Full Text Available Introduction: This paper summarizes different conditions, which have a well-known influence on the resorption of tooth roots. It also highlights factors important for individual susceptibility to root resorption. Furthermore, the paper focuses on idiopathic root resorption where the provoking factor is not known. The Hypothesis: The several different disturbances causing root resorption can be either orthodontically provoked or acquired by trauma, virus or congenital diseases. It is presumed that all these conditions lead to inflammatory processes in the three main tissue layers, comprising the peri-root sheet. Evaluation of the Hypothesis: This paper explains how different etiologies behind root resorption and how different phenotypic traits in root resorption can be understood from immunohistochemical studies of the human periodontal membrane close to the root and thus, gain a new understanding of the phenomenon of root resorption.

  7. 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

  8. Root-soil friction: quantification provides evidence for measurable benefits for manipulation of root-tip traits.

    Science.gov (United States)

    McKenzie, Blair M; Mullins, Christopher E; Tisdall, Judith M; Bengough, A Glyn

    2013-06-01

    To penetrate soil, a root requires pressure both to expand the cavity it is to occupy, σn , and to overcome root-soil friction, σf . Difficulties in estimating these two pressures independently have limited our ability to estimate the coefficient of soil-root friction, μsr . We used a rotated penetrometer probe, of similar dimensions to a root, and for the first time entering the soil at a similar rate to a root tip, to estimate σn . Separately we measured root penetration resistance (PR) Qr . Root PR was between two to four times σn . We estimated that the coefficient of root-soil friction (μsr ) was 0.21-0.26, based on the geometry of the root tip. This is slightly larger than the 0.05-0.15 characteristic of boundary lubricants. Scanning electron microscopy showed that turgid border cells lined the root channel, supporting our hypothesis that the lubricant consisted of mucilage sandwiched between border cells and the surface of the root cap and epidermis. This cell-cell lubrication greatly decreased the friction that would otherwise be experienced had the surface of the root proper slid directly past unlubricated soil particles. Because root-soil friction can be a substantial component of root PR, successful manipulation of friction represents a promising opportunity for improving plant performance.

  9. Root Induced Heterogeneity In Agricultural Soils

    Science.gov (United States)

    Gomes, C.; Gabai, R.; Weisbrod, N.; Furman, A.

    2012-12-01

    In this study we investigate the role of plant induced heterogeneity on water dynamics in agricultural soils. We conducted three experiments in two sites (one still ongoing) in which a trench was excavated in the root zone of an orchard and the subsurface, to a depth of over 1 m, was instrumented in high resolution with water content, water potential and temperature sensors. High temporal resolution monitoring of soil state was carried for over a year, period that included natural (Mediterranean) climate boundary forcing. In addition, sprinkler, flood, and spray irrigation boundary conditions were forced for short time periods to explore the infiltration process under these conditions. One site was an Avocado orchard planted in red sandy soil while the other, still on-going, is in a grape vineyards irrigated by tap and treated wastewater, planted over alluvial clayey soil. In the vineyard, we are comparing soil irrigated with fresh water to soil irrigated with treated waste water for more than 10 years. Our preliminary results indicate several interesting phenomena. First, the role of plant roots is clearly seen as the major roots act as a conduit for water (and solute), providing a fast bypass of the upper soil. Further, we identified different regions of the subsurface that apparently were of the same texture, but in practice presented very different hydraulic properties. Second, the role of these roots depends on the boundary conditions. That is, the root bypass acts differently when soil is flooded than when flow is strictly unsaturated. As expected, simulation of the experimental results show good fit only if the domain heterogeneity of soil properties was incorporated. Results for the clayey soils were not available at time of abstract submission.

  10. Root canal filling using Resilon: a review.

    LENUS (Irish Health Repository)

    Shanahan, D J

    2011-07-01

    Root canal treatment is achieved by chemo-mechanical debridement of the root canal system followed by filling. The filling material \\'entombs\\' residual bacteria and acts as a barrier which prevents the entrance of oral microorganisms and reinfection of the root canal system through microleakage. However, filling with contemporary root filling materials such as gutta-percha offers limited long-term resistance to microorganisms; as a result other materials such as Resilon have been investigated as alternatives. The aim of this review was to analyse the literature to consider whether Resilon is a suitable root canal filling material. A MEDLINE and Cochrane library search including various keyword searches identified several papers which investigated or discussed Resilon or RealSeal\\/Epiphany. Analysis of the literature demonstrated that the bulk of the literature is in vitro in nature, based largely on leakage-type studies, and demonstrates a wide variety of methodologies with conflicting findings; as a result meaningful conclusions are difficult. Within the limit of these in vitro studies Resilon appears to perform adequately in comparison to gutta-percha, however, as a result of the questionable merit of such studies, it cannot presently be considered an evidence-based alternative to the current gold standard gutta-percha. It is imperative that before Resilon is considered as a replacement material, a better understanding of the physical properties of the resin sealer and the reality of the adhesive \\'monoblock\\' are elucidated. The literature also demonstrates a paucity of quality long-term clinical outcome studies which will need to be addressed before firm conclusions can be reached.

  11. Root cap-dependent gravitropic U-turn of maize root requires light-induced auxin biosynthesis via the YUC pathway in the root apex

    Science.gov (United States)

    Suzuki, Hiromi; Yokawa, Ken; Nakano, Sayuri; Yoshida, Yuriko; Fabrissin, Isabelle; Okamoto, Takashi; Baluška, František; Koshiba, Tomokazu

    2016-01-01

    Gravitropism refers to the growth or movement of plants that is influenced by gravity. Roots exhibit positive gravitropism, and the root cap is thought to be the gravity-sensing site. In some plants, the root cap requires light irradiation for positive gravitropic responses. However, the mechanisms regulating this phenomenon are unknown. We herein report that maize roots exposed to white light continuously for ≥1–2h show increased indole-3-acetic acid (IAA) levels in the root tips, especially in the transition zone (1–3mm from the tip). Treatment with IAA biosynthesis inhibitors yucasin and l-kynurenine prevented any increases in IAA content and root curvature under light conditions. Analyses of the incorporation of a stable isotope label from tryptophan into IAA revealed that some of the IAA in roots was synthesized in the root apex. Furthermore, Zmvt2 and Zmyuc gene transcripts were detected in the root apex. One of the Zmyuc genes (ZM2G141383) was up-regulated by light irradiation in the 0–1mm tip region. Our findings suggest that IAA accumulation in the transition zone is due to light-induced activation of Zmyuc gene expression in the 0–1mm root apex region. Light-induced changes in IAA levels and distributions mediate the maize root gravitropic U-turn. PMID:27307546

  12. 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.

  13. Research on the Slope Protection Mechanism of Roots

    Directory of Open Access Journals (Sweden)

    Juan Wan

    2013-08-01

    Full Text Available This study aims to investigate the slope protection mechanism of roots. In ecological slope protection, plant roots can fix soil and protect slop through biological and mechanical action. However, previous studies on the slope protection mechanism are still not deep enough and inadequate. By taking four kinds of typical plant roots along Wu-Shen Expressway as the research object, through the indoor tensile test and root morphology observation analysis, the tensile strength and ultimate tension were studied and the influence to the stability of the slope was discussed in this study. The results show that the mean ultimate tension of roots is 7.19~29.96 N. The mean tension of shrub roots is 2~4 times greater than that of herb roots. The ultimate tension of the same plant roots increases with the diameter significantly. To the range of improvement, Shrub roots exceed herb ones. It also indicates that the mean tensile strength of roots are 24.48~74.25 MPa. Compared with the steel HRB235, the tensile strength of herb roots is as great as 1/5~1/3, while Shrub roots is about 1/10~1/5. The slope stability coefficient with plant growing is a positive correlation with roots tension and root number through the sliding surface and is a negative correlation with plants weight. In addition, the slope stability coefficient is related to plant density and root morphology. The test results demonstrate that the roots tension with acute angle or right angle to the landslide surface and the roots shear stiffness with obtuse angle can improve the performance of slope’s anti-slide. Four kinds of plants can improve the stability coefficient of shallow soil. As for the slope protection effect, herbage is superior to shrub. In general, grass-shrub mixed community is the ideal system for slope protection.

  14. Root traits contributing to plant productivity under drought

    Directory of Open Access Journals (Sweden)

    Louise eComas

    2013-11-01

    Full Text Available Geneticists and breeders are positioned to breed plants with root traits that improve productivity under drought. However, a better understanding of root functional traits and how traits are related to whole plant strategies to increase crop productivity under different drought conditions is needed. Root traits associated with maintaining plant productivity under drought include small fine root diameters, long specific root length (SRL, and considerable root length density, especially at depths in soil with available water. In environments with late season water deficits, small xylem diameters in targeted seminal roots save soil water deep in the soil profile for use during crop maturation and result in improved yields. Capacity for deep root growth and large xylem diameters in deep roots may also improve root acquisition of water when ample water at depth is available. Xylem pit anatomy that makes xylem less ‘leaky’ and prone to cavitation warrants further exploration holding promise that such traits may improve plant productivity in water-limited environments without negatively impacting yield under adequate water conditions. Rapid resumption of root growth following soil rewetting may improve plant productivity under episodic drought. Genetic control of many of these traits through breeding appears feasible. Several recent reviews have covered methods for screening root traits but an appreciation for the complexity of root systems (e.g. functional differences between fine and coarse roots needs to be paired with these methods to successfully identify relevant traits for crop improvement. Screening of root traits at early stages in plant development can proxy traits at mature stages but verification is needed on a case by case basis that traits are linked to increased crop productivity under drought. Examples in lesquerella (Physaria and rice (Oryza show approaches to phenotyping of root traits and current understanding of root trait

  15. Root traits contributing to plant productivity under drought.

    Science.gov (United States)

    Comas, Louise H; Becker, Steven R; Cruz, Von Mark V; Byrne, Patrick F; Dierig, David A

    2013-11-05

    Geneticists and breeders are positioned to breed plants with root traits that improve productivity under drought. However, a better understanding of root functional traits and how traits are related to whole plant strategies to increase crop productivity under different drought conditions is needed. Root traits associated with maintaining plant productivity under drought include small fine root diameters, long specific root length, and considerable root length density, especially at depths in soil with available water. In environments with late season water deficits, small xylem diameters in targeted seminal roots save soil water deep in the soil profile for use during crop maturation and result in improved yields. Capacity for deep root growth and large xylem diameters in deep roots may also improve root acquisition of water when ample water at depth is available. Xylem pit anatomy that makes xylem less "leaky" and prone to cavitation warrants further exploration holding promise that such traits may improve plant productivity in water-limited environments without negatively impacting yield under adequate water conditions. Rapid resumption of root growth following soil rewetting may improve plant productivity under episodic drought. Genetic control of many of these traits through breeding appears feasible. Several recent reviews have covered methods for screening root traits but an appreciation for the complexity of root systems (e.g., functional differences between fine and coarse roots) needs to be paired with these methods to successfully identify relevant traits for crop improvement. Screening of root traits at early stages in plant development can proxy traits at mature stages but verification is needed on a case by case basis that traits are linked to increased crop productivity under drought. Examples in lesquerella (Physaria) and rice (Oryza) show approaches to phenotyping of root traits and current understanding of root trait genetics for breeding.

  16. Temperature variation on root surface with three root-end cavity preparation techniques

    Directory of Open Access Journals (Sweden)

    Bodrumlu Emre

    2013-01-01

    Full Text Available Introduction. Thermal changes can occur on the external root surface when root-end cavity preparation is performed, which may damage periodontal ligament cells and alveolar bone. Objective. The purpose of this study was to evaluate the temperature changes during preparation of the root-end cavities at 1 and 3 mm to the sectioned apical root surfaces when either tungsten carbide round bur, diamond round bur or ultrasonic diamond tip was used. Methods. Root-end resection was performed at 90° to the long axis of the root, 3 mm from the apex. Specimens were randomly divided into three groups of 12 teeth each for three different root-end cavity preparation techniques to be used, i.e. tungsten carbide bur, diamond bur and ultrasonic diamond retro tip. Thermocouples were used to measure temperature changes at 1 mm (T1 and 3 mm (T2 to the cutting plane during the preparations. Results. For T1, the lowest and the highest mean temperature increases of 3.53°C and 4.34°C were recorded for the carbide and diamond burs, respectively. For T2, the lowest and the highest mean temperature increases of 2.62°C and 4.39°C where recorded for the carbide and diamond burs, respectively. The mean temperatures with the ultrasonic tip were 3.68 and 3.04 ºC at T1 and T2 region, respectively. For root-end preparation, the ultrasonic preparation technique took the shortest preparation time (10.25 sec and the diamond bur took the longest time (28.17 sec. Conclusion. Ultrasonic retro tips and burs caused temperature to rise from 2.62° to 4.39°C, and these rises were within safety levels.

  17. Amyloplast Distribution Directs a Root Gravitropic Reaction

    Science.gov (United States)

    Kordyum, Elizabeth

    Immobile higher plants are oriented in the gravitational field due to gravitropim that is a physiological growth reaction and consists of three phases: reception of a gravitational signal by statocytes, its transduction to the elongation zone, and finally the organ bending. As it is known, roots are characterized with positive gravitropism, i. e. they grow in the direction of a gravitational vector, stems - with negative gravitropism, i. e. they grow in the direction opposite to a gravitational vector. According to the Nemec’s and Haberlandt’s starch-statolith hypothesis, amyloplasts in diameter of 1.5 - 3 μ in average, which appear to act as gravity sensors and fulfill a statolythic function in the specialized graviperceptive cells - statocytes, sediment in the direction of a gravitational vector in the distal part of a cell, while a nucleus is in the proximal one. There are reasonable data that confirm the amyloplasts-statoliths participation in gravity perception: 1) correlation between the statoliths localization and the site of gravity sensing, 2) significant redistribution (sedimentation) of amyloplasts in statocytes under gravistimulation in comparison with other cell organelles, 3) root decreased ability to react on gravity under starch removal from amyloplasts, 4) starchless Arabidopsis thaliana mutants are agravitropic, 5) amyloplasts-statoliths do not sediment in the absence of the gravitational vector and are in different parts or more concentrated in the center of statocytes. Plant tropisms have been intensively studied for many decades and continue to be investigated. Nevertheless, the mechanisms by which plants do so is still not clearly explained and many questions on gravisensing and graviresponse remain unanswered. Even accepted hypotheses are now being questioned and recent data are critically evaluated. Although the available data show the Ca2+ and cytoskeleton participation in graviperception and signal transduction, the clear evidence

  18. Assessment of the wetting behavior of three different root canal sealers on root canal dentin

    Directory of Open Access Journals (Sweden)

    Muralidhar Tummala

    2012-01-01

    Full Text Available Aim: The objective of the present study was to evaluate and compare the wetting behavior of three different root canal sealers on the root canal dentin surface treated with irrigants and their combination. Materials and Methods: Decoronation and apical third resections of 27 extracted single-rooted human mandibular premolars were done. The roots were then split longitudinally into two halves, and randomly assigned into three treatment groups (n=18. The root dentin surfaces in Group1, Group 2 and Group 3 were treated with 17% ethylene diamine tetra acetic acid (EDTA, 3% sodium hypochlorite (NaOCl and combination of 17% EDTA and 3% NaOCl, respectively. Each group was subdivided into three subgroups of 6 specimens each, depending on the the sealer used, i.e. sub group A. zinc oxide (ZnOE, sub group B. AH plus, subgroup C. Guttaflow sealer, respectively. The contact angle was measured using First Ten Angstroms (FTA 200 dynamic contact angle analyzer. Results: The contact angle values for AH Plus sealer were significantly lower when compared to the other two sealer groups. Conclusion: The wettability of AH Plus sealer on the root surface dentin was found to be better than Gutta-Flow and ZnOE sealer.

  19. Flavonoids modify root growth and modulate expression of SHORT-ROOT and HD-ZIP III.

    Science.gov (United States)

    Franco, Danilo Miralha; Silva, Eder Marques; Saldanha, Luiz Leonardo; Adachi, Sérgio Akira; Schley, Thayssa Rabelo; Rodrigues, Tatiane Maria; Dokkedal, Anne Ligia; Nogueira, Fabio Tebaldi Silveira; Rolim de Almeida, Luiz Fernando

    2015-09-01

    Flavonoids are a class of distinct compounds produced by plant secondary metabolism that inhibit or promote plant development and have a relationship with auxin transport. We showed that, in terms of root development, Copaifera langsdorffii leaf extracts has an inhibitory effect on most flavonoid components compared with the application of exogenous flavonoids (glycosides and aglycones). These compounds alter the pattern of expression of the SHORT-ROOT and HD-ZIP III transcription factor gene family and cause morpho-physiological alterations in sorghum roots. In addition, to examine the flavonoid auxin interaction in stress, we correlated the responses with the effects of exogenous application of auxin and an auxin transport inhibitor. The results show that exogenous flavonoids inhibit primary root growth and increase the development of lateral roots. Exogenous flavonoids also change the pattern of expression of specific genes associated with root tissue differentiation. These findings indicate that flavonoid glycosides can influence the polar transport of auxin, leading to stress responses that depend on auxin.

  20. Phototropism and gravitropism in lateral roots of Arabidopsis.

    Science.gov (United States)

    Kiss, John Z; Miller, Kelley M; Ogden, Lisa A; Roth, Kelly K

    2002-01-01

    Gravitropism and, to a lesser extent, phototropism have been characterized in primary roots, but little is known about structural/functional aspects of these tropisms in lateral roots. Therefore, in this study, we report on tropistic responses in lateral roots of Arabidopsis thaliana. Lateral roots initially are plagiogravitropic, but when they reach a length of approximately 10 mm, these roots grow downward and exhibit positive orthogravitropism. Light and electron microscopic studies demonstrate a correlation between positive gravitropism and development of columella cells with large, sedimented amyloplasts in wild-type plants. Lateral roots display negative phototropism in response to white and blue light and positive phototropism in response to red light. As is the case with primary roots, the photoresponse is weak relative to the graviresponse, but phototropism is readily apparent in starchless mutant plants, which are impaired in gravitropism. To our knowledge, this is the first report of phototropism of lateral roots in any plant species.

  1. 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.

  2. COUNTING ROOTED NEAR-4-REGULAR EULERIAN MAPS ON SOME SURFACES

    Institute of Scientific and Technical Information of China (English)

    RenHan; LiuYanpei

    1999-01-01

    In this article the rooted planar near-4-regular Eulerian trails are enumerated and an explicit formula for such maps is presented. Further, the rooted near-4-regular Eulerian maps on the torus are counted in an exact way.

  3. Bessel functions for root systems via the trigonometric setting

    DEFF Research Database (Denmark)

    Ørsted, Bent; Said, S.B.

    2005-01-01

    In this paper, we study generalized Bessel functions related to root systems and give explicit formulas in several cases.......In this paper, we study generalized Bessel functions related to root systems and give explicit formulas in several cases....

  4. Role of calcium in gravity perception of plant roots

    Science.gov (United States)

    Evans, Michael L.

    1986-01-01

    Calcium ions may play a key role in linking graviperception by the root cap to the asymmetric growth which occurs in the elongation zone of gravistimulated roots. Application of calcium-chelating agents to the root cap inhibits gravitropic curvature without affecting growth. Asymmetric application of calcium to one side of the root cap induces curvature toward the calcium source, and gravistimulation induces polar movement of applied (Ca-45)(2+) across the root cap toward the lower side. The action of calcium may be linked to auxin movement in roots since: (1) auxin transport inhibitors interfere both with gravitropic curvature and graviinduced polar calcium movement and (2) asymmetric application of calcium enhances auxin movement across the elongation zone of gravistimulated roots. Indirect evidence indicates that the calcium-modulated regulator protein, calmodulin, may be involved in either the transport or action of calcium in the gravitropic response mechanism of roots.

  5. Regeneration of roots from callus reveals stability of the developmental program for determinate root growth in Sonoran Desert Cactaceae.

    Science.gov (United States)

    Shishkova, Svetlana; García-Mendoza, Edith; Castillo-Díaz, Vicente; Moreno, Norma E; Arellano, Jesús; Dubrovsky, Joseph G

    2007-05-01

    In some Sonoran Desert Cactaceae the primary root has a determinate root growth: the cells of the root apical meristem undergo only a few cell division cycles and then differentiate. The determinate growth of primary roots in Cactaceae was found in plants cultivated under various growth conditions, and could not be reverted by any treatment tested. The mechanisms involved in root meristem maintenance and determinate root growth in plants remain poorly understood. In this study, we have shown that roots regenerated from the callus of two Cactaceae species, Stenocereus gummosus and Ferocactus peninsulae, have a determinate growth pattern, similar to that of the primary root. To demonstrate this, a protocol for root regeneration from callus was established. The determinate growth pattern of roots regenerated from callus suggests that the program of root development is very stable in these species. These findings will permit future analysis of the role of certain Cactaceae genes in the determinate pattern of root growth via the regeneration of transgenic roots from transformed calli.

  6. Visualization of root water uptake: quantification of deuterated water transport in roots using neutron radiography and numerical modeling.

    Science.gov (United States)

    Zarebanadkouki, Mohsen; Kroener, Eva; Kaestner, Anders; Carminati, Andrea

    2014-10-01

    Our understanding of soil and plant water relations is limited by the lack of experimental methods to measure water fluxes in soil and plants. Here, we describe a new method to noninvasively quantify water fluxes in roots. To this end, neutron radiography was used to trace the transport of deuterated water (D2O) into roots. The results showed that (1) the radial transport of D2O from soil to the roots depended similarly on diffusive and convective transport and (2) the axial transport of D2O along the root xylem was largely dominated by convection. To quantify the convective fluxes from the radiographs, we introduced a convection-diffusion model to simulate the D2O transport in roots. The model takes into account different pathways of water across the root tissue, the endodermis as a layer with distinct transport properties, and the axial transport of D2O in the xylem. The diffusion coefficients of the root tissues were inversely estimated by simulating the experiments at night under the assumption that the convective fluxes were negligible. Inverse modeling of the experiment at day gave the profile of water fluxes into the roots. For a 24-d-old lupine (Lupinus albus) grown in a soil with uniform water content, root water uptake was higher in the proximal parts of lateral roots and decreased toward the distal parts. The method allows the quantification of the root properties and the regions of root water uptake along the root systems.

  7. Internal root resorption in the maxillary central incisor

    OpenAIRE

    2010-01-01

    Introduction: Internal root resorption is a chronic inflammatory process initiated within the pulp space with the loss of dentin. The clastic cells present in the pulp tissue trigger a progressive resorption phenomenon. Case report and conclusion: This paper reports a clinical case of an internal root resorption in the permanent central incisor, at the middle third of the root canal. Because it is asymptomatic,internal root resorption needs an early diagnosis in order to institute the endodon...

  8. Distribution of Primitive λ-Roots of Composite Moduli Ⅱ

    Institute of Scientific and Technical Information of China (English)

    Zhiyong ZHENG; Todd COCHRANE

    2006-01-01

    We improve estimates for the distribution of primitive λ-roots of a composite modulus q yielding an asymptotic formula for the number of primitive λ-roots in any interval Ⅰ of length |I| (>>) q1/2+∈. Similar results are obtained for the distribution of ordered pairs (x, x-1) with x a primitive λ-root, and for the number of primitive λ-roots satisfying inequalities such as |x -x-1| ≤ B.

  9. How to study deep roots-and why it matters.

    Science.gov (United States)

    Maeght, Jean-Luc; Rewald, Boris; Pierret, Alain

    2013-01-01

    The drivers underlying the development of deep root systems, whether genetic or environmental, are poorly understood but evidence has accumulated that deep rooting could be a more widespread and important trait among plants than commonly anticipated from their share of root biomass. Even though a distinct classification of "deep roots" is missing to date, deep roots provide important functions for individual plants such as nutrient and water uptake but can also shape plant communities by hydraulic lift (HL). Subterranean fauna and microbial communities are highly influenced by resources provided in the deep rhizosphere and deep roots can influence soil pedogenesis and carbon storage.Despite recent technological advances, the study of deep roots and their rhizosphere remains inherently time-consuming, technically demanding and costly, which explains why deep roots have yet to be given the attention they deserve. While state-of-the-art technologies are promising for laboratory studies involving relatively small soil volumes, they remain of limited use for the in situ observation of deep roots. Thus, basic techniques such as destructive sampling or observations at transparent interfaces with the soil (e.g., root windows) which have been known and used for decades to observe roots near the soil surface, must be adapted to the specific requirements of deep root observation. In this review, we successively address major physical, biogeochemical and ecological functions of deep roots to emphasize the significance of deep roots and to illustrate the yet limited knowledge. In the second part we describe the main methodological options to observe and measure deep roots, providing researchers interested in the field of deep root/rhizosphere studies with a comprehensive overview. Addressed methodologies are: excavations, trenches and soil coring approaches, minirhizotrons (MR), access shafts, caves and mines, and indirect approaches such as tracer-based techniques.

  10. 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...

  11. Distribution of the residual roots in principal components analysis.

    Directory of Open Access Journals (Sweden)

    A. M. Kshirsagar

    1964-10-01

    Full Text Available The latent of distribution of latent roots of the covariance martix of normal variables, when a hypothetical linear function of the variables is eliminated, is derived in this paper. The relation between original roots and the residual roots- after elimination of, is also derived by an analytical method. An exact test for the goodness of fit of a single nonisotropic hypothetical principal components, using the residual roots, is then obtained.

  12. Artificial Root Exudate System (ARES): a field approach to simulate tree root exudation in soils

    Science.gov (United States)

    Lopez-Sangil, Luis; Estradera-Gumbau, Eduard; George, Charles; Sayer, Emma

    2016-04-01

    The exudation of labile solutes by fine roots represents an important strategy for plants to promote soil nutrient availability in terrestrial ecosystems. Compounds exuded by roots (mainly sugars, carboxylic and amino acids) provide energy to soil microbes, thus priming the mineralization of soil organic matter (SOM) and the consequent release of inorganic nutrients into the rhizosphere. Studies in several forest ecosystems suggest that tree root exudates represent 1 to 10% of the total photoassimilated C, with exudation rates increasing markedly under elevated CO2 scenarios. Despite their importance in ecosystem functioning, we know little about how tree root exudation affect soil carbon dynamics in situ. This is mainly because there has been no viable method to experimentally control inputs of root exudates at field scale. Here, I present a method to apply artificial root exudates below the soil surface in small field plots. The artificial root exudate system (ARES) consists of a water container with a mixture of labile carbon solutes (mimicking tree root exudate rates and composition), which feeds a system of drip-tips covering an area of 1 m2. The tips are evenly distributed every 20 cm and inserted 4-cm into the soil with minimal disturbance. The system is regulated by a mechanical timer, such that artificial root exudate solution can be applied at frequent, regular daily intervals. We tested ARES from April to September 2015 (growing season) within a leaf-litter manipulation experiment ongoing in temperate deciduous woodland in the UK. Soil respiration was measured monthly, and soil samples were taken at the end of the growing season for PLFA, enzymatic activity and nutrient analyses. First results show a very rapid mineralization of the root exudate compounds and, interestingly, long-term increases in SOM respiration, with negligible effects on soil moisture levels. Large positive priming effects (2.5-fold increase in soil respiration during the growing

  13. Root Ecological Niche Index and Root Distribution Characteristics of Artificial Phytocommunities in Rehabilitated Fields

    Institute of Scientific and Technical Information of China (English)

    Hu Jianzhong; Zhen Jiali; Shen Jingyu

    2006-01-01

    In the implementation phase of the Conversion of Cropland to Forest and Grassland (CCFG) project in China,it is important,from a scientific point of view,to recognize phytocommunities' characteristics,species compatibility,and ecological function.The ecological niche that roots occupy,their abundance and distribution,and the factors that affect them must be acknowledged.Following the methodology of community ecology,the total root mass of a phytocommunity is measured as cubic volume.Root biomass,length,and the number of roots in every diameter class,for each soil layer and for each plant species,are regarded as observation variables.In the first instance therefore,a new method to calculate the root ecological niche index (REND is proposed,embracing the entire phytocommunity of plantations.Using the new method,the roots of pbytocommunities in Datong County,Qinghai Province (one of the counties selected for the national CCFG experiment),are dealt with in this paper.The results show that most of the vertical distributions of plant roots belong to the type wherein the roots are concentrated in the topsoil layer (0-20 cm),far more than those in the lower soil layers.The RENI of pbytocommunities is higher than that of pure stands or monocultures.The distribution of RENI by root diameter can be divided into four types:J-type,inverse J-type,recumbent S-type,and U-type.RENI is positively correlated with the wet biomass of aboveground level stems,branches,and plant leaves,and with the species richness of phytocommunities.Although the RENIs of plantations in rehabilitated fields are a little lower than those of natural forests,they are higher than those of cultivated crops.The RENIs of three community types (Picea crassifolia+Hippophae rhamnoides ssp.sinensis,H.rhamnoides ssp.sinensis,and P.crassifolia) in rehabilitated fields benefit greatly from the restoration project.The implementation of the CCFG project is important for the increase in RENI and the multiple functions of

  14. A novel root based Arabic stemmer

    Directory of Open Access Journals (Sweden)

    Mohammed N. Al-Kabi

    2015-04-01

    Full Text Available Stemming algorithms are used in information retrieval systems, indexers, text mining, text classifiers etc., to ex