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Sample records for altering root system

  1. Responses of grapevine rootstocks to drought through altered root system architecture and root transcriptomic regulations.

    Science.gov (United States)

    Yıldırım, Kubilay; Yağcı, Adem; Sucu, Seda; Tunç, Sümeyye

    2018-06-01

    Roots are the major interface between the plant and various stress factors in the soil environment. Alteration of root system architecture (RSA) (root length, spread, number and length of lateral roots) in response to environmental changes is known to be an important strategy for plant adaptation and productivity. In light of ongoing climate changes and global warming predictions, the breeding of drought-tolerant grapevine cultivars is becoming a crucial factor for developing a sustainable viticulture. Root-trait modeling of grapevine rootstock for drought stress scenarios, together with high-throughput phenotyping and genotyping techniques, may provide a valuable background for breeding studies in viticulture. Here, tree grafted grapevine rootstocks (110R, 5BB and 41B) having differential RSA regulations and drought tolerance were investigated to define their drought dependent root characteristics. Root area, root length, ramification and number of root tips reduced less in 110R grafted grapevines compared to 5BB and 41B grafted ones during drought treatment. Root relative water content as well as total carbohydrate and nitrogen content were found to be much higher in the roots of 110R than it was in the roots of other rootstocks under drought. Microarray-based root transcriptome profiling was also conducted on the roots of these rootstocks to identify their gene regulation network behind drought-dependent RSA alterations. Transcriptome analysis revealed totally 2795, 1196 and 1612 differentially expressed transcripts at the severe drought for the roots of 110R, 5BB and 41B, respectively. According to this transcriptomic data, effective root elongation and enlargement performance of 110R were suggested to depend on three transcriptomic regulations. First one is the drought-dependent induction in sugar and protein transporters genes (SWEET and NRT1/PTR) in the roots of 110R to facilitate carbohydrate and nitrogen accumulation. In the roots of the same rootstock

  2. Low Light Availability Alters Root Exudation and Reduces Putative Beneficial Microorganisms in Seagrass Roots

    Directory of Open Access Journals (Sweden)

    Belinda C. Martin

    2018-01-01

    Full Text Available Seagrass roots host a diverse microbiome that is critical for plant growth and health. Composition of microbial communities can be regulated in part by root exudates, but the specifics of these interactions in seagrass rhizospheres are still largely unknown. As light availability controls primary productivity, reduced light may impact root exudation and consequently the composition of the root microbiome. Hence, we analyzed the influence of light availability on root exudation and community structure of the root microbiome of three co-occurring seagrass species, Halophila ovalis, Halodule uninervis and Cymodocea serrulata. Plants were grown under four light treatments in mesocosms for 2 weeks; control (100% surface irradiance (SI, medium (40% SI, low (20% SI and fluctuating light (10 days 20% and 4 days 100%. 16S rDNA amplicon sequencing revealed that microbial diversity, composition and predicted function were strongly influenced by the presence of seagrass roots, such that root microbiomes were unique to each seagrass species. Reduced light availability altered seagrass root exudation, as characterized using fluorescence spectroscopy, and altered the composition of seagrass root microbiomes with a reduction in abundance of potentially beneficial microorganisms. Overall, this study highlights the potential for above-ground light reduction to invoke a cascade of changes from alterations in root exudation to a reduction in putative beneficial microorganisms and, ultimately, confirms the importance of the seagrass root environment – a critical, but often overlooked space.

  3. Control of root system architecture by DEEPER ROOTING 1 increases rice yield under drought conditions.

    Science.gov (United States)

    Uga, Yusaku; Sugimoto, Kazuhiko; Ogawa, Satoshi; Rane, Jagadish; Ishitani, Manabu; Hara, Naho; Kitomi, Yuka; Inukai, Yoshiaki; Ono, Kazuko; Kanno, Noriko; Inoue, Haruhiko; Takehisa, Hinako; Motoyama, Ritsuko; Nagamura, Yoshiaki; Wu, Jianzhong; Matsumoto, Takashi; Takai, Toshiyuki; Okuno, Kazutoshi; Yano, Masahiro

    2013-09-01

    The genetic improvement of drought resistance is essential for stable and adequate crop production in drought-prone areas. Here we demonstrate that alteration of root system architecture improves drought avoidance through the cloning and characterization of DEEPER ROOTING 1 (DRO1), a rice quantitative trait locus controlling root growth angle. DRO1 is negatively regulated by auxin and is involved in cell elongation in the root tip that causes asymmetric root growth and downward bending of the root in response to gravity. Higher expression of DRO1 increases the root growth angle, whereby roots grow in a more downward direction. Introducing DRO1 into a shallow-rooting rice cultivar by backcrossing enabled the resulting line to avoid drought by increasing deep rooting, which maintained high yield performance under drought conditions relative to the recipient cultivar. Our experiments suggest that control of root system architecture will contribute to drought avoidance in crops.

  4. Non-canonical WOX11-mediated root branching contributes to plasticity in Arabidopsis root system architecture.

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    Sheng, Lihong; Hu, Xiaomei; Du, Yujuan; Zhang, Guifang; Huang, Hai; Scheres, Ben; Xu, Lin

    2017-09-01

    Lateral roots (LRs), which originate from the growing root, and adventitious roots (ARs), which are formed from non-root organs, are the main contributors to the post-embryonic root system in Arabidopsis However, our knowledge of how formation of the root system is altered in response to diverse inductive cues is limited. Here, we show that WOX11 contributes to root system plasticity. When seedlings are grown vertically on medium, WOX11 is not expressed in LR founder cells. During AR initiation, WOX11 is expressed in AR founder cells and activates LBD16 LBD16 also functions in LR formation and is activated in that context by ARF7 / 19 and not by WOX11 This indicates that divergent initial processes that lead to ARs and LRs may converge on a similar mechanism for primordium development. Furthermore, we demonstrated that when plants are grown in soil or upon wounding on medium, the primary root is able to produce both WOX11 -mediated and non- WOX11 -mediated roots. The discovery of WOX11 -mediated root-derived roots reveals a previously uncharacterized pathway that confers plasticity during the generation of root system architecture in response to different inductive cues. © 2017. Published by The Company of Biologists Ltd.

  5. The Influence of Plant Root Systems on Subsurface Flow: Implications for Slope Stability

    Science.gov (United States)

    Although research has explained how plant roots mechanically stabilize soils, in this article we explore how root systems create networks of preferential flow and thus influence water pressures in soils to trigger landslides. Root systems may alter subsurface flow: Hydrological m...

  6. Automated Root Tracking with "Root System Analyzer"

    Science.gov (United States)

    Schnepf, Andrea; Jin, Meina; Ockert, Charlotte; Bol, Roland; Leitner, Daniel

    2015-04-01

    Crucial factors for plant development are water and nutrient availability in soils. Thus, root architecture is a main aspect of plant productivity and needs to be accurately considered when describing root processes. Images of root architecture contain a huge amount of information, and image analysis helps to recover parameters describing certain root architectural and morphological traits. The majority of imaging systems for root systems are designed for two-dimensional images, such as RootReader2, GiA Roots, SmartRoot, EZ-Rhizo, and Growscreen, but most of them are semi-automated and involve mouse-clicks in each root by the user. "Root System Analyzer" is a new, fully automated approach for recovering root architectural parameters from two-dimensional images of root systems. Individual roots can still be corrected manually in a user interface if required. The algorithm starts with a sequence of segmented two-dimensional images showing the dynamic development of a root system. For each image, morphological operators are used for skeletonization. Based on this, a graph representation of the root system is created. A dynamic root architecture model helps to determine which edges of the graph belong to an individual root. The algorithm elongates each root at the root tip and simulates growth confined within the already existing graph representation. The increment of root elongation is calculated assuming constant growth. For each root, the algorithm finds all possible paths and elongates the root in the direction of the optimal path. In this way, each edge of the graph is assigned to one or more coherent roots. Image sequences of root systems are handled in such a way that the previous image is used as a starting point for the current image. The algorithm is implemented in a set of Matlab m-files. Output of Root System Analyzer is a data structure that includes for each root an identification number, the branching order, the time of emergence, the parent

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

    Directory of Open Access Journals (Sweden)

    Swarnalee Dutta

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

  8. Isolation and characterization of altered root growth behavior and ...

    African Journals Online (AJOL)

    Ezedom Theresa

    2013-10-02

    Oct 2, 2013 ... contrasting root growth behavior and salinity tolerance in rice will help us to identify key genes controlling ..... In order to screen plants showing altered response ... were found to remain green even after 15 days of salinity.

  9. Graviresponsiveness of surgically altered primary roots of Zea mays

    Science.gov (United States)

    Maimon, E.; Moore, R.

    1991-01-01

    We examined the gravitropic responses of surgically altered primary roots of Zea mays to determine the route by which gravitropic inhibitors move from the root tip to the elongating zone. Horizontally oriented roots, from which a 1-mm-wide girdle of epidermis plus 2-10 layers of cortex were removed from the apex of the elongating zone, curve downward. However, curvature occurred only apical to the girdle. Filling the girdle with mucilage-like material transmits curvature beyond the girdle. Vertically oriented roots with a half-girdle' (i.e. the epidermis and 2-10 layers of the cortex removed from half of the circumference of the apex of the elongating zone) curve away from the girdle. Inserting the half-girdle at the base of the elongating zone induces curvature towards the girdle. Filling the half-circumference girdles with mucilage-like material reduced curvature significantly. Stripping the epidermis and outer 2-5 layers of cortex from the terminal 1.5 cm of one side of a primary root induces curvature towards the cut, irrespective of the root's orientation to gravity. This effect is not due to desiccation since treated roots submerged in water also curved towards their cut surface. Coating a root's cut surface with a mucilage-like substance minimizes curvature. These results suggest that the outer cell-layers of the root, especially the epidermis, play an important role in root gravicurvature, and the gravitropic signals emanating from the root tip can move apoplastically through mucilage.

  10. X-ray computed tomography uncovers root-root interactions: quantifying spatial relationships between interacting root systems in three dimensions.

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    Paya, Alexander M; Silverberg, Jesse L; Padgett, Jennifer; Bauerle, Taryn L

    2015-01-01

    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 2 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.

  11. Does altered aortic flow in marfan syndrome relate to aortic root dilatation?

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    Wang, Hung-Hsuan; Chiu, Hsin-Hui; Tseng, Wen-Yih Isaac; Peng, Hsu-Hsia

    2016-08-01

    To examine possible hemodynamic alterations in adolescent to adult Marfan syndrome (MFS) patients with aortic root dilatation. Four-dimensional flow MRI was performed in 20 MFS patients and 12 age-matched normal subjects with a 3T system. The cross-sectional areas of 10 planes along the aorta were segmented for calculating the axial and circumferential wall shear stress (WSSaxial , WSScirc ), oscillatory shear index (OSIaxial , OSIcirc ), and the nonroundness (NR), presenting the asymmetry of segmental WSS. Pearson's correlation analysis was performed to present the correlations between the quantified indices and the body surface area (BSA), aortic root diameter (ARD), and Z score of the ARD. P < 0.05 indicated statistical significance. Patients exhibited lower WSSaxial in the aortic root and the WSScirc in the arch (P < 0.05-0.001). MFS patients exhibited higher OSIaxial and OSIcirc in the sinotubular junction and arch, but lower OSIcirc in the descending aorta (all P < 0.05). The NR values were lower in patients (P < 0.05). The WSSaxial or WSScirc exhibited moderate to strong correlations with BSA, ARD, or Z score (R(2)  = 0.50-0.72) in MFS patients. The significant differences in the quantified indices, which were associated with BSA, ARD, or Z score, in MFS were opposite to previous reports for younger MFS patients, indicating that altered flows in MFS patients may depend on the disease progress. The possible time dependency of hemodynamic alterations in MFS patients strongly suggests that longitudinal follow-up of 4D Flow is needed to comprehend disease progress. J. Magn. Reson. Imaging 2016;44:500-508. © 2016 Wiley Periodicals, Inc.

  12. computer-aided root aided root aided root aided root-locus

    African Journals Online (AJOL)

    User

    m, stability, transient response, root-locus, iteration he means by which any a machine, mechanism or d or altered in accordance. Introduction of feedback has the advantages of f system performance to in system parameters, ponse and minimizing the ignals. However, feedback of components, increases ain and introduces ...

  13. Oak protein profile alterations upon root colonization by an ectomycorrhizal fungus

    DEFF Research Database (Denmark)

    Sebastiana, Mónica; Martins, Joana; Figueiredo, Andreia

    2017-01-01

    in the roots. Consistent with the results of the biochemical analysis, the proteome analysis of the mycorrhizal roots suggests a decreasing utilization of sucrose for the metabolic activity of mycorrhizal roots which is consistent with an increased allocation of carbohydrates from the plant to the fungus...... to ectomycorrhizae formation using a proteomics approach complemented by biochemical analysis of carbohydrate levels. Comparative proteome analysis between mycorrhizal and nonmycorrhizal cork oak plants revealed no differences at the foliar level. However, the protein profile of 34 unique oak proteins was altered...... in order to sustain the symbiosis. In addition, a promotion of protein unfolding mechanisms, attenuation of defense reactions, increased nutrient mobilization from the plant-fungus interface (N and P), as well as cytoskeleton rearrangements and induction of plant cell wall loosening for fungal root...

  14. Comparative study of 6 rotary nickel-titanium systems and hand instrumentation for root canal preparation in severely curved root canals of extracted teeth.

    Science.gov (United States)

    Celik, Davut; Taşdemir, Tamer; Er, Kürşat

    2013-02-01

    Some improvements have been developed with new generations of nickel-titanium (NiTi) rotary instruments that led to their successful and extensive application in clinical practice. The purpose of this in vitro study was to compare the root canal preparations performed by using GT Series X and Twisted File systems produced by innovative manufacturing process with Revo-S, RaCe, Mtwo, and ProTaper Universal systems manufactured directly from conventional nitinol and with stainless steel K-Flexofile instruments. The mesiobuccal root canals of 140 maxillary first permanent molars that had between 30°-40° curvature angle and 4- to 9-mm curvature radius of the root canal were used. After root canal preparations made by using GT Series X, Twisted File, Revo-S, RaCe, Mtwo, and ProTaper Universal NiTi rotary systems and stainless steel K-Flexofile instruments, transportation occurred in the root canal, and alteration of working length (WL) was assessed by using a modified double-digital radiographic technique. The data were compared by the post hoc Tukey honestly significant difference test. NiTi rotary systems caused less canal transportation and alteration of WL than K-Flexofile instruments (P .05) except 2.5 mm from the WL. At this level ProTaper Universal system caused significant canal transportation (P ProTaper Universal rotary systems manufactured by traditional methods. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  15. Evaluation of the anatomical alterations of lower molars mesial root?s apical third

    OpenAIRE

    FRÖNER Izabel Cristina; IMPERADOR Cristina Aparecida; SOUZA Luiz Gustavo de

    1999-01-01

    The anatomical apex of the mesial root of the lower molars presents a morphological complexity related to the number and shape of the root canals as well as of the apical foramen and isthmus presence. The knowledge of the complexity of the endodontic system of the molar root area is essencial to select more carefully the best instrumentation and obturation technique, to obtain a more successful endodontic therapy.

  16. Evaluation of the anatomical alterations of lower molars mesial root?s apical third

    Directory of Open Access Journals (Sweden)

    FRÖNER Izabel Cristina

    1999-01-01

    Full Text Available The anatomical apex of the mesial root of the lower molars presents a morphological complexity related to the number and shape of the root canals as well as of the apical foramen and isthmus presence. The knowledge of the complexity of the endodontic system of the molar root area is essencial to select more carefully the best instrumentation and obturation technique, to obtain a more successful endodontic therapy.

  17. Canopy sink-source partitioning influences root/soil respiration in apple

    Science.gov (United States)

    The root system of plants derives all its energy from photosynthate translocated from the canopy to the root system. Canopy manipulations that alter either the rate of canopy photosynthesis or the translocation of photosynthate are expected to alter dry matter partitioning to the root system. Fiel...

  18. The effect of altered dosage of a mutant allele of Teosinte branched 1 (tb1-ref) on the root system of modern maize.

    Science.gov (United States)

    Gaudin, Amelie C M; McClymont, Sarah A; Soliman, Sameh S M; Raizada, Manish N

    2014-02-14

    There was ancient human selection on the wild progenitor of modern maize, Balsas teosinte, for decreased shoot branching (tillering), in order to allow more nutrients to be diverted to grain. Mechanistically, the decline in shoot tillering has been associated with selection for increased expression of the major domestication gene Teosinte Branched 1 (Tb1) in shoot primordia. Therefore, TB1 has been defined as a repressor of shoot branching. It is known that plants respond to changes in shoot size by compensatory changes in root growth and architecture. However, it has not been reported whether altered TB1 expression affects any plant traits below ground. Previously, changes in dosage of a well-studied mutant allele of Tb1 in modern maize, called tb1-ref, from one to two copies, was shown to increase tillering. As a result, plants with two copies of the tb1-ref allele have a larger shoot biomass than heterozygotes. Here we used aeroponics to phenotype the effects of tb1-ref copy number on maize roots at macro-, meso- and micro scales of development. An increase in the tb1-ref copy number from one to two copies resulted in: (1) an increase in crown root number due to the cumulative initiation of crown roots from successive tillers; (2) higher density of first and second order lateral roots; and (3) reduced average lateral root length. The resulting increase in root system biomass in homozygous tb1-ref mutants balanced the increase in shoot biomass caused by enhanced tillering. These changes caused homozygous tb1-ref mutants of modern maize to more closely resemble its ancestor Balsas teosinte below ground. We conclude that a decrease in TB1 function in maize results in a larger root system, due to an increase in the number of crown roots and lateral roots. Given that decreased TB1 expression results in a more highly branched and larger shoot, the impact of TB1 below ground may be direct or indirect. We discuss the potential implications of these findings for whole

  19. An auxin transport independent pathway is involved in phosphate stress-induced root architectural alterations in Arabidopsis. Identification of BIG as a mediator of auxin in pericycle cell activation.

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    López-Bucio, José; Hernández-Abreu, Esmeralda; Sánchez-Calderón, Lenin; Pérez-Torres, Anahí; Rampey, Rebekah A; Bartel, Bonnie; Herrera-Estrella, Luis

    2005-02-01

    Arabidopsis (Arabidopsis thaliana) plants display a number of root developmental responses to low phosphate availability, including primary root growth inhibition, greater formation of lateral roots, and increased root hair elongation. To gain insight into the regulatory mechanisms by which phosphorus (P) availability alters postembryonic root development, we performed a mutant screen to identify genetic determinants involved in the response to P deprivation. Three low phosphate-resistant root lines (lpr1-1 to lpr1-3) were isolated because of their reduced lateral root formation in low P conditions. Genetic and molecular analyses revealed that all lpr1 mutants were allelic to BIG, which is required for normal auxin transport in Arabidopsis. Detailed characterization of lateral root primordia (LRP) development in wild-type and lpr1 mutants revealed that BIG is required for pericycle cell activation to form LRP in both high (1 mm) and low (1 microm) P conditions, but not for the low P-induced alterations in primary root growth, lateral root emergence, and root hair elongation. Exogenously supplied auxin restored normal lateral root formation in lpr1 mutants in the two P treatments. Treatment of wild-type Arabidopsis seedlings with brefeldin A, a fungal metabolite that blocks auxin transport, phenocopies the root developmental alterations observed in lpr1 mutants in both high and low P conditions, suggesting that BIG participates in vesicular targeting of auxin transporters. Taken together, our results show that auxin transport and BIG function have fundamental roles in pericycle cell activation to form LRP and promote root hair elongation. The mechanism that activates root system architectural alterations in response to P deprivation, however, seems to be independent of auxin transport and BIG.

  20. Can we manipulate root system architecture to control soil erosion?

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    Ola, A.; Dodd, I. C.; Quinton, J. N.

    2015-09-01

    Soil erosion is a major threat to soil functioning. The use of vegetation to control erosion has long been a topic for research. Much of this research has focused on the above-ground properties of plants, demonstrating the important role that canopy structure and cover plays in the reduction of water erosion processes. Less attention has been paid to plant roots. Plant roots are a crucial yet under-researched factor for reducing water erosion through their ability to alter soil properties, such as aggregate stability, hydraulic function and shear strength. However, there have been few attempts to specifically manipulate plant root system properties to reduce soil erosion. Therefore, this review aims to explore the effects that plant roots have on soil erosion and hydrological processes, and how plant root architecture might be manipulated to enhance its erosion control properties. We demonstrate the importance of root system architecture for the control of soil erosion. We also show that some plant species respond to nutrient-enriched patches by increasing lateral root proliferation. The erosional response to root proliferation will depend upon its location: at the soil surface dense mats of roots may reduce soil erodibility but block soil pores thereby limiting infiltration, enhancing runoff. Additionally, in nutrient-deprived regions, root hair development may be stimulated and larger amounts of root exudates released, thereby improving aggregate stability and decreasing erodibility. Utilizing nutrient placement at specific depths may represent a potentially new, easily implemented, management strategy on nutrient-poor agricultural land or constructed slopes to control erosion, and further research in this area is needed.

  1. A micro-computed tomographic evaluation of dentinal microcrack alterations during root canal preparation using single-file Ni-Ti systems.

    Science.gov (United States)

    Li, Mei-Lin; Liao, Wei-Li; Cai, Hua-Xiong

    2018-01-01

    The aim of the present study was to evaluate the length of dentinal microcracks observed prior to and following root canal preparation with different single-file nickel-titanium (Ni-Ti) systems using micro-computed tomography (micro-CT) analysis. A total of 80 mesial roots of mandibular first molars presenting with type II Vertucci canal configurations were scanned at an isotropic resolution of 7.4 µm. The samples were randomly assigned into four groups (n=20 per group) according to the system used for root canal preparation, including the WaveOne (WO), OneShape (OS), Reciproc (RE) and control groups. A second micro-CT scan was conducted after the root canals were prepared with size 25 instruments. Pre- and postoperative cross-section images of the roots (n=237,760) were then screened to identify the lengths of the microcracks. The results indicated that the microcrack lengths were notably increased following root canal preparation (Pfiles. Among the single-file Ni-Ti systems, WO and RE were not observed to cause notable microcracks, while the OS system resulted in evident microcracks.

  2. PhotosynthateRegulation of the Root System Architecture Mediated bythe Heterotrimeric G Protein Complex in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Yashwanti Mudgil

    2016-08-01

    Full Text Available Assimilate partitioning to the root system is a desirable developmental trait to control but little is known of the signaling pathway underlying partitioning. A null mutation in the gene encoding the Gβ subunit of the heterotrimeric G protein complex, a nexus for a variety of signaling pathways, confers altered sugar partitioning in roots. While fixed carbon rapidly reached the roots of wild type and agb1-2 mutant seedlings, agb1 roots had more of this fixed carbon in the form of glucose, fructose, and sucrose which manifested as a higher lateral root density. Upon glucose treatment, the agb1-2 mutant had abnormal gene expression in the root tip validated by transcriptome analysis. In addition, PIN2 membrane localization and level was altered in the agb1-2 mutant. The heterotrimeric G protein complex integrates photosynthesis-derived sugar signaling incorporating both membrane-and transcriptional-based mechanisms. The time constants for these signaling mechanisms are in the same range as photosynthate delivery to the root, raising the possibility that root cells are able to use changes in carbon fixation in real time to adjust growth behavior.

  3. Photosynthate Regulation of the Root System Architecture Mediated by the Heterotrimeric G Protein Complex in Arabidopsis.

    Science.gov (United States)

    Mudgil, Yashwanti; Karve, Abhijit; Teixeira, Paulo J P L; Jiang, Kun; Tunc-Ozdemir, Meral; Jones, Alan M

    2016-01-01

    Assimilate partitioning to the root system is a desirable developmental trait to control but little is known of the signaling pathway underlying partitioning. A null mutation in the gene encoding the Gβ subunit of the heterotrimeric G protein complex, a nexus for a variety of signaling pathways, confers altered sugar partitioning in roots. While fixed carbon rapidly reached the roots of wild type and agb1-2 mutant seedlings, agb1 roots had more of this fixed carbon in the form of glucose, fructose, and sucrose which manifested as a higher lateral root density. Upon glucose treatment, the agb1-2 mutant had abnormal gene expression in the root tip validated by transcriptome analysis. In addition, PIN2 membrane localization was altered in the agb1-2 mutant. The heterotrimeric G protein complex integrates photosynthesis-derived sugar signaling incorporating both membrane-and transcriptional-based mechanisms. The time constants for these signaling mechanisms are in the same range as photosynthate delivery to the root, raising the possibility that root cells are able to use changes in carbon fixation in real time to adjust growth behavior.

  4. An aeroponic culture system for the study of root herbivory on Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Vaughan Martha M

    2011-03-01

    Full Text Available Abstract Background Plant defense against herbivory has been studied primarily in aerial tissues. However, complex defense mechanisms have evolved in all parts of the plant to combat herbivore attack and these mechanisms are likely to differ in the aerial and subterranean environment. Research investigating defense responses belowground has been hindered by experimental difficulties associated with the accessibility and quality of root tissue and the lack of bioassays using model plants with altered defense profiles. Results We have developed an aeroponic culture system based on a calcined clay substrate that allows insect herbivores to feed on plant roots while providing easy recovery of the root tissue. The culture method was validated by a root-herbivore system developed for Arabidopsis thaliana and the herbivore Bradysia spp. (fungus gnat. Arabidopsis root mass obtained from aeroponically grown plants was comparable to that from other culture systems, and the plants were morphologically normal. Bradysia larvae caused considerable root damage resulting in reduced root biomass and water absorption. After feeding on the aeroponically grown root tissue, the larvae pupated and emerged as adults. Root damage of mature plants cultivated in aeroponic substrate was compared to that of Arabidopsis seedlings grown in potting mix. Seedlings were notably more susceptible to Bradysia feeding than mature plants and showed decreased overall growth and survival rates. Conclusions A root-herbivore system consisting of Arabidopsis thaliana and larvae of the opportunistic herbivore Bradysia spp. has been established that mimics herbivory in the rhizosphere. Bradysia infestation of Arabidopsis grown in this culture system significantly affects plant performance. The culture method will allow simple profiling and in vivo functional analysis of root defenses such as chemical defense metabolites that are released in response to belowground insect attack.

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

    Science.gov (United States)

    Pedrotti, Lorenzo; Mueller, Martin J; Waller, Frank

    2013-01-01

    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.

  6. GLO-Roots: an imaging platform enabling multidimensional characterization of soil-grown root systems

    Science.gov (United States)

    Rellán-Álvarez, Rubén; Lobet, Guillaume; Lindner, Heike; Pradier, Pierre-Luc; Sebastian, Jose; Yee, Muh-Ching; Geng, Yu; Trontin, Charlotte; LaRue, Therese; Schrager-Lavelle, Amanda; Haney, Cara H; Nieu, Rita; Maloof, Julin; Vogel, John P; Dinneny, José R

    2015-01-01

    Root systems develop different root types that individually sense cues from their local environment and integrate this information with systemic signals. This complex multi-dimensional amalgam of inputs enables continuous adjustment of root growth rates, direction, and metabolic activity that define a dynamic physical network. Current methods for analyzing root biology balance physiological relevance with imaging capability. To bridge this divide, we developed an integrated-imaging system called Growth and Luminescence Observatory for Roots (GLO-Roots) that uses luminescence-based reporters to enable studies of root architecture and gene expression patterns in soil-grown, light-shielded roots. We have developed image analysis algorithms that allow the spatial integration of soil properties, gene expression, and root system architecture traits. We propose GLO-Roots as a system that has great utility in presenting environmental stimuli to roots in ways that evoke natural adaptive responses and in providing tools for studying the multi-dimensional nature of such processes. DOI: http://dx.doi.org/10.7554/eLife.07597.001 PMID:26287479

  7. Root systems of chaparral shrubs.

    Science.gov (United States)

    Kummerow, Jochen; Krause, David; Jow, William

    1977-06-01

    Root systems of chaparral shrubs were excavated from a 70 m 2 plot of a mixed chaparral stand located on a north-facing slope in San Diego County (32°54' N; 900 m above sea level). The main shrub species present were Adenostoma fasciculatum, Arctostaphylos pungens, Ceanothus greggii, Erigonum fasciculatum, and Haplopappus pinifolius. Shrubs were wired into their positions, and the soil was washed out beneath them down to a depth of approximately 60 cm, where impenetrable granite impeded further washing and root growth was severely restricted. Spacing and interweaving of root systems were recorded by an in-scale drawing. The roots were harvested in accordance to their depths, separated into diameter size classes for each species, and their dry weights measured. Roots of shrubs were largely confined to the upper soil levels. The roots of Eriogonum fasciculatum were concentrated in the upper soil layer. Roots of Adenostoma fasciculatum tended to be more superficial than those from Ceanothus greggii. It is hypothesized that the shallow soil at the excavation site impeded a clear depth zonation of the different root systems. The average dry weight root:shoot ratio was 0.6, ranging for the individual shrubs from 0.8 to 0.4. The root area always exceeded the shoot area, with the corresponding ratios ranging from 6 for Arctostaphylos pungens to 40 for Haplopappus pinifolius. The fine root density of 64 g dry weight per m 2 under the canopy was significantly higher than in the unshaded area. However, the corresponding value of 45 g dry weight per m 2 for the open ground is still high enough to make the establishment of other shrubs difficult.

  8. Characterization of Root and Shoot Traits in Wheat Cultivars with Putative Differences in Root System Size

    Directory of Open Access Journals (Sweden)

    Victoria Figueroa-Bustos

    2018-07-01

    Full Text Available Root system size is a key trait for improving water and nitrogen uptake efficiency in wheat (Triticum aestivum L.. This study aimed (i to characterize the root system and shoot traits of five wheat cultivars with apparent differences in root system size; (ii to evaluate whether the apparent differences in root system size observed at early vegetative stages in a previous semi-hydroponic phenotyping experiment are reflected at later phenological stages in plants grown in soil using large rhizoboxes. The five wheat cultivars were grown in a glasshouse in rhizoboxes filled to 1.0 m with field soil. Phenology and shoot traits were measured and root growth and proliferation were mapped to quantify root length density (RLD, root length per plant, root biomass and specific root length (SRL. Wheat cultivars with large root systems had greater root length, more root biomass and thicker roots, particularly in the top 40 cm, than those with small root systems. Cultivars that reached anthesis later had larger root system sizes than those that reached anthesis earlier. Later anthesis allowed more time for root growth and proliferation. Cultivars with large root systems had 25% more leaf area and biomass than those with small root systems, which presumably reflects high canopy photosynthesis to supply the demand for carbon assimilates to roots. Wheat cultivars with contrasting root system sizes at the onset of tillering (Z2.1 in a semi-hydroponic phenotyping system maintained their size ranking at booting (Z4.5 when grown in soil. Phenology, particularly time to anthesis, was associated with root system size.

  9. Introduction to the ROOT System

    CERN Multimedia

    CERN. Geneva

    2008-01-01

    Introduction to the ROOT data handling system. ROOT is used in some for or another by all LHC experiments and will be used by all for final data analysis. The introduction gives an overview of the system. Prerequisite knowledge: C++

  10. Sorghum root-system classification in contrasting P environments reveals three main rooting types and root-architecture-related marker-trait associations.

    Science.gov (United States)

    Parra-Londono, Sebastian; Kavka, Mareike; Samans, Birgit; Snowdon, Rod; Wieckhorst, Silke; Uptmoor, Ralf

    2018-02-12

    Roots facilitate acquisition of macro- and micronutrients, which are crucial for plant productivity and anchorage in the soil. Phosphorus (P) is rapidly immobilized in the soil and hardly available for plants. Adaptation to P scarcity relies on changes in root morphology towards rooting systems well suited for topsoil foraging. Root-system architecture (RSA) defines the spatial organization of the network comprising primary, lateral and stem-derived roots and is important for adaptation to stress conditions. RSA phenotyping is a challenging task and essential for understanding root development. In this study, 19 traits describing RSA were analysed in a diversity panel comprising 194 sorghum genotypes, fingerprinted with a 90-k single-nucleotide polymorphism (SNP) array and grown under low and high P availability. Multivariate analysis was conducted and revealed three different RSA types: (1) a small root system; (2) a compact and bushy rooting type; and (3) an exploratory root system, which might benefit plant growth and development if water, nitrogen (N) or P availability is limited. While several genotypes displayed similar rooting types in different environments, others responded to P scarcity positively by developing more exploratory root systems, or negatively with root growth suppression. Genome-wide association studies revealed significant quantitative trait loci (P root-system development on chromosomes SBI-02 and SBI-03. Sorghum genotypes with a compact, bushy and shallow root system provide potential adaptation to P scarcity in the field by allowing thorough topsoil foraging, while genotypes with an exploratory root system may be advantageous if N or water is the limiting factor, although such genotypes showed highest P uptake levels under the artificial conditions of the present study. © The Author(s) 2018. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

    Directory of Open Access Journals (Sweden)

    Richard W Zobel

    2016-02-01

    Full Text Available 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 these classes of root. This then suggests that Arabidopsis root research can be considered an adequate model for eudicot plant root systems.

  12. 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. © 2015 American Society of Plant Biologists. All Rights Reserved.

  13. 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

  14. A Standardized Method to Assess Infection Rates of Root-Knot and Cyst Nematodes in Arabidopsis thaliana Mutants with Alterations in Root Development Related to Auxin and Cytokinin Signaling.

    Science.gov (United States)

    Olmo, Rocío; Silva, Ana Cláudia; Díaz-Manzano, Fernando E; Cabrera, Javier; Fenoll, Carmen; Escobar, Carolina

    2017-01-01

    Plant parasitic nematodes cause a great impact in agricultural systems. The search for effective control methods is partly based on the understanding of underlying molecular mechanisms leading to the formation of nematode feeding sites. In this respect, crosstalk of hormones such as auxins and cytokinins (IAA, CK) between the plant and the nematode seems to be crucial. Thence, the study of loss of function or overexpressing lines with altered IAA and CK functioning is entailed. Those lines frequently show developmental defects in the number, position and/or length of the lateral roots what could generate a bias in the interpretation of the nematode infection parameters. Here we present a protocol to assess differences in nematode infectivity with the lowest interference of root architecture phenotypes in the results. Thus, tailored growth conditions and normalization parameters facilitate the standardized phenotyping of nematode infection.

  15. 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.

  16. An L-system model for root system mycorrhization

    Science.gov (United States)

    Schnepf, Andrea; Schweiger, Peter; Jansa, Jan; Leitner, Daniel

    2014-05-01

    Mineral phosphate fertilisers are a non-renewable resource; rock phosphate reserves are estimated to be depleted in 50 to 100 years. In order to prevent a severe phosphate crisis in the 21st century, there is a need to decrease agricultural inputs such as P fertilisers by making use of plant mechanisms that increase P acquisition efficiency. Most plants establish mycorrhizal symbiosis as an adaptation to increase/economize their P acquisition from the soil. However, there is a great functional diversity in P acquisition mechanisms among different fungal species that colonize the roots (Thonar et al. 2011), and the composition of mycorrhizal community is known to depend strongly on agricultural management practices. Thus, the agroecosystem management may substantially affect the mycorrhizal functioning and also the use of P fertilizers. To date, it is still difficult to quantify the potential input savings for the agricultural crops through manipulation of their symbiotic microbiome, mainly due to lack of mechanistic understanding of P uptake dynamics by the fungal hyphae. In a first attempt, Schnepf et al. (2008b) have used mathematical modelling to show on the single root scale how different fungal growth pattern influence root P uptake. However, their approach was limited by the fact that it was restricted to the scale of a single root. The goal of this work is to advance the dynamic, three-dimensional root architecture model of Leitner et al. (2010) to include root system infection with arbuscular mycorrhizal fungi and growth of external mycelium. The root system infection model assumes that there is an average probability of infection (primary infection), that the probability of infection of a new root segment immediately adjacent to an existing infection is much higher than the average (secondary infection), that infected root segments have entry points that are the link between internal and external mycelium, that only uninfected root segments are susceptible

  17. 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.

  18. Air lateral root pruning affects longleaf pine seedling root system morphology

    Science.gov (United States)

    Shi-Jean Susana Sung; Dave Haywood

    2016-01-01

    Longleaf pine (Pinus palustris) seedlings were cultured with air lateral root pruning (side-vented containers, VT) or without (solid-walled containers, SW). Seedling root system morphology and growth were assessed before planting and 8 and 14 months after planting. Although VT seedlings had greater root collar diameter than the SW before planting,...

  19. GiA Roots: software for the high throughput analysis of plant root system architecture

    Science.gov (United States)

    2012-01-01

    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 for the high-throughput analysis of root system images. GiA Roots includes user-assisted algorithms to distinguish root from background and a fully automated pipeline that extracts dozens of root system phenotypes. Quantitative information on each phenotype, along with intermediate steps for full reproducibility, is returned to the end-user for downstream analysis. GiA Roots has a GUI front end and a command-line interface for interweaving the software into large-scale workflows. GiA Roots can also be extended to estimate novel phenotypes specified by the end-user. Conclusions We demonstrate the use of GiA Roots on a set of 2393 images of rice roots representing 12 genotypes from the species Oryza sativa. We validate trait measurements against prior analyses of this image set that demonstrated that RSA traits are likely heritable and associated with genotypic differences. Moreover, we demonstrate that GiA Roots is extensible and an end-user can add functionality so that GiA Roots can estimate novel RSA traits. In summary, we show that the software can function as an efficient tool as part of a workflow to move from large numbers of root images to downstream analysis. PMID:22834569

  20. 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. PMID:25566292

  1. Root water uptake and lateral interactions among root systems in a temperate forest

    Science.gov (United States)

    Agee, E.; He, L.; Bisht, G.; Gough, C. M.; Couvreur, V.; Matheny, A. M.; Bohrer, G.; Ivanov, V. Y.

    2016-12-01

    A growing body of research has highlighted the importance of root architecture and hydraulic properties to the maintenance of the transpiration stream under water limitation and drought. Detailed studies of single plant systems have shown the ability of root systems to adjust zones of uptake due to the redistribution of local water potential gradients, thereby delaying the onset of stress under drying conditions. An open question is how lateral interactions and competition among neighboring plants impact individual and community resilience to water stress. While computational complexity has previously hindered the implementation of microscopic root system structure and function in larger scale hydrological models, newer hybrid approaches allow for the resolution of these properties at the plot scale. Using a modified version of the PFLOTRAN model, which represents the 3-D physics of variably saturated soil, we model root water uptake in a one-hectare temperate forest plot under natural and synthetic forcings. Two characteristic hydraulic architectures, tap roots and laterally sprawling roots, are implemented in an ensemble of simulations. Variations of root architecture, their hydraulic properties, and degree of system interactions produce variable local response to water limitation and provide insights on individual and community response to changing meteorological conditions. Results demonstrate the ability of interacting systems to shift areas of active uptake based on local gradients, allowing individuals to meet water demands despite competition from their peers. These results further illustrate how inter- and intra-species variations in root properties may influence not only individual response to water stress, but also help quantify the margins of resilience for forest ecosystems under changing climate.

  2. Longleaf Pine Root System Development and Seedling Quality in Response to Copper Root Pruning and Cavity Size

    Science.gov (United States)

    Mary Anne Sword Sayer; Shi-Jean Susana Sung; James D. Haywood

    2011-01-01

    Cultural practices that modify root system structure in the plug of container-grown seedlings have the potential to improve root system function after planting. Our objective was to assess how copper root pruning affects the quality and root system development of longleaf pine seedlings grown in three cavity sizes in a greenhouse. Copper root pruning increased seedling...

  3. Root Systems of Individual Plants, and the Biotic and Abiotic Factors Controlling Their Depth and Distribution: a Synthesis Using a Global Database.

    Science.gov (United States)

    Tumber-Davila, S. J.; Schenk, H. J.; Jackson, R. B.

    2017-12-01

    This synthesis examines plant rooting distributions globally, by doubling the number of entries in the Root Systems of Individual Plants database (RSIP) created by Schenk and Jackson. Root systems influence many processes, including water and nutrient uptake and soil carbon storage. Root systems also mediate vegetation responses to changing climatic and environmental conditions. Therefore, a collective understanding of the importance of rooting systems to carbon sequestration, soil characteristics, hydrology, and climate, is needed. Current global models are limited by a poor understanding of the mechanisms affecting rooting, carbon stocks, and belowground biomass. This improved database contains an extensive bank of records describing the rooting system of individual plants, as well as detailed information on the climate and environment from which the observations are made. The expanded RSIP database will: 1) increase our understanding of rooting depths, lateral root spreads and above and belowground allometry; 2) improve the representation of plant rooting systems in Earth System Models; 3) enable studies of how climate change will alter and interact with plant species and functional groups in the future. We further focus on how plant rooting behavior responds to variations in climate and the environment, and create a model that can predict rooting behavior given a set of environmental conditions. Preliminary results suggest that high potential evapotranspiration and seasonality of precipitation are indicative of deeper rooting after accounting for plant growth form. When mapping predicted deep rooting by climate, we predict deepest rooting to occur in equatorial South America, Africa, and central India.

  4. Effect of localized nitrogen availability to soybean half-root systems on photosynthate partitioning to roots and nodules

    International Nuclear Information System (INIS)

    Singleton, P.W.; van Kessel, C.

    1987-01-01

    Soybean (Glycine max [L.] Merr. cv Davis) was grown in a split-root growth system designed to maintain control of the root atmosphere. Two experiments were conducted to examine how 80% Ar:20%, O 2 (Ar:O 2 ) and air (Air) atmospheres affected N assimilation (NH 4 NO 3 and N 2 fixation) and the partitioning of photosynthate to roots and nodules. Application of NH 4 NO 3 to nonnodulated half-root systems enhanced root growth and root respiration at the site of application. A second experiment applied Ar:O 2 or air to the two sides of nodulated soybean half-root systems for 11 days in the following combinations: (a) Air to both sides (Air/Air); (b) Air to one side, Ar:O 2 to the other (Air/Ar:O 2 ), and (c) Ar:O 2 to both sides (Ar:O 2 /Ar:O 2 ). Results indicated that dry matter and current photosynthate ( 14 C) were selectively partitioned to nodules and roots where N 2 was available. Both root and nodule growth on the Air side of Air/Ar:O 2 plants was significantly greater than the Ar:O 2 side. The relative partitioning of carbon and current photosynthate between roots and nodules on a half-root system was also affected by N 2 availability. The Ar:O 2 sides partitioned relatively more current photosynthate to roots (57%) than nodules (43%), while N 2 -fixing root systems partitioned 36 and 64% of the carbon to roots and nodules, respectively. The Ar:O 2 atmosphere decreased root and nodule respiration by 80% and nitrogenase activity by 85% compared to half-root systems in Air while specific nitrogenase activity in Ar:O 2 was 50% of nodules supplied Air. Results indicated that nitrogen assimilation, whether from N 2 fixation or inorganic sources, had a localized effect on root development

  5. Development and implementation of custom root-cause systems

    International Nuclear Information System (INIS)

    Paradies, M.; Unger, L.

    1990-01-01

    Almost anyone investigating an operating problem can expect their management and the US Nuclear Regulatory Commission (NRC) to ask them if they have really uncovered the root cause of the event. This paper outlines a proven method to develop a custom system to identify and analyze the root causes of events. The method has led to the successful implementation of root-cause analysis systems at the Savannah River Plant and at Philadelphia Electric's Peach Bottom and Limerick nuclear generating stations. The methods are currently being used by System Improvements to develop a root-cause system to be used by the NRC to identify human performance problems at utilities. This paper also outlines the common problems that may be encountered when implementing a root-cause program

  6. Elevated CO[sub 2] alters deployment of roots in small growth containers

    Energy Technology Data Exchange (ETDEWEB)

    Berntson, G M; McConnaughay, K D.M.; Bazzaz, F A [Harvard University, Cambridge, MA (United States). Dept. of Organismic and Evolutionary Biology

    1993-07-01

    Previously the authors examined how limited rooting space and nutrient supply influenced plant growth under elevated atmospheric CO[sub 2] concentrations. To gain insight into how elevated CO[sub 2] atmospheres affect how plants utilize available belowground space, when rooting space and nutrient supply are limited, they measured the deployment of roots within pots through time. Contrary to aboveground responses, patterns of belowground deployment were most strongly influenced by elevated CO[sub 2] in pots of different volume and shape. Further, elevated CO[sub 2] conditions interacted differently with limited belowground space for the two species studied, Abutilon theophrasti, a C[sub 3] dicot with a deep taproot, and Setaria faberii, a C4 monocot with a shallow fibrous root system. For Setaria, elevated CO[sub 2] increased the size of the largest region of low root density at the pot surface in larger rooting volumes independent of nutrient content, thereby decreasing their efficiency of deployment. For Abutilon, plants responded to elevated CO[sub 2] concentrations by equalizing the pattern of deployment in all the pots. Nutrient concentration, and not pot size or shape, greatly influenced the density of root growth. Root densities for Abutilon and Setaria were similar to those observed in field conditions, for annual dicots and monocots respectively, suggesting that studies using pots may successfully mimic natural conditions.

  7. Overexpression of Laccaria bicolor aquaporin JQ585595 alters root water transport properties in ectomycorrhizal white spruce (Picea glauca) seedlings.

    Science.gov (United States)

    Xu, Hao; Kemppainen, Minna; El Kayal, Walid; Lee, Seong Hee; Pardo, Alejandro G; Cooke, Janice E K; Zwiazek, Janusz J

    2015-01-01

    The contribution of hyphae to water transport in ectomycorrhizal (ECM) white spruce (Picea glauca) seedlings was examined by altering expression of a major water-transporting aquaporin in Laccaria bicolor. Picea glauca was inoculated with wild-type (WT), mock transgenic or L. bicolor aquaporin JQ585595-overexpressing (OE) strains and exposed to root temperatures ranging from 5 to 20°C to examine the root water transport properties, physiological responses and plasma membrane intrinsic protein (PIP) expression in colonized plants. Mycorrhization increased shoot water potential, transpiration, net photosynthetic rates, root hydraulic conductivity and root cortical cell hydraulic conductivity in seedlings. At 20°C, OE plants had higher root hydraulic conductivity compared with WT plants and the increases were accompanied by higher expression of P. glauca PIP GQ03401_M18.1 in roots. In contrast to WT L. bicolor, the effects of OE fungi on root and root cortical cell hydraulic conductivities were abolished at 10 and 5°C in the absence of major changes in the examined transcript levels of P. glauca root PIPs. The results provide evidence for the importance of fungal aquaporins in root water transport of mycorrhizal plants. They also demonstrate links between hyphal water transport, root aquaporin expression and root water transport in ECM plants. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  8. 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

  9. Root-Contact/Pressure-Plate Assembly For Hydroponic System

    Science.gov (United States)

    Morris, Carlton E.; Loretan, Philip A.; Bonsi, Conrad K.; Hill, Walter A.

    1994-01-01

    Hydroponic system includes growth channels equipped with rootcontact/pressure-plate assemblies. Pump and associated plumbing circulate nutrient liquid from reservoir, along bottom of growth channels, and back to reservoir. Root-contact/pressure-plate assembly in each growth channel stimulates growth of roots by applying mild contact pressure. Flat plate and plate connectors, together constitute pressure plate, free to move upward to accommodate growth of roots. System used for growing sweetpotatoes and possibly other tuber and root crops.

  10. Examining the Relationship Between Edaphic Variables and the Rooting System of Abies concolor in the southern Sierra Nevada

    Science.gov (United States)

    Wilson, A.; Jackson, R. B.; Tumber-Davila, S. J.

    2017-12-01

    An increase in the frequency and severity of droughts has been associated with the changing climate. These events have the potential to alter the composition and biogeography of forests, as well as increase tree mortality related to climate-induced stress. Already, an increase in tree mortality has been observed throughout the US. The recent drought in California led to millions of tree mortalities in the southern Sierra Nevada alone. In order to assess the potential impacts of these events on forest systems, it is imperative to understand what factors contribute to tree mortality. As plants become water-stressed, they may invest carbon more heavily belowground to reach a bigger pool of water, but their ability to adapt may be limited by the characteristics of the soil. In the Southern Sierra Critical Zone Observatory, a high tree mortality zone, we have selected both dead and living trees to examine the factors that contribute to root zone variability and belowground biomass investment by individual plants. A series of 15 cores surrounding the tree were taken to collect root and soil samples. These were then used to compare belowground rooting distributions with soil characteristics (texture, water holding capacity, pH, electric conductivity). Abies concolor is heavily affected by drought-induced mortality, therefore the rooting systems of dead Abies concolor trees were examined to determine the relationship between their rooting systems and environmental conditions. Examining the relationship between soil characteristics and rooting systems of trees may shed light on the plasticity of rooting systems and how trees adapt based on the characteristics of its environment. A better understanding of the factors that contribute to tree mortality can improve our ability to predict how forest systems may be impacted by climate-induced stress. Key words: Root systems, soil characteristics, drought, adaptation, terrestrial carbon, forest ecology

  11. S-nitrosoglutathione promotes cell wall remodelling, alters the transcriptional profile and induces root hair formation in the hairless root hair defective 6 (rhd6) mutant of Arabidopsis thaliana.

    Science.gov (United States)

    Moro, Camila Fernandes; Gaspar, Marilia; da Silva, Felipe Rodrigues; Pattathil, Sivakumar; Hahn, Michael G; Salgado, Ione; Braga, Marcia Regina

    2017-03-01

    Nitric oxide (NO) exerts pleiotropic effects on plant development; however, its involvement in cell wall modification during root hair formation (RHF) has not yet been addressed. Here, mutants of Arabidopsis thaliana with altered root hair phenotypes were used to assess the involvement of S-nitrosoglutathione (GSNO), the primary NO source, in cell wall dynamics and gene expression in roots induced to form hairs. GSNO and auxin restored the root hair phenotype of the hairless root hair defective 6 (rhd6) mutant. A positive correlation was observed between increased NO production and RHF induced by auxin in rhd6 and transparent testa glabra (ttg) mutants. Deposition of an epitope within rhamnogalacturonan-I recognized by the CCRC-M2 antibody was delayed in root hair cells (trichoblasts) compared with nonhair cells (atrichoblasts). GSNO, but not auxin, restored the wild-type root glycome and transcriptome profiles in rhd6, modulating the expression of a large number of genes related to cell wall composition and metabolism, as well as those encoding ribosomal proteins, DNA and histone-modifying enzymes and proteins involved in post-translational modification. Our results demonstrate that NO plays a key role in cell wall remodelling in trichoblasts and suggest that it also participates in chromatin modification in root cells of A. thaliana. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  12. Unleashing the potential of the root hair cell as a single plant cell type model in root systems biology

    Directory of Open Access Journals (Sweden)

    Zhenzhen eQiao

    2013-11-01

    Full Text Available Plant root is an organ composed of multiple cell types with different functions. This multicellular complexity limits our understanding of root biology because –omics studies performed at the level of the entire root reflect the average responses of all cells composing the organ. To overcome this difficulty and allow a more comprehensive understanding of root cell biology, an approach is needed that would focus on one single cell type in the plant root. Because of its biological functions (i.e. uptake of water and various nutrients; primary site of infection by nitrogen-fixing bacteria in legumes, the root hair cell is an attractive single cell model to study root cell response to various stresses and treatments. To fully study their biology, we have recently optimized procedures in obtaining root hair cell samples. We culture the plants using an ultrasound aeroponic system maximizing root hair cell density on the entire root systems and allowing the homogeneous treatment of the root system. We then isolate the root hair cells in liquid nitrogen. Isolated root hair yields could be up to 800 to 1000 mg of plant cells from 60 root systems. Using soybean as a model, the purity of the root hair was assessed by comparing the expression level of genes previously identified as soybean root hair specific between preparations of isolated root hair cells and stripped roots, roots devoid in root hairs. Enlarging our tests to include other plant species, our results support the isolation of large quantities of highly purified root hair cells which is compatible with a systems biology approach.

  13. 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...... growth rate up to 137% relative to non-inoculated control plants, evidence that plants respond to bacteria by modifying morphology. However, endophyte inoculation had no influence on total plant biomass and photosynthetic traits (net photosynthesis, chlorophyll content). In sum, bacterial inoculation did......Plant traits, such as root and leaf area, influence how plants interact with their environment and the diverse microbiota living within plants can influence plant morphology and physiology. Here, we explored how three bacterial strains isolated from the Populus root microbiome, influenced plant...

  14. Integration of root phenes revealed by intensive phenotyping of root system architecture, anatomy, and physiology in cereals

    Science.gov (United States)

    York, Larry

    2015-04-01

    Food insecurity is among the greatest challenges humanity will face in the 21st century. Agricultural production in much of the world is constrained by the natural infertility of soil which restrains crops from reaching their yield potential. In developed nations, fertilizer inputs pollute air and water and contribute to climate change and environmental degradation. In poor nations low soil fertility is a primary constraint to food security and economic development. Water is almost always limiting crop growth in any system. Increasing the acquisition efficiency of soil resources is one method by which crop yields could be increased without the use of more fertilizers or irrigation. Cereals are the most widely grown crops, both in terms of land area and in yield, so optimizing uptake efficiency of cereals is an important goal. Roots are the primary interface between plant and soil and are responsible for the uptake of soil resources. The deployment of roots in space and time comprises root system architecture (RSA). Cereal RSA is a complex phenotype that aggregates many elemental phenes (elemental units of phenotype). Integration of root phenes will be determined by interactions through their effects on soil foraging and plant metabolism. Many architectural, metabolic, and physiological root phenes have been identified in maize, including: nodal root number, nodal root growth angle, lateral root density, lateral root length, aerenchyma, cortical cell size and number, and nitrate uptake kinetics. The utility of these phenes needs confirmation in maize and in other cereals. The maize root system is composed of an embryonic root system and nodal roots that emerge in successive whorls as the plant develops, and is similar to other cereals. Current phenotyping platforms often ignore the inner whorls and instead focus on the most visible outer whorls after excavating a maize root crown from soil. Here, an intensive phenotyping platform evaluating phenes of all nodal root

  15. Wheat root length and not branching is altered in the presence of neighbours, including blackgrass.

    Directory of Open Access Journals (Sweden)

    Jessica A Finch

    Full Text Available The effect of neighbouring plants on crop root system architecture may directly interfere with water and nutrient acquisition, yet this important and interesting aspect of competition remains poorly understood. Here, the effect of the weed blackgrass (Alopecurus myosuroides Huds. on wheat (Triticum aestivum L. roots was tested, since a low density of this species (25 plants m-2 can lead to a 10% decrease in wheat yield and herbicide resistance is problematic. We used a simplified growth system based on gelled medium, to grow wheat alongside a neighbour, either another wheat plant, a blackgrass or Brachypodium dystachion individual (a model grass. A detailed analysis of wheat seminal root system architecture showed that the presence of a neighbour principally affected the root length, rather than number or diameter under a high nutrient regime. In particular, the length of first order lateral roots decreased significantly in the presence of blackgrass and Brachypodium. However, this effect was not noted when wheat plants were grown in low nutrient conditions. This suggests that wheat may be less sensitive to the presence of blackgrass when grown in low nutrient conditions. In addition, nutrient availability to the neighbour did not modulate the neighbour effect on wheat root architecture.

  16. Wheat root length and not branching is altered in the presence of neighbours, including blackgrass

    Science.gov (United States)

    Finch, Jessica A.; Guillaume, Gaëtan; French, Stephanie A.; Colaço, Renato D. D. R.; Davies, Julia M.

    2017-01-01

    The effect of neighbouring plants on crop root system architecture may directly interfere with water and nutrient acquisition, yet this important and interesting aspect of competition remains poorly understood. Here, the effect of the weed blackgrass (Alopecurus myosuroides Huds.) on wheat (Triticum aestivum L.) roots was tested, since a low density of this species (25 plants m-2) can lead to a 10% decrease in wheat yield and herbicide resistance is problematic. We used a simplified growth system based on gelled medium, to grow wheat alongside a neighbour, either another wheat plant, a blackgrass or Brachypodium dystachion individual (a model grass). A detailed analysis of wheat seminal root system architecture showed that the presence of a neighbour principally affected the root length, rather than number or diameter under a high nutrient regime. In particular, the length of first order lateral roots decreased significantly in the presence of blackgrass and Brachypodium. However, this effect was not noted when wheat plants were grown in low nutrient conditions. This suggests that wheat may be less sensitive to the presence of blackgrass when grown in low nutrient conditions. In addition, nutrient availability to the neighbour did not modulate the neighbour effect on wheat root architecture. PMID:28542446

  17. The MEDIATOR genes MED12 and MED13 control Arabidopsis root system configuration influencing sugar and auxin responses.

    Science.gov (United States)

    Raya-González, Javier; López-Bucio, Jesús Salvador; Prado-Rodríguez, José Carlos; Ruiz-Herrera, León Francisco; Guevara-García, Ángel Arturo; López-Bucio, José

    2017-09-01

    Arabidopsis med12 and med13 mutants exhibit shoot and root phenotypes related to an altered auxin homeostasis. Sucrose supplementation reactivates both cell division and elongation in primary roots as well as auxin-responsive and stem cell niche gene expression in these mutants. An analysis of primary root growth of WT, med12, aux1-7 and med12 aux1 single and double mutants in response to sucrose and/or N-1-naphthylphthalamic acid (NPA) placed MED12 upstream of auxin transport for the sugar modulation of root growth. The MEDIATOR (MED) complex plays diverse functions in plant development, hormone signaling and biotic and abiotic stress tolerance through coordination of transcription. Here, we performed genetic, developmental, molecular and pharmacological analyses to characterize the role of MED12 and MED13 on the configuration of root architecture and its relationship with auxin and sugar responses. Arabidopsis med12 and med13 single mutants exhibit shoot and root phenotypes consistent with altered auxin homeostasis including altered primary root growth, lateral root development, and root hair elongation. MED12 and MED13 were required for activation of cell division and elongation in primary roots, as well as auxin-responsive and stem cell niche gene expression. Remarkably, most of these mutant phenotypes were rescued by supplying sucrose to the growth medium. The growth response of primary roots of WT, med12, aux1-7 and med12 aux1 single and double mutants to sucrose and application of auxin transport inhibitor N-1-naphthylphthalamic acid (NPA) revealed the correlation of med12 phenotype with the activity of the auxin intake permease and suggests that MED12 acts upstream of AUX1 in the root growth response to sugar. These data provide compelling evidence that MEDIATOR links sugar sensing to auxin transport and distribution during root morphogenesis.

  18. Comparative study of six rotary nickel-titanium systems and hand instrumentation for root canal preparation.

    Science.gov (United States)

    Guelzow, A; Stamm, O; Martus, P; Kielbassa, A M

    2005-10-01

    To compare ex vivo various parameters of root canal preparation using a manual technique and six different rotary nickel-titanium (Ni-Ti) instruments (FlexMaster, System GT, HERO 642, K3, ProTaper, and RaCe). A total of 147 extracted mandibular molars were divided into seven groups (n = 21) with equal mean mesio-buccal root canal curvatures (up to 70 degrees), and embedded in a muffle system. All root canals were prepared to size 30 using a crown-down preparation technique for the rotary nickel-titanium instruments and a standardized preparation (using reamers and Hedströem files) for the manual technique. Length modifications and straightening were determined by standardized radiography and a computer-aided difference measurement for every instrument system. Post-operative cross-sections were evaluated by light-microscopic investigation and photographic documentation. Procedural errors, working time and time for instrumentation were recorded. The data were analysed statistically using the Kruskal-Wallis test and the Mann-Whitney U-test. No significant differences were detected between the rotary Ni-Ti instruments for alteration of working length. All Ni-Ti systems maintained the original curvature well, with minor mean degrees of straightening ranging from 0.45 degrees (System GT) to 1.17 degrees (ProTaper). ProTaper had the lowest numbers of irregular post-operative root canal diameters; the results were comparable between the other systems. Instrument fractures occurred with ProTaper in three root canals, whilst preparation with System GT, HERO 642, K3 and the manual technique resulted in one fracture each. Ni-Ti instruments prepared canals more rapidly than the manual technique. The shortest time for instrumentation was achieved with System GT (11.7 s). Under the conditions of this ex vivo study all Ni-Ti systems maintained the canal curvature, were associated with few instrument fractures and were more rapid than a standardized manual technique. Pro

  19. 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.

  20. Root Parameters Show How Management Alters Resource Distribution and Soil Quality in Conventional and Low-Input Cropping Systems in Central Iowa.

    Directory of Open Access Journals (Sweden)

    Patricia A Lazicki

    Full Text Available Plant-soil relations may explain why low-external input (LEI diversified cropping systems are more efficient than their conventional counterparts. This work sought to identify links between management practices, soil quality changes, and root responses in a long-term cropping systems experiment in Iowa where grain yields of 3-year and 4-year LEI rotations have matched or exceeded yield achieved by a 2-year maize (Zea mays L. and soybean (Glycine max L. rotation. The 2-year system was conventionally managed and chisel-ploughed, whereas the 3-year and 4-year systems received plant residues and animal manures and were periodically moldboard ploughed. We expected changes in soil quality to be driven by organic matter inputs, and root growth to reflect spatial and temporal fluctuations in soil quality resulting from those additions. We constructed a carbon budget and measured soil quality indicators (SQIs and rooting characteristics using samples taken from two depths of all crop-phases of each rotation system on multiple dates. Stocks of particulate organic matter carbon (POM-C and potentially mineralizable nitrogen (PMN were greater and more evenly distributed in the LEI than conventional systems. Organic C inputs, which were 58% and 36% greater in the 3-year rotation than in the 4-year and 2-year rotations, respectively, did not account for differences in SQI abundance or distribution. Surprisingly, SQIs did not vary with crop-phase or date. All biochemical SQIs were more stratified (p<0.001 in the conventionally-managed soils. While POM-C and PMN in the top 10 cm were similar in all three systems, stocks in the 10-20 cm depth of the conventional system were less than half the size of those found in the LEI systems. This distribution was mirrored by maize root length density, which was also concentrated in the top 10 cm of the conventionally managed plots and evenly distributed between depths in the LEI systems. The plow-down of organic amendments

  1. Maize root culture as a model system for studying azoxystrobin biotransformation in plants

    DEFF Research Database (Denmark)

    Gautam, Maheswor; Elhiti, Mohamed Abdelsamad A; Fomsgaard, Inge S.

    2018-01-01

    Hairy roots induced by Agrobacterium rhizogenes are well established models to study the metabolism of xenobiotics in plants for phytoremediation purposes. However, the model requires special skills and resources for growing and is a time-consuming process. The roots induction process alters...... the genetic construct of a plant and is known to express genes that are normally absent from the non-transgenic plants. In this study, we propose and establish a non-transgenic maize root model to study xenobiotic metabolism in plants for phytoremediation purpose using azoxystrobin as a xenobiotic compound...

  2. Elliptic hypergeometric functions associated with root systems

    OpenAIRE

    Rosengren, Hjalmar; Warnaar, S. Ole

    2017-01-01

    We give a survey of elliptic hypergeometric functions associated with root systems, comprised of three main parts. The first two form in essence an annotated table of the main evaluation and transformation formulas for elliptic hypergeometric integeral and series on root systems. The third and final part gives an introduction to Rains' elliptic Macdonald-Koornwinder theory (in part also developed by Coskun and Gustafson).

  3. Tree root systems and nutrient mobilization

    DEFF Research Database (Denmark)

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

    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......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...

  4. Root carbon input in organic and inorganic fertilizer-based systems

    DEFF Research Database (Denmark)

    Chirinda, Ngoni; Olesen, Jørgen E; Porter, John

    2012-01-01

    C input to remain scant. This study aimed at determining macro-root C input and topsoil root related respiration in response to nutrient management and soil fertility building measures. Methods We sampled roots and shoots of cereals and catch crops in inorganic and organic fertilizer-based arable...... season of winter wheat by subtracting soil respiration from soil with and without exclusion of roots. Results Catch crop roots accounted for more than 40 % of total plant C. For spring barley in 2008 and spring wheat in 2010, root C was higher in the organic than in the inorganic fertilizer-based systems...... was higher (31–131 %) in inorganic than in organic fertilizer-based systems. Conclusions Our findings show that macro-roots of both cereal crops and catch crops play a relatively larger role in organically managed systems than in mineral fertilizer based systems; and that the use of fixed biomass S/R ratios...

  5. Rooting depth and root depth distribution of Trifolium repens × T. uniflorum interspecific hybrids.

    Science.gov (United States)

    Nichols, S N; Hofmann, R W; Williams, W M; van Koten, C

    2016-05-20

    Traits related to root depth distribution were examined in Trifolium repens × T. uniflorum backcross 1 (BC 1 ) hybrids to determine whether root characteristics of white clover could be improved by interspecific hybridization. Two white clover cultivars, two T. uniflorum accessions and two BC 1 populations were grown in 1 -m deep tubes of sand culture. Maximum rooting depth and root mass distribution were measured at four harvests over time, and root distribution data were fitted with a regression model to provide measures of root system shape. Morphological traits were measured at two depths at harvest 3. Root system shape of the hybrids was more similar to T. uniflorum than to white clover. The hybrids and T. uniflorum had a higher rate of decrease in root mass with depth than white clover, which would result in higher proportions of root mass in the upper profile. Percentage total root mass at 100-200 mm depth was higher for T. uniflorum than white clover, and for Crusader BC 1 than 'Crusader'. Roots of the hybrids and T. uniflorum also penetrated deeper than those of white clover. T. uniflorum had thicker roots at 50-100 mm deep than the other entries, and more of its fine root mass at 400-500 mm. The hybrids and white clover had more of their fine root mass higher in the profile. Consequently, T. uniflorum had a higher root length density at 400-500 mm than most entries, and a smaller decrease in root length density with depth. These results demonstrate that rooting characteristics of white clover can be altered by hybridization with T. uniflorum, potentially improving water and nutrient acquisition and drought resistance. Root traits of T. uniflorum are likely to be adaptations to soil moisture and fertility in its natural environment. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Property ($T$) for groups graded by root systems

    CERN Document Server

    Ershov, Mikhail; Kassabov, Martin

    2017-01-01

    The authors introduce and study the class of groups graded by root systems. They prove that if \\Phi is an irreducible classical root system of rank \\geq 2 and G is a group graded by \\Phi, then under certain natural conditions on the grading, the union of the root subgroups is a Kazhdan subset of G. As the main application of this theorem the authors prove that for any reduced irreducible classical root system \\Phi of rank \\geq 2 and a finitely generated commutative ring R with 1, the Steinberg group {\\mathrm St}_{\\Phi}(R) and the elementary Chevalley group \\mathbb E_{\\Phi}(R) have property (T). They also show that there exists a group with property (T) which maps onto all finite simple groups of Lie type and rank \\geq 2, thereby providing a "unified" proof of expansion in these groups.

  7. Root cause of failure analysis and the system engineer

    International Nuclear Information System (INIS)

    Coppock, M.S.; Hartwig, A.W.

    1990-01-01

    In an industry where ever-increasing emphasis is being placed on root cause of failure determination, it is imperative that a successful nuclear utility have an effective means of identifying failures and performing the necessary analyses. The current Institute of Nuclear Power Operations (INPO) good practice, OE-907, root-cause analysis, gives references to methodology that will help determine breakdowns in procedures, programs, or design but gives very little guidance on how or when to perform component root cause of failure analyses. The system engineers of nuclear utilities are considered the focal point for their respective systems and are required by most programs to investigate component failures. The problem that the system engineer faces in determining a component root cause of failures lies in acquisition of the necessary data to identify the need to perform the analysis and in having the techniques and equipment available to perform it. The system engineers at the Palo Verde nuclear generating station routinely perform detailed component root cause of failure analyses. The Palo Verde program provides the system engineers with the information necessary to identify when a component root cause of failure is required. Palo Verde also has the necessary equipment on-site to perform the analyses

  8. Influence of the rotary and/or oscillatory reciprocating systems in the morphological changes of narrow and curved molar root canals anatomy

    Directory of Open Access Journals (Sweden)

    Joedy Maria Costa Santa Rosa

    Full Text Available OBJECTIVE: This study evaluated four mechanized Endodontic systems, ProTaper Universal, K3 Endo, Twisted file (rotary and the oscillatory reciprocating system Endo - Eze TiLOS, in order to verify and measure alterations in original anatomy with deviations at cervical, medium and apical root canal thirds. MATERIAL AND METHOD: It was used MB root canals of 60 extract human lower molars, to produce a line of severe angles, according to the classification of Schneider. Samples were included in Ester vinyl resin, mounted in the Teflon Furnace, transversally sectioned at the cervical, middle and apical thirds, which were subsequently photographed using a digital camera Cyber Shot DSC-TX10,attached to an operating microscope 3101XY DFVasconcelos with 40× magnification in order to measure the anatomical transversal area of the root canal, using the software AutoCAD 2008, comparing pre and post-instrumentation. All samples assembled in the Furnace also were submitted to x-ray in a standardized way to enable the comparison of the angle of Schneider pre-and post-instrumentation. Once collected the data, they were compared statistically using the program BioEstat 5.0. RESULT: The analysis of the results showed that in the cervical third, rotary systems were more effective than Endo-Eze TiLOS System with statistically significant differences (p ≤ 0,05. Apical and middle third changes in anatomy were similar, but apically, the ProTaper system caused more deviations when comparing the angle of Schneider,and areas before and after instrumentation(p ≤ 0,05. CONCLUSION: It was concluded that all the systems caused alteration in the original anatomy of the root canal when parameters as angle of Schneider and areas before and after preparation were used.

  9. Evaluation of the morphological alteration of the root surface radiated with a diode laser

    International Nuclear Information System (INIS)

    Gulin, Mauricio

    2003-01-01

    The diode laser has been studied for periodontal therapy, as much for removal of calculus as for microbial reduction of periodontal pockets, as well as the visible analgesic effects and biomodulation capacity. For this reason the purpose of this study was to evaluate the morphological alteration of the root surface after radiation with the diode laser, 808 nm through analysis by scanning electron microscopy (SEM). Besides this, to verify the temperature variations caused during the radiation, a thermometer put into the dentinal wall of the root canal was used. In all, 18 teeth were used, 15 of which for the SEM study, and the other 3 were used to temperature variation analysis. The 25 samples were scraped on the root surface and planed with manual instruments. The other 5 were not subjected to any type of treatment. This, 6 groups of 5 samples each were formed. Control Group C whose samples had not received any treatment; Control Group C 1 was only scraped and polished conventionally with Hu-Friedy Gracey curettes 5 and 6; the other samples groups L1, L2, L3, L4 were radiated by diode laser using parameters of power 1,0 W; 1,2 W; 1,4 W; and 1,6 W respectively, 2 times for 10 seconds with 20 seconds intervals between each radiation in continuous mode. The results with relation to the increase of temperature in the interior of the root canal demonstrated that there was an increase of more than 5 degree Celsius. The results of the scanning electron microscope analysis of Control Group C demonstrated great irregularity and ridges on the root surface, with the presence of a dentine layer. Control Group C1 presented a similar aspect to Group L 1's, smoother and more homogeneous surface. Groups L2, L3, and L4 presented scratches alternating with smoother areas showing that fiber contacted the surface of the sample. The results reconfirmed the necessity of further studies using diode laser, with a beam of light emitted in an interrupted mode to improve the control of the

  10. The Usage of ROOT in the LHCb Online System

    CERN Document Server

    Frank, M

    2013-01-01

    The online system in the LHCb experiment uses ROOT in various areas. ROOT is used in all processes participating in event data processing. The degree of usage varies quite significantly - from the very rudimentary usage of the ROOT plugin mechanism to fully equipped applications filling histograms with data describing online the detector status for monitoring purposes and the display of these data. An increasing number of processes uses the python binding offered by PyROOT to configure these processes. PyROOT also allows to efficiently and quickly manipulate certain corners of the experiment controls system where necessary. Beside these areas, where the LHCb online team advocated the usage of ROOT, in other areas other technologies were chosen. These deliberate choices like e.g. in the area of persistency of event data from particle collisions will be discussed.

  11. Compost and biochar alter mycorrhization, tomato root exudation and development of Fusarium oxysporum f. sp. lycopersici

    Directory of Open Access Journals (Sweden)

    Adnan eAkhter

    2015-07-01

    Full Text Available Soil amendments like compost and biochar are known to affect soil properties, plant growth as well as soil borne plant pathogens. Complex interactions based on microbial activity and abiotic characteristics are supposed to be responsible for suppressive properties of certain substrates, however, the specific mechanisms of action are still widely unknown. In the present study, the main focus was on the development of the soil borne pathogen, Fusarium oxysporum f.sp. lycopersici (Fol in tomato (Solanum lycopersicum L. and changes in root exudates of tomato plants grown in different soil substrate compositions, such as compost (Comp alone at application rate of 20 % (v/v, and in combination with wood biochar (WB; made from beech wood chips or green waste biochar (GWB, made from garden waste residues at application rate of 3 % (v/v, and/or with additional arbuscular mycorrhizal fungi (AMF. The association of GWB and AMF had a positive effect on tomato plants growth unlike to the plants grown in WB containing soil substrate. The AMF root colonization was not enhanced by the addition of WB or GWB in the soil substrate, though bio-protective effect of mycorrhization was evident in both biochar amended treatments against Fol. Compost and biochars altered root exudates differently, which is evident from variable response of in vitro growth and development of Fol. The microconidia germination was highest under in root exudates from plants grown in the soil containing compost and GWB, whereas root exudates of plants from substrate containing WB suppressed the mycelial growth and development of Fol. In conclusion, the plant growth response and disease suppression in biochar containing substrates with additional AMF was affected by the feedstock type. Moreover, application of compost and biochars in the soil influence the quality and composition of root exudates with respect to their effects on soil-dwelling fungi.

  12. A Pipeline for 3D Digital Optical Phenotyping Plant Root System Architecture

    Science.gov (United States)

    Davis, T. W.; Shaw, N. M.; Schneider, D. J.; Shaff, J. E.; Larson, B. G.; Craft, E. J.; Liu, Z.; Kochian, L. V.; Piñeros, M. A.

    2017-12-01

    This work presents a new pipeline for digital optical phenotyping the root system architecture of agricultural crops. The pipeline begins with a 3D root-system imaging apparatus for hydroponically grown crop lines of interest. The apparatus acts as a self-containing dark room, which includes an imaging tank, motorized rotating bearing and digital camera. The pipeline continues with the Plant Root Imaging and Data Acquisition (PRIDA) software, which is responsible for image capturing and storage. Once root images have been captured, image post-processing is performed using the Plant Root Imaging Analysis (PRIA) command-line tool, which extracts root pixels from color images. Following the pre-processing binarization of digital root images, 3D trait characterization is performed using the next-generation RootReader3D software. RootReader3D measures global root system architecture traits, such as total root system volume and length, total number of roots, and maximum rooting depth and width. While designed to work together, the four stages of the phenotyping pipeline are modular and stand-alone, which provides flexibility and adaptability for various research endeavors.

  13. 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....

  14. Root systems and soil microbial biomass under no-tillage system

    Directory of Open Access Journals (Sweden)

    Venzke Filho Solismar de Paiva

    2004-01-01

    Full Text Available Some root parameters such as distribution, length, diameter and dry matter are inherent to plant species. Roots can influence microbial population during vegetative cycle through the rhizodeposits and, after senescence, integrating the soil organic matter pool. Since they represent labile substrates, especially regarding nitrogen, they can determine the rate of nutrient availability to the next crop cultivated under no-tillage (NT. The root systems of two crop species: maize (Zea mays L. cultivar Cargill 909 and soybean [Glycine max (L. Merr.] cultivar Embrapa 59, were compared in the field, and their influence on spatial distribution of the microbial C and N in a clayey-textured Typic Hapludox cultivated for 22 years under NT, at Tibagi, State of Paraná (PR, Brazil, was determined. Digital image processing and nail-plate techniques were used to evaluate 40 plots of a 80 ´ 50 ´ 3 cm soil profile. It was observed that 36% and 30% of the maize and soybeans roots, respectively, are concentrated in the 0 to 10 cm soil layer. The percent distribution of root dry matter was similar for both crops. The maize roots presented a total of 1,324 kg C ha-1 and 58 kg N ha-1, with higher root dry matter density and more roots in decomposition in the upper soil layer, decreasing with depth. The soybean roots (392 kg C ha-1 and 21 kg N ha-1 showed higher number of thinner roots and higher density per length unity compared to the maize. The maize roots enhanced microbial-C down to deeper soil layers than did the soybean roots. The microbial N presented a better correlation with the concentration of thin active roots and with roots in decomposition or in indefinite shape, possibly because of higher concentration of C and N easily assimilated by soil microorganisms.

  15. Novel scanning procedure enabling the vectorization of entire rhizotron-grown root systems

    Directory of Open Access Journals (Sweden)

    Lobet Guillaume

    2013-01-01

    Full Text Available Abstract This paper presents an original spit-and-combine imaging procedure that enables the complete vectorization of complex root systems grown in rhizotrons. The general principle of the method is to (1 separate the root system into a small number of large pieces to reduce root overlap, (2 scan these pieces one by one, (3 analyze separate images with a root tracing software and (4 combine all tracings into a single vectorized root system. This method generates a rich dataset containing morphological, topological and geometrical information of entire root systems grown in rhizotrons. The utility of the method is illustrated with a detailed architectural analysis of a 20-day old maize root system, coupled with a spatial analysis of water uptake patterns.

  16. Novel scanning procedure enabling the vectorization of entire rhizotron-grown root systems.

    Science.gov (United States)

    Lobet, Guillaume; Draye, Xavier

    2013-01-04

    : This paper presents an original spit-and-combine imaging procedure that enables the complete vectorization of complex root systems grown in rhizotrons. The general principle of the method is to (1) separate the root system into a small number of large pieces to reduce root overlap, (2) scan these pieces one by one, (3) analyze separate images with a root tracing software and (4) combine all tracings into a single vectorized root system. This method generates a rich dataset containing morphological, topological and geometrical information of entire root systems grown in rhizotrons. The utility of the method is illustrated with a detailed architectural analysis of a 20-day old maize root system, coupled with a spatial analysis of water uptake patterns.

  17. 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. Copyright © 2015 Elsevier GmbH. All rights reserved.

  18. Root system-based limits to agricultural productivity and efficiency: the farming systems context

    Science.gov (United States)

    Thorup-Kristensen, Kristian; Kirkegaard, John

    2016-01-01

    Background There has been renewed global interest in both genetic and management strategies to improve root system function in order to improve agricultural productivity and minimize environmental damage. Improving root system capture of water and nutrients is an obvious strategy, yet few studies consider the important interactions between the genetic improvements proposed, and crop management at a system scale that will influence likely success. Scope To exemplify these interactions, the contrasting cereal-based farming systems of Denmark and Australia were used, where the improved uptake of water and nitrogen from deeper soil layers has been proposed to improve productivity and environmental outcomes in both systems. The analysis showed that water and nitrogen availability, especially in deeper layers (>1 m), was significantly affected by the preceding crops and management, and likely to interact strongly with deeper rooting as a specific trait of interest. Conclusions In the semi-arid Australian environment, grain yield impacts from storage and uptake of water from depth (>1 m) could be influenced to a stronger degree by preceding crop choice (0·42 t ha–1), pre-crop fallow management (0·65 t ha–1) and sowing date (0·63 t ha–1) than by current genetic differences in rooting depth (0·36 t ha–1). Matching of deep-rooted genotypes to management provided the greatest improvements related to deep water capture. In the wetter environment of Denmark, reduced leaching of N was the focus. Here the amount of N moving below the root zone was also influenced by previous crop choice or cover crop management (effects up to 85 kg N ha–1) and wheat crop sowing date (up to 45 kg ha–1), effects which over-ride the effects of differences in rooting depth among genotypes. These examples highlight the need to understand the farming system context and important G × E × M interactions in studies on proposed genetic improvements to root systems for improved

  19. Primary root protophloem differentiation requires balanced phosphatidylinositol-4,5-biphosphate levels and systemically affects root branching.

    Science.gov (United States)

    Rodriguez-Villalon, Antia; Gujas, Bojan; van Wijk, Ringo; Munnik, Teun; Hardtke, Christian S

    2015-04-15

    Protophloem is a specialized vascular tissue in growing plant organs, such as root meristems. In Arabidopsis mutants with impaired primary root protophloem differentiation, brevis radix (brx) and octopus (ops), meristematic activity and consequently overall root growth are strongly reduced. Second site mutation in the protophloem-specific presumed phosphoinositide 5-phosphatase cotyledon vascular pattern 2 (CVP2), but not in its homolog CVP2-like 1 (CVL1), partially rescues brx defects. Consistent with this finding, CVP2 hyperactivity in a wild-type background recreates a brx phenotype. Paradoxically, however, while cvp2 or cvl1 single mutants display no apparent root defects, the root phenotype of cvp2 cvl1 double mutants is similar to brx or ops, although, as expected, cvp2 cvl1 seedlings contain more phosphatidylinositol-4,5-biphosphate. Thus, tightly balanced phosphatidylinositol-4,5-biphosphate levels appear essential for proper protophloem differentiation. Genetically, OPS acts downstream of phosphatidylinositol-4,5-biphosphate levels, as cvp2 mutation cannot rescue ops defects, whereas increased OPS dose rescues cvp2 cvl1 defects. Finally, all three mutants display higher density and accelerated emergence of lateral roots, which correlates with increased auxin response in the root differentiation zone. This phenotype is also created by application of peptides that suppress protophloem differentiation, clavata3/embryo surrounding region 26 (CLE26) and CLE45. Thus, local changes in the primary root protophloem systemically shape overall root system architecture. © 2015. Published by The Company of Biologists Ltd.

  20. Molecular Physiology of Root System Architecture in Model Grasses

    Science.gov (United States)

    Hixson, K.; Ahkami, A. H.; Anderton, C.; Veličković, D.; Myers, G. L.; Chrisler, W.; Lindenmaier, R.; Fang, Y.; Yabusaki, S.; Rosnow, J. J.; Farris, Y.; Khan, N. E.; Bernstein, H. C.; Jansson, C.

    2017-12-01

    Unraveling the molecular and physiological mechanisms involved in responses of Root System Architecture (RSA) to abiotic stresses and shifts in microbiome structure is critical to understand and engineer plant-microbe-soil interactions in the rhizosphere. In this study, accessions of Brachypodium distachyon Bd21 (C3 model grass) and Setaria viridis A10.1 (C4 model grass) were grown in phytotron chambers under current and elevated CO2 levels. Detailed growth stage-based phenotypic analysis revealed different above- and below-ground morphological and physiological responses in C3 and C4 grasses to enhanced CO2 levels. Based on our preliminary results and by screening values of total biomass, water use efficiency, root to shoot ratio, RSA parameters and net assimilation rates, we postulated a three-phase physiological mechanism, i.e. RootPlus, BiomassPlus and YieldPlus phases, for grass growth under elevated CO2 conditions. Moreover, this comprehensive set of morphological and process-based observations are currently in use to develop, test, and calibrate biophysical whole-plant models and in particular to simulate leaf-level photosynthesis at various developmental stages of C3 and C4 using the model BioCro. To further link the observed phenotypic traits at the organismal level to tissue and molecular levels, and to spatially resolve the origin and fate of key metabolites involved in primary carbohydrate metabolism in different root sections, we complement root phenotypic observations with spatial metabolomics data using mass spectrometry imaging (MSI) methods. Focusing on plant-microbe interactions in the rhizosphere, six bacterial strains with plant growth promoting features are currently in use in both gel-based and soil systems to screen root growth and development in Brachypodium. Using confocal microscopy, GFP-tagged bacterial systems are utilized to study the initiation of different root types of RSA, including primary root (PR), coleoptile node axile root (CNR

  1. Effects of 4-phenyl butyric acid on high glucose-induced alterations in dorsal root ganglion neurons.

    Science.gov (United States)

    Sharma, Dilip; Singh, Jitendra Narain; Sharma, Shyam S

    2016-12-02

    Mechanisms and pathways involving in diabetic neuropathy are still not fully understood but can be unified by the process of overproduction of reactive oxygen species (ROS) such as superoxide, endoplasmic reticulum (ER) stress, downstream intracellular signaling pathways and their modulation. Susceptibility of dorsal root ganglion (DRG) to internal/external hyperglycemic environment stress contributes to the pathogenesis and progression of diabetic neuropathy. ER stress leads to abnormal ion channel function, gene expression, transcriptional regulation, metabolism and protein folding. 4-phenyl butyric acid (4-PBA) is a potent and selective chemical chaperone; which may inhibit ER stress. It may be hypothesized that 4-PBA could attenuate via channels in DRG in diabetic neuropathy. Effects of 4-PBA were determined by applying different parameters of oxidative stress, cell viability, apoptosis assays and channel expression in cultured DRG neurons. Hyperglycemia-induced apoptosis in the DRG neuron was inhibited by 4-PBA. Cell viability of DRG neurons was not altered by 4-PBA. Oxidative stress was significantly blocked by the 4-PBA. Sodium channel expression was not altered by the 4-PBA. Our data provide evidence that the hyperglycemia-induced alteration may be reduced by the 4-PBA without altering the sodium channel expression. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  2. Localized iron supply triggers lateral root elongation in Arabidopsis by altering the AUX1-mediated auxin distribution.

    Science.gov (United States)

    Giehl, Ricardo F H; Lima, Joni E; von Wirén, Nicolaus

    2012-01-01

    Root system architecture depends on nutrient availability, which shapes primary and lateral root development in a nutrient-specific manner. To better understand how nutrient signals are integrated into root developmental programs, we investigated the morphological response of Arabidopsis thaliana roots to iron (Fe). Relative to a homogeneous supply, localized Fe supply in horizontally separated agar plates doubled lateral root length without having a differential effect on lateral root number. In the Fe uptake-defective mutant iron-regulated transporter1 (irt1), lateral root development was severely repressed, but a requirement for IRT1 could be circumvented by Fe application to shoots, indicating that symplastic Fe triggered the local elongation of lateral roots. The Fe-stimulated emergence of lateral root primordia and root cell elongation depended on the rootward auxin stream and was accompanied by a higher activity of the auxin reporter DR5-β-glucuronidase in lateral root apices. A crucial role of the auxin transporter AUXIN RESISTANT1 (AUX1) in Fe-triggered lateral root elongation was indicated by Fe-responsive AUX1 promoter activities in lateral root apices and by the failure of the aux1-T mutant to elongate lateral roots into Fe-enriched agar patches. We conclude that a local symplastic Fe gradient in lateral roots upregulates AUX1 to accumulate auxin in lateral root apices as a prerequisite for lateral root elongation.

  3. Composite potato plants with transgenic roots on non-transgenic shoots: a model system for studying gene silencing in roots.

    Science.gov (United States)

    Horn, Patricia; Santala, Johanna; Nielsen, Steen Lykke; Hühns, Maja; Broer, Inge; Valkonen, Jari P T

    2014-12-01

    Composite potato plants offer an extremely fast, effective and reliable system for studies on gene functions in roots using antisense or inverted-repeat but not sense constructs for gene inactivation. Composite plants, with transgenic roots on a non-transgenic shoot, can be obtained by shoot explant transformation with Agrobacterium rhizogenes. The aim of this study was to generate composite potato plants (Solanum tuberosum) to be used as a model system in future studies on root-pathogen interactions and gene silencing in the roots. The proportion of transgenic roots among the roots induced was high (80-100%) in the four potato cultivars tested (Albatros, Desirée, Sabina and Saturna). No wild-type adventitious roots were formed at mock inoculation site. All strains of A. rhizogenes tested induced phenotypically normal roots which, however, showed a reduced response to cytokinin as compared with non-transgenic roots. Nevertheless, both types of roots were infected to a similar high rate with the zoospores of Spongospora subterranea, a soilborne potato pathogen. The transgenic roots of composite potato plants expressed significantly higher amounts of β-glucuronidase (GUS) than the roots of a GUS-transgenic potato line event. Silencing of the uidA transgene (GUS) was tested by inducing roots on the GUS-transgenic cv. Albatros event with strains of A. rhizogenes over-expressing either the uidA sense or antisense transcripts, or inverted-repeat or hairpin uidA RNA. The three last mentioned constructs caused 2.5-4.0 fold reduction in the uidA mRNA expression. In contrast, over-expression of uidA resulted in over 3-fold increase in the uidA mRNA and GUS expression, indicating that sense-mediated silencing (co-suppression) was not functional in roots. The results suggest that composite plants offer a useful experimental system for potato research, which has gained little previous attention.

  4. The distribution of 32P in the rice plant applied to a single root and to the whole root system

    International Nuclear Information System (INIS)

    Sisworo, E.L.; Gandanegara, S.; Sisworo, W.H.; Rasyid, H.; Sumarna, Nana

    1982-01-01

    Two greenhouse experiments to study the distribution of 32 P applied to a single root and to the whole root system have been carried out. Data from experiment 1 showed that 32 P activity in shoots rose with the progress of time; where 32 P was applied to a single root 6 hours after isotope application the 32 P activity in the shoots of plants was higher than if the isotope was applied to the whole root system. Three hours after 32 P application, plants with 50% of roots had a higher 32 P activity than plants with no root cutting. Data from experiment 2 showed that 32 P activity of plants that received 32 P through a single root only was lower than those that received 32 P through the whole root system. This was in contradiction with the data obtained in experiment 1. Experiment 2 also showed that 32 P activity increased with time. Autoradiographs of plants in experiment 1 and 2 showed that 32 P was distributed through the whole plant, although when the isotope was only applied to a single root. (author)

  5. Non-Hermitian multi-particle systems from complex root spaces

    International Nuclear Information System (INIS)

    Fring, Andreas; Smith, Monique

    2012-01-01

    We provide a general construction procedure for antilinearly invariant complex root spaces. The proposed method is generic and may be applied to any Weyl group allowing us to take any element of the group as a starting point for the construction. Worked-out examples for several specific Weyl groups are presented, focusing especially on those cases for which no solutions were found previously. When applied to the defining relations of models based on root systems, this usually leads to non-Hermitian models, which are nonetheless physically viable in a self-consistent sense as they are antilinearly invariant by construction. We discuss new types of Calogero models based on these complex roots. In addition, we propose an alternative construction leading to q-deformed roots. We employ the latter type of roots to formulate a new version of affine Toda field theories based on non-simply laced root systems. These models exhibit on the classical level a strong–weak duality in the coupling constant equivalent to a Lie algebraic duality, which is known for the quantum version of the undeformed case. (paper)

  6. C-SHAPED CONFIGURATION OF THE ROOT CANAL SYSTEM – PROBLEMS AND SOLUTIONS.

    Directory of Open Access Journals (Sweden)

    Janet Kirilova

    2014-06-01

    Full Text Available Introduction: The patients with C-shaped configuration of the root canal system are definitely a problem in the everyday dental practice. The C-shaped configuration of the root canal can be seen in the mandibular and maxillary molars. The treatment of these teeth is very difficult. Purpose: To trace the treatment of clinical cases with C-shaped configuration of the root canal system. Material and methods: There are some different cases that are described with a C-shaped configuration of the root canal system with one, two, three and four separate root canals. Careful exploration of the floor of the pulp chamber, inspection with magnification, use of ultrasonic irrigation and a modified filling technique are of particular use. Results and Discussion: Clinical cases of a C-shaped pulp chamber and root canal system shows that this root canal aberration occurs in a wide variety and variability with a single root canal up to two, three and four separate root canals. The diameter of the root canal themselves also varies from very wide to such with a small diameter. Conclusions: Knowledge of the different anatomical variations will improve the endododntic practice of the general dental practitioners.

  7. Foxtail Millet [Setaria italica (L. Beauv.] Grown under Low Nitrogen Shows a Smaller Root System, Enhanced Biomass Accumulation, and Nitrate Transporter Expression

    Directory of Open Access Journals (Sweden)

    Faisal Nadeem

    2018-02-01

    Full Text Available Foxtail millet (FM [Setaria italica (L. Beauv.] is a grain and forage crop well adapted to nutrient-poor soils. To date little is known how FM adapts to low nitrogen (LN at the morphological, physiological, and molecular levels. Using the FM variety Yugu1, we found that LN led to lower chlorophyll contents and N concentrations, and higher root/shoot and C/N ratios and N utilization efficiencies under hydroponic culture. Importantly, enhanced biomass accumulation in the root under LN was in contrast to a smaller root system, as indicated by significant decreases in total root length; crown root number and length; and lateral root number, length, and density. Enhanced carbon allocation toward the root was rather for significant increases in average diameter of the LN root, potentially favorable for wider xylem vessels or other anatomical alterations facilitating nutrient transport. Lower levels of IAA and CKs were consistent with a smaller root system and higher levels of GA may promote root thickening under LN. Further, up-regulation of SiNRT1.1, SiNRT2.1, and SiNAR2.1 expression and nitrate influx in the root and that of SiNRT1.11 and SiNRT1.12 expression in the shoot probably favored nitrate uptake and remobilization as a whole. Lastly, more soluble proteins accumulated in the N-deficient root likely as a result of increases of N utilization efficiencies. Such “excessive” protein-N was possibly available for shoot delivery. Thus, FM may preferentially transport carbon toward the root facilitating root thickening/nutrient transport and allocate N toward the shoot maximizing photosynthesis/carbon fixation as a primary adaptive strategy to N limitation.

  8. Foxtail Millet [Setaria italica (L.) Beauv.] Grown under Low Nitrogen Shows a Smaller Root System, Enhanced Biomass Accumulation, and Nitrate Transporter Expression.

    Science.gov (United States)

    Nadeem, Faisal; Ahmad, Zeeshan; Wang, Ruifeng; Han, Jienan; Shen, Qi; Chang, Feiran; Diao, Xianmin; Zhang, Fusuo; Li, Xuexian

    2018-01-01

    Foxtail millet (FM) [ Setaria italica (L.) Beauv.] is a grain and forage crop well adapted to nutrient-poor soils. To date little is known how FM adapts to low nitrogen (LN) at the morphological, physiological, and molecular levels. Using the FM variety Yugu1, we found that LN led to lower chlorophyll contents and N concentrations, and higher root/shoot and C/N ratios and N utilization efficiencies under hydroponic culture. Importantly, enhanced biomass accumulation in the root under LN was in contrast to a smaller root system, as indicated by significant decreases in total root length; crown root number and length; and lateral root number, length, and density. Enhanced carbon allocation toward the root was rather for significant increases in average diameter of the LN root, potentially favorable for wider xylem vessels or other anatomical alterations facilitating nutrient transport. Lower levels of IAA and CKs were consistent with a smaller root system and higher levels of GA may promote root thickening under LN. Further, up-regulation of SiNRT1.1, SiNRT2.1, and SiNAR2.1 expression and nitrate influx in the root and that of SiNRT1.11 and SiNRT1.12 expression in the shoot probably favored nitrate uptake and remobilization as a whole. Lastly, more soluble proteins accumulated in the N-deficient root likely as a result of increases of N utilization efficiencies. Such "excessive" protein-N was possibly available for shoot delivery. Thus, FM may preferentially transport carbon toward the root facilitating root thickening/nutrient transport and allocate N toward the shoot maximizing photosynthesis/carbon fixation as a primary adaptive strategy to N limitation.

  9. Root phenotypic differences across a historical gradient of wheat genotypes alter soil rhizosphere communities and their impact on nitrogen cycling

    Science.gov (United States)

    Kallenbach, C.; Junaidi, D.; Fonte, S.; Byrne, P. F.; Wallenstein, M. D.

    2017-12-01

    Plants and soil microorganisms can exhibit coevolutionary relationships where, for example, in exchange for root carbon, rhizosphere microbes enhance plant fitness through improved plant nutrient availability. Organic agriculture relies heavily on these interactions to enhance crop nitrogen (N) availability. However, modern agriculture and breeding under high mineral N fertilization may have disrupted these interactions through alterations to belowground carbon inputs and associated impacts on the soil microbiome. As sustainability initiatives lead to a restoration of agricultural soil organic matter, modern crop cultivars may still be constrained by crop roots' ability to effectively support microbial-mediated N mineralization. We investigated how differences in root traits across a historical gradient of spring wheat genotypes influence the rhizosphere microbial community and effects on soil N and wheat yield. Five genotypes, representing wild (Wild), pre-Green Revolution (Old), and modern (Modern) wheat, were grown under greenhouse conditions in soils with and without compost to also compare genotype response to difference in native soil microbiomes and organic resource availability. We analyzed rhizosphere soils for microbial community composition, enzyme activities, inorganic N, and microbial biomass. Root length density, surface area, fine root volume and root:shoot ratio were higher in the Wild and Old genotype (Gypsum) compared to the two Modern genotypes (Psoil inorganic N, compared to Modern genotypes. However, under unamended soils, the microbial community and soil N were not affected by genotypes. We also relate how root traits and N cycling across genotypes correspond to microbial community composition. Our preliminary data suggest that the older wheat genotypes and their root traits are more effective at enhancing microbial N mineralization under organically managed soils. Thus, to optimize crop N availability from organic sources, breeding efforts

  10. Characterizing root system characteristics with Electrical resistivity Tomography: a virtual rhizotron simulation

    Science.gov (United States)

    Rao, Sathyanarayan; Ehosioke, Solomon; Lesparre, Nolwenn; Nguyen, Frédéric; Javaux, Mathieu

    2017-04-01

    Electrical Resistivity Tomography (ERT) is more and more used for monitoring soil water content in a cropped soil. Yet, the impact of roots on the signal is often neglected and a topic of controversy. In several studies related to soil-root system, it has been showed that the measured root mass density statistically correlates with the electrical conductivity (EC) data obtained from ERT. In addition, some studies suggest that some roots are more electrically conductive than soil for most water content. Thus, higher EC of roots suggest that it might have a measurable impact on ERT signals. In this work, virtual rhizotrons are simulated using the software package called R-SWMS that solves water and solute transport in plant root-soil system, including root growth. The distribution of water content obtained from R-SWMS simulation is converted into EC data using pedo-physical models. The electrical properties of roots and rhizosphere are explicitly included in the EC data to form a conductivity map (CM) with a very detailed spatial resolution. Forward ERT simulations is then carried out for CM generated for various root architectures and soil conditions to study the impact of roots on ERT forward (current and voltage patterns) and inverse solutions. It is demonstrated that under typical injection schemes with lateral electrodes, root system is hardly measurable. However, it is showed that adding electrodes and constraints on the ERT inversion based on root architecture help quantifying root system mass and extent.

  11. Statistical modeling of nitrogen-dependent modulation of root system architecture in Arabidopsis thaliana.

    Science.gov (United States)

    Araya, Takao; Kubo, Takuya; von Wirén, Nicolaus; Takahashi, Hideki

    2016-03-01

    Plant root development is strongly affected by nutrient availability. Despite the importance of structure and function of roots in nutrient acquisition, statistical modeling approaches to evaluate dynamic and temporal modulations of root system architecture in response to nutrient availability have remained as widely open and exploratory areas in root biology. In this study, we developed a statistical modeling approach to investigate modulations of root system architecture in response to nitrogen availability. Mathematical models were designed for quantitative assessment of root growth and root branching phenotypes and their dynamic relationships based on hierarchical configuration of primary and lateral roots formulating the fishbone-shaped root system architecture in Arabidopsis thaliana. Time-series datasets reporting dynamic changes in root developmental traits on different nitrate or ammonium concentrations were generated for statistical analyses. Regression analyses unraveled key parameters associated with: (i) inhibition of primary root growth under nitrogen limitation or on ammonium; (ii) rapid progression of lateral root emergence in response to ammonium; and (iii) inhibition of lateral root elongation in the presence of excess nitrate or ammonium. This study provides a statistical framework for interpreting dynamic modulation of root system architecture, supported by meta-analysis of datasets displaying morphological responses of roots to diverse nitrogen supplies. © 2015 Institute of Botany, Chinese Academy of Sciences.

  12. Symmetries of the octonionic root system of E8

    International Nuclear Information System (INIS)

    Koca, M.

    1990-09-01

    Octonionic root system of E 8 is decomposed as the 9 sets of Hurwitz integers, each set satisfying the binary tetrahedral group structure, and the 12 sets of quaternionic units, each set obeying the dicyclic group structure of order 12. This fact is used to prove that the automorphism group of the octonionic root system of E 7 is the finite subgroup of G 2 , of order 12096; an explicit 7 x 7 matrix realization of which is constructed. Possible use of the octonionic representation of the E 6 root system as orbifolds and the relevance of the binary tetrahedral structures with the statistical mechanics models are suggested. (author). 16 refs, 6 figs

  13. Genetic analysis of the gravitropic set-point angle in lateral roots of arabidopsis

    Science.gov (United States)

    Mullen, J. L.; Hangarter, R. P.

    2003-05-01

    Research on gravity responses in plants has mostly focused on primary roots and shoots, which typically orient to a vertical orientation. However, the distribution of lateral organs and their characteristically non-vertical growth orientation are critical for the determination of plant form. For example, in Arabidopsis, when lateral roots emerge from the primary root, they grow at a nearly horizontal orientation. As they elongate, the roots slowly curve until they eventually reach a vertical orientation. The regulation of this lateral root orientation is an important component affecting overall root system architecture. We found that this change in orientation is not simply due to the onset of gravitropic competence, as non-vertical lateral roots are capable of both positive and negative gravitropism. Thus, the horizontal growth of new lateral roots appears to be determined by what is called the gravitropic set-point angle (GSA). This developmental control of the GSA of lateral roots in Arabidopsis provides a useful system for investigating the components involved in regulating gravitropic responses. Using this system, we have identified several Arabidopsis mutants that have altered lateral root orientations but maintain normal primary root orientation.

  14. Changes in root cap pH are required for the gravity response of the Arabidopsis root

    Science.gov (United States)

    Fasano, J. M.; Swanson, S. J.; Blancaflor, E. B.; Dowd, P. E.; Kao, T. H.; Gilroy, S.

    2001-01-01

    Although the columella cells of the root cap have been identified as the site of gravity perception, the cellular events that mediate gravity signaling remain poorly understood. To determine if cytoplasmic and/or wall pH mediates the initial stages of root gravitropism, we combined a novel cell wall pH sensor (a cellulose binding domain peptide-Oregon green conjugate) and a cytoplasmic pH sensor (plants expressing pH-sensitive green fluorescent protein) to monitor pH dynamics throughout the graviresponding Arabidopsis root. The root cap apoplast acidified from pH 5.5 to 4.5 within 2 min of gravistimulation. Concomitantly, cytoplasmic pH increased in columella cells from 7.2 to 7.6 but was unchanged elsewhere in the root. These changes in cap pH preceded detectable tropic growth or growth-related pH changes in the elongation zone cell wall by 10 min. Altering the gravity-related columella cytoplasmic pH shift with caged protons delayed the gravitropic response. Together, these results suggest that alterations in root cap pH likely are involved in the initial events that mediate root gravity perception or signal transduction.

  15. Estimation of runoff mitigation by morphologically different cover crop root systems

    Science.gov (United States)

    Yu, Yang; Loiskandl, Willibald; Kaul, Hans-Peter; Himmelbauer, Margarita; Wei, Wei; Chen, Liding; Bodner, Gernot

    2016-07-01

    Hydrology is a major driver of biogeochemical processes underlying the distinct productivity of different biomes, including agricultural plantations. Understanding factors governing water fluxes in soil is therefore a key target for hydrological management. Our aim was to investigate changes in soil hydraulic conductivity driven by morphologically different root systems of cover crops and their impact on surface runoff. Root systems of twelve cover crop species were characterized and the corresponding hydraulic conductivity was measured by tension infiltrometry. Relations of root traits to Gardner's hydraulic conductivity function were determined and the impact on surface runoff was estimated using HYDRUS 2D. The species differed in both rooting density and root axes thickness, with legumes distinguished by coarser axes. Soil hydraulic conductivity was changed particularly in the plant row where roots are concentrated. Specific root length and median root radius were the best predictors for hydraulic conductivity changes. For an intensive rainfall simulation scenario up to 17% less rainfall was lost by surface runoff in case of the coarsely rooted legumes Melilotus officinalis and Lathyrus sativus, and the densely rooted Linum usitatissimum. Cover crops with coarse root axes and high rooting density enhance soil hydraulic conductivity and effectively reduce surface runoff. An appropriate functional root description can contribute to targeted cover crop selection for efficient runoff mitigation.

  16. Ambient ultraviolet radiation in the Arctic reduces root biomass and alters microbial community composition but has no effects on microbial biomass

    DEFF Research Database (Denmark)

    Rinnan, R.; Keinänen, M.M.; Kasurinen, A.

    2005-01-01

    We assessed the effects of ambient solar ultraviolet (UV) radiation on below-ground parameters in an arctic heath in north-eastern Greenland. We hypothesized that the current UV fluxes would reduce root biomass and mycorrhizal colonization and that these changes would lead to lower soil microbial...... biomass and altered microbial community composition. These hypotheses were tested on cored soil samples from a UV reduction experiment with three filter treatments (Mylar, 60% UV-B reduction; Lexan, up to 90% UV-B reduction+UV-A reduction; UV transparent Teflon, filter control) and an open control...... treatment in two study sites after 3 years' manipulation. Reduction of both UV-A and UV-B radiation caused over 30% increase in the root biomass of Vaccinium uliginosum, which was the dominant plant species. UV reduction had contrasting effects on ericoid mycorrhizal colonization of V. uliginosum roots...

  17. Colonization of Plant Growth Promoting Rhizobacteria (PGPR) on Two Different Root Systems

    International Nuclear Information System (INIS)

    Chaudhry, M. Z.; Naz, A. U.; Nawaz, A.; Nawaz, A.; Mukhtar, H.

    2016-01-01

    Phytohormones producing bacteria enhance the plants growth by positively affecting growth of the root. Plant growth promoting bacteria (PGPR) must colonize the plant roots to contribute to the plant's endogenous pool of phytohormones. Colonization of these plant growth promoting rhizobacteria isolated from rhizosplane and soil of different crops was evaluated on different root types to establish if the mechanism of host specificity exist. The bacteria were isolated from maize, wheat, rice, canola and cotton and phytohormone production was detected and quantified by HPLC. Bacteria were inoculated on surface sterilized seeds of different crops and seeds were germinated. After 7 days the bacteria were re-isolated from the roots and the effect of these bacteria was observed by measuring increase in root length. Bacteria isolated from one plant family (monocots) having fibrous root performed well on similar root system and failed to give significant results on other roots (tap root) of dicots. Some aggressive strains were able to colonize both root systems. The plant growth promoting activities of the bacteria were optimum on the same plant from whom roots they were isolated. The results suggest that bacteria adapt to the root they naturally inhabit and colonize the same plant root systems preferably. Although the observe trend indicate host specificity but some bacteria were aggressive colonizers which grew on all the plants used in experiment. (author)

  18. Phenotyping Root System Architecture of Cotton (Gossypium barbadense L. Grown Under Salinity

    Directory of Open Access Journals (Sweden)

    Mottaleb Shady A.

    2017-12-01

    Full Text Available Soil salinity causes an annual deep negative impact to the global agricultural economy. In this study, the effects of salinity on early seedling physiology of two Egyptian cotton (Gossypium barbadense L. cultivars differing in their salinity tolerance were examined. Also the potential use of a low cost mini-rhizotron system to measure variation in root system architecture (RSA traits existing in both cultivars was assessed. Salt tolerant cotton cultivar ‘Giza 90’ produced significantly higher root and shoot biomass, accumulated lower Na+/K+ ratio through a higher Na+ exclusion from both roots and leaves as well as synthesized higher proline contents compared to salt sensitive ‘Giza 45’ cultivar. Measuring RSA in mini-rhizotrons containing solid MS nutrient medium as substrate proved to be more precise and efficient than peat moss/sand mixture. We report superior values of main root growth rate, total root system size, main root length, higher number of lateral roots and average lateral root length in ‘Giza 90’ under salinity. Higher lateral root density and length together with higher root tissue tolerance of Na+ ions in ‘Giza 90’ give it an advantage to be used as donor genotype for desirable root traits to other elite cultivars.

  19. The effect of root temperature on the uptake and metabolism of anions by the root system of Zea mays L. I

    International Nuclear Information System (INIS)

    Holobrada, M.; Mistrik, I.; Kolek, J.

    1980-01-01

    The effect of root temperature upon the uptake of 35 S-sulfate by intact 21 days old maize roots was discussed. The plant roots grown at 20 degC were cooled in steps down to 15 degC or 5 degC. The rate of 35 S uptake was studied both in the whole root system and separately in the individual roots (primary seminal root, seminal adventitious roots and nodal roots). Differences were ascertained at lower uptakes by various root samples from resistant and nonresistant maize cultivars. (author)

  20. A complete system for 3D reconstruction of roots for phenotypic analysis.

    Science.gov (United States)

    Kumar, Pankaj; Cai, Jinhai; Miklavcic, Stanley J

    2015-01-01

    Here we present a complete system for 3D reconstruction of roots grown in a transparent gel medium or washed and suspended in water. The system is capable of being fully automated as it is self calibrating. The system starts with detection of root tips in root images from an image sequence generated by a turntable motion. Root tips are detected using the statistics of Zernike moments on image patches centred on high curvature points on root boundary and Bayes classification rule. The detected root tips are tracked in the image sequence using a multi-target tracking algorithm. Conics are fitted to the root tip trajectories using a novel ellipse fitting algorithm which weighs the data points by its eccentricity. The conics projected from the circular trajectory have a complex conjugate intersection which are image of the circular points. Circular points constraint the image of the absolute conics which are directly related to the internal parameters of the camera. The pose of the camera is computed from the image of the rotation axis and the horizon. The silhouettes of the roots and camera parameters are used to reconstruction the 3D voxel model of the roots. We show the results of real 3D reconstruction of roots which are detailed and realistic for phenotypic analysis.

  1. On Split Lie Algebras with Symmetric Root Systems

    Indian Academy of Sciences (India)

    ... and any I j a well described ideal of , satisfying [ I j , I k ] = 0 if j ≠ k . Under certain conditions, the simplicity of is characterized and it is shown that is the direct sum of the family of its minimal ideals, each one being a simple split Lie algebra with a symmetric root system and having all its nonzero roots connected.

  2. On split Lie algebras with symmetric root systems

    Indian Academy of Sciences (India)

    ideal of L, satisfying [Ij ,Ik] = 0 if j = k. Under certain conditions, the simplicity of L is characterized and it is shown that L is the direct sum of the family of its minimal ideals, each one being a simple split Lie algebra with a symmetric root system and having all its nonzero roots connected. Keywords. Infinite dimensional Lie ...

  3. Efflux of inorganic substances from young barley roots. II. Movement in roots and efflux of sodium in plants with divided root systems

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, H; Kojima, S [Radiation Center of Osaka Prefecture, Sakai (Japan)

    1977-09-01

    The root system of young barley was almost halved, and the two portions were planted in culture grounds with different composition after severing the capillary connection between both root groups. With one portion in the acid medium solution of various compositions and the other in the /sup 22/Na-absorbing medium solution, the sodium absorbed from one root group moved to and flowed out from the other root group, and this state was observed. Also, the efflux of potassium from the root was observed. (1) The Na efflux was small in the culture ground with dilute hydrochloric acid, and larger in that with AlCl/sub 3/ or phosphate. (2) The K efflux was large under short-day condition. (3) Under short-day condition, in the culture ground with soluble Al, the K efflux was promoted by nitrogen-source addition, but the Na efflux was suppressed.

  4. Research on the Strength Variation of Root-Clay Systems under Freeze-Thaw Action

    Directory of Open Access Journals (Sweden)

    Lin Yang

    2017-01-01

    Full Text Available The aim of this paper is to study the influence of an effective root system of rhizome plants on the reinforcement of slope soil under freeze-thaw conditions. This study focused on the mechanical properties between roots and clay in the root system of four plant species from different regions of China (northeast, northern, central, and southern areas: Setaria viridis, Eleusine indica, Zoysia japonica, and Carex leucochlora. Based on the interfacial friction effects between the plant roots and the soil, pull-out tests and unconfined compressive strength tests were conducted on the reinforced soil system for varying numbers of freeze-thaw cycles. Several stages of the pull-out process of the root system in clay are explicitly proposed based on the interfacial friction test results. The results showed that the friction effect between Zoysia japonica roots and the soil was the most significant and that these roots had the best reinforcement effect. In contrast, the friction and reinforcement effects between Setaria viridis roots and the soil were the worst, and the resulting unconfined compressive strength was the smallest. However, the freeze-thaw resistance ability of the Setaria viridis and soil system was stronger than that of the Zoysia japonica system.

  5. Quantum systems related to root systems and radial parts of Laplace operators

    OpenAIRE

    Olshanetsky, M. A.; Perelomov, A. M.

    2002-01-01

    The relation between quantum systems associated to root systems and radial parts of Laplace operators on symmetric spaces is established. From this it follows the complete integrability of some quantum systems.

  6. TGeoCad: an Interface between ROOT and CAD Systems

    International Nuclear Information System (INIS)

    Luzzi, C; Carminati, F

    2014-01-01

    In the simulation of High Energy Physics experiment a very high precision in the description of the detector geometry is essential to achieve the required performances. The physicists in charge of Monte Carlo Simulation of the detector need to collaborate efficiently with the engineers working at the mechanical design of the detector. Often, this collaboration is made hard by the usage of different and incompatible software. ROOT is an object-oriented C++ framework used by physicists for storing, analyzing and simulating data produced by the high-energy physics experiments while CAD (Computer-Aided Design) software is used for mechanical design in the engineering field. The necessity to improve the level of communication between physicists and engineers led to the implementation of an interface between the ROOT geometrical modeler used by the virtual Monte Carlo simulation software and the CAD systems. In this paper we describe the design and implementation of the TGeoCad Interface that has been developed to enable the use of ROOT geometrical models in several CAD systems. To achieve this goal, the ROOT geometry description is converted into STEP file format (ISO 10303), which can be imported and used by many CAD systems

  7. TGeoCad: an Interface between ROOT and CAD Systems

    Science.gov (United States)

    Luzzi, C.; Carminati, F.

    2014-06-01

    In the simulation of High Energy Physics experiment a very high precision in the description of the detector geometry is essential to achieve the required performances. The physicists in charge of Monte Carlo Simulation of the detector need to collaborate efficiently with the engineers working at the mechanical design of the detector. Often, this collaboration is made hard by the usage of different and incompatible software. ROOT is an object-oriented C++ framework used by physicists for storing, analyzing and simulating data produced by the high-energy physics experiments while CAD (Computer-Aided Design) software is used for mechanical design in the engineering field. The necessity to improve the level of communication between physicists and engineers led to the implementation of an interface between the ROOT geometrical modeler used by the virtual Monte Carlo simulation software and the CAD systems. In this paper we describe the design and implementation of the TGeoCad Interface that has been developed to enable the use of ROOT geometrical models in several CAD systems. To achieve this goal, the ROOT geometry description is converted into STEP file format (ISO 10303), which can be imported and used by many CAD systems.

  8. Toward a Low-Cost System for High-Throughput Image-Based Phenotyping of Root System Architecture

    Science.gov (United States)

    Davis, T. W.; Schneider, D. J.; Cheng, H.; Shaw, N.; Kochian, L. V.; Shaff, J. E.

    2015-12-01

    Root system architecture is being studied more closely for improved nutrient acquisition, stress tolerance and carbon sequestration by relating the genetic material that corresponds to preferential physical features. This information can help direct plant breeders in addressing the growing concerns regarding the global demand on crops and fossil fuels. To help support this incentive comes a need to make high-throughput image-based phenotyping of plant roots, at the individual plant scale, simpler and more affordable. Our goal is to create an affordable and portable product for simple image collection, processing and management that will extend root phenotyping to institutions with limited funding (e.g., in developing countries). Thus, a new integrated system has been developed using the Raspberry Pi single-board computer. Similar to other 3D-based imaging platforms, the system utilizes a stationary camera to photograph a rotating crop root system (e.g., rice, maize or sorghum) that is suspended either in a gel or on a mesh (for hydroponics). In contrast, the new design takes advantage of powerful open-source hardware and software to reduce the system costs, simplify the imaging process, and manage the large datasets produced by the high-resolution photographs. A newly designed graphical user interface (GUI) unifies the system controls (e.g., adjusting camera and motor settings and orchestrating the motor motion with image capture), making it easier to accommodate a variety of experiments. During each imaging session, integral metadata necessary for reproducing experiment results are collected (e.g., plant type and age, growing conditions and treatments, camera settings) using hierarchical data format files. These metadata are searchable within the GUI and can be selected and extracted for further analysis. The GUI also supports an image previewer that performs limited image processing (e.g., thresholding and cropping). Root skeletonization, 3D reconstruction and

  9. Understanding alfalfa root systems and their rold in abiotic stress tolerance

    Science.gov (United States)

    The root system architecture (RSA) impacts the capacity of the plant for efficient water and nutrient uptake. Root phenes have been associated with productivity under stress conditions and persistence of perennial species. The objectives of this study were to identify root traits that increase produ...

  10. Roots Withstanding their Environment: Exploiting Root System Architecture Responses to Abiotic Stress to Improve Crop Tolerance

    Science.gov (United States)

    Koevoets, Iko T.; Venema, Jan Henk; Elzenga, J. Theo. M.; Testerink, Christa

    2016-01-01

    To face future challenges in crop production dictated by global climate changes, breeders and plant researchers collaborate to develop productive crops that are able to withstand a wide range of biotic and abiotic stresses. However, crop selection is often focused on shoot performance alone, as observation of root properties is more complex and asks for artificial and extensive phenotyping platforms. In addition, most root research focuses on development, while a direct link to the functionality of plasticity in root development for tolerance is often lacking. In this paper we review the currently known root system architecture (RSA) responses in Arabidopsis and a number of crop species to a range of abiotic stresses, including nutrient limitation, drought, salinity, flooding, and extreme temperatures. For each of these stresses, the key molecular and cellular mechanisms underlying the RSA response are highlighted. To explore the relevance for crop selection, we especially review and discuss studies linking root architectural responses to stress tolerance. This will provide a first step toward understanding the relevance of adaptive root development for a plant’s response to its environment. We suggest that functional evidence on the role of root plasticity will support breeders in their efforts to include root properties in their current selection pipeline for abiotic stress tolerance, aimed to improve the robustness of crops. PMID:27630659

  11. The Ca2+ pump inhibitor, thapsigargin, inhibits root gravitropism in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    DANIELA C URBINA

    2006-01-01

    Full Text Available Thapsigargin, a specific inhibitor of most animal intracellular SERCA-type Ca2+ pumps present in the sarcoplasmic/endoplasmic reticulum, was originally isolated from the roots of the Mediterranean plant Thapsia gargancia L. Here, we demonstrate that this root-derived compound is capable of altering root gravitropism in Arabidopsis thaliana. Thapsigargin concentrations as low as 0.1 µM alter root gravitropism whereas under similar conditions cyclopiazonic acid does not. Furthermore, a fluorescently conjugated thapsigargin (BODIPY FL thapsigargin suggests that target sites for thapsigargin are located in intracellular organelles in the root distal elongation zone and the root cap, regions known to regulate root gravitropism

  12. Fluidity of pea root plasma membranes under altered gravity

    Science.gov (United States)

    Klymchuk, D. O.; Baranenko, V. V.; Vorobyova, T. V.; Dubovoy, V. D.

    This investigation aims to determine whether clinorotation 2 rev min of pea Pisum sativum L seedlings induces the alterations in the physical-chemical properties of cellular membranes including the plasma membrane fluidity The last is an important regulator of functional activity of membrane enzymes The plasma membranes were isolated by aqueous two-phase partitioning from roots of 6-day old pea seedlings The membrane fluidity was examined by fluorescence spectroscopy using pyrene probe The plasma membrane vesicles with known protein concentration were added to the incubation buffer to a final concentration of 50 mu g of protein per ml A small amount by 1 mu l of pyrene solution in 2-propanol was added to the incubation mixture to a final probe concentration 5 mu M at constant mixing Fluorescence spectra were measured using a Perkin-Elmer LS-50 spectrofluorometer Perkin-Elmer England Pyrene was excited at 337 nm and fluorescence intensity of monomers I M and excimers I E were measured at 393 and 470 nm respectively The I E I M ratios were 0 081 pm 0 003 and 0 072 pm 0 004 in preparations obtained from clinorotated and the control seedlings respectively This fact indicates that rotation on the clinostat increases the membrane fluidity Compared with controls clinorotated seedlings have also showed a reduced growth and a higher level of total unsaturated fatty acids determined by gas chromatography The factors that influence on the fluidity of membrane lipids in bilayer appear to be the

  13. Avoiding transport bottlenecks in an expanding root system: xylem vessel development in fibrous and pioneer roots under field conditions.

    Science.gov (United States)

    Bagniewska-Zadworna, Agnieszka; Byczyk, Julia; Eissenstat, David M; Oleksyn, Jacek; Zadworny, Marcin

    2012-09-01

    Root systems develop to effectively absorb water and nutrients and to rapidly transport these materials to the transpiring shoot. In woody plants, roots can be born with different functions: fibrous roots are primarily used for water and nutrient absorption, whereas pioneer roots have a greater role in transport. Because pioneer roots extend rapidly in the soil and typically quickly produce fibrous roots, they need to develop transport capacity rapidly so as to avoid becoming a bottleneck to the absorbed water of the developing fibrous roots and, as we hypothesized, immediately activate a specific type of autophagy at a precise time of their development. Using microscopy techniques, we monitored xylem development in Populus trichocarpa roots in the first 7 d after emergence under field conditions. Newly formed pioneer roots contained more primary xylem poles and had larger diameter tracheary elements than fibrous roots. While xylogenesis started later in pioneer roots than in fibrous, it was completed at the same time, resulting in functional vessels on the third to fourth day following root emergence. Programmed cell death was responsible for creating the water conducting capacity of xylem. Although the early xylogenesis processes were similar in fibrous and pioneer roots, secondary vascular development proceeded much more rapidly in pioneer roots. Compared to fibrous roots, rapid development of transport capacity in pioneer roots is not primarily caused by accelerated xylogenesis but by larger and more numerous tracheary elements and by rapid initiation of secondary growth.

  14. Cerium oxide nanoparticles alter the salt stress tolerance of Brassica napus L. by modifying the formation of root apoplastic barriers.

    Science.gov (United States)

    Rossi, Lorenzo; Zhang, Weilan; Ma, Xingmao

    2017-10-01

    Rapidly growing global population adds significant strains on the fresh water resources. Consequently, saline water is increasingly tapped for crop irrigation. Meanwhile, rapid advancement of nanotechnology is introducing more and more engineered nanoparticles into the environment and in agricultural soils. While some negative effects of ENPs on plant health at very high concentrations have been reported, more beneficial effects of ENPs at relatively low concentrations are increasingly noticed, opening doors for potential applications of nanotechnology in agriculture. In particular, we found that cerium oxide nanoparticles (CeO 2 NPs) improved plant photosynthesis in salt stressed plants. Due to the close connections between salt stress tolerance and the root anatomical structures, we postulated that CeO 2 NPs could modify plant root anatomy and improve plant salt stress tolerance. This study aimed at testing the hypothesis with Brassica napus in the presence of CeO 2 NPs (0, 500 mg kg -1 dry sand) and/or NaCl (0, 50 mM) in a growth chamber. Free hand sections of fresh roots were taken every seven days for three weeks and the suberin lamellae development was examined under a fluorescence microscope. The results confirmed the hypothesis that CeO 2 NPs modified the formation of the apoplastic barriers in Brassica roots. In salt stressed plants, CeO 2 NPs shortened the root apoplastic barriers which allowed more Na + transport to shoots and less accumulation of Na + in plant roots. The altered Na + fluxes and transport led to better physiological performance of Brassica and may lead to new applications of nanotechnology in agriculture. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Improving crop nutrient efficiency through root architecture modifications.

    Science.gov (United States)

    Li, Xinxin; Zeng, Rensen; Liao, Hong

    2016-03-01

    Improving crop nutrient efficiency becomes an essential consideration for environmentally friendly and sustainable agriculture. Plant growth and development is dependent on 17 essential nutrient elements, among them, nitrogen (N) and phosphorus (P) are the two most important mineral nutrients. Hence it is not surprising that low N and/or low P availability in soils severely constrains crop growth and productivity, and thereby have become high priority targets for improving nutrient efficiency in crops. Root exploration largely determines the ability of plants to acquire mineral nutrients from soils. Therefore, root architecture, the 3-dimensional configuration of the plant's root system in the soil, is of great importance for improving crop nutrient efficiency. Furthermore, the symbiotic associations between host plants and arbuscular mycorrhiza fungi/rhizobial bacteria, are additional important strategies to enhance nutrient acquisition. In this review, we summarize the recent advances in the current understanding of crop species control of root architecture alterations in response to nutrient availability and root/microbe symbioses, through gene or QTL regulation, which results in enhanced nutrient acquisition. © 2015 Institute of Botany, Chinese Academy of Sciences.

  16. Comparison of the root canal debridement ability of two single file systems with a conventional multiple rotary system in long oval-shaped root canals: In vitro study.

    Science.gov (United States)

    Khoshbin, Elham; Shokri, Abbas; Donyavi, Zakieh; Shahriari, Shahriar; Salehimehr, Golsa; Farhadian, Maryam; Kavandi, Zeinab

    2017-08-01

    This study sought to compare the root canal debridement ability of Neolix, Reciproc and ProTaper rotary systems in long oval-shaped root canals. Eighty five extracted single-rooted human teeth with long oval-shaped single root canals were selected and divided into three experimental groups(n=25) and one control group (n= 10). Root canals were filled with Vitapex radiopaque contrast medium and prepared with Neolix, Reciproc or ProTaper systems. The control group only received irrigation. Digital radiographs were obtained at baseline and postoperatively and subjected to digital subtraction. The percentage of reduction in contrast medium was quantified at 0-5 mm and 5-10 mm distances from the apex. The data were analyzed using one-way ANOVA and t-test. The mean percentage of the contrast medium removed was not significantly different in the 0-5mm segment among the three groups ( P =0.6). In the 5-10mm segment a significant difference was found in this regard among the ProTaper and Reciproc groups ( P =0.02) and the highest mean percentage of contrast medium was removed by ProTaper. But, difference between ProTaper and Neolix as well as Neolix and Reciproc was not significant. In Neolix ( P =0.024) and Reciproc ( P =0.002) systems, the mean percentage of the contrast medium removed from the 0-5mm segment was significantly greater than that in 5-10mm segment; however, this difference was not significant in ProTaper group ( P =0.069). Neolix single-file system may be a suitable alternative to ProTaper multiple-file system in debridement of long oval shaped canals. Key words: Root Canal Preparation, Debridement, Root Canal Therapy.

  17. Phosphate-dependent root system architecture responses to salt stress

    KAUST Repository

    Kawa, Dorota; Julkowska, Magdalena; Montero Sommerfeld, Hector; Horst, Anneliek ter; Haring, Michel A; Testerink, Christa

    2016-01-01

    Nutrient availability and salinity of the soil affect growth and development of plant roots. Here, we describe how phosphate availability affects root system architecture (RSA) of Arabidopsis and how phosphate levels modulate responses of the root to salt stress. Phosphate (Pi) starvation reduced main root length and increased the number of lateral roots of Arabidopsis Col-0 seedlings. In combination with salt, low Pi dampened the inhibiting effect of mild salt stress (75mM) on all measured RSA components. At higher NaCl concentrations, the Pi deprivation response prevailed over the salt stress only for lateral root elongation. The Pi deprivation response of lateral roots appeared to be oppositely affected by abscisic acid (ABA) signaling compared to the salt stress response. Natural variation in the response to the combination treatment of salt and Pi starvation within 330 Arabidopsis accessions could be grouped into four response patterns. When exposed to double stress, in general lateral roots prioritized responses to salt, while the effect on main root traits was additive. Interestingly, these patterns were not identical for all accessions studied and multiple strategies to integrate the signals from Pi deprivation and salinity were identified. By Genome Wide Association Mapping (GWAS) 13 genomic loci were identified as putative factors integrating responses to salt stress and Pi starvation. From our experiments, we conclude that Pi starvation interferes with salt responses mainly at the level of lateral roots and that large natural variation exists in the available genetic repertoire of accessions to handle the combination of stresses.

  18. Phosphate-dependent root system architecture responses to salt stress

    KAUST Repository

    Kawa, Dorota

    2016-05-20

    Nutrient availability and salinity of the soil affect growth and development of plant roots. Here, we describe how phosphate availability affects root system architecture (RSA) of Arabidopsis and how phosphate levels modulate responses of the root to salt stress. Phosphate (Pi) starvation reduced main root length and increased the number of lateral roots of Arabidopsis Col-0 seedlings. In combination with salt, low Pi dampened the inhibiting effect of mild salt stress (75mM) on all measured RSA components. At higher NaCl concentrations, the Pi deprivation response prevailed over the salt stress only for lateral root elongation. The Pi deprivation response of lateral roots appeared to be oppositely affected by abscisic acid (ABA) signaling compared to the salt stress response. Natural variation in the response to the combination treatment of salt and Pi starvation within 330 Arabidopsis accessions could be grouped into four response patterns. When exposed to double stress, in general lateral roots prioritized responses to salt, while the effect on main root traits was additive. Interestingly, these patterns were not identical for all accessions studied and multiple strategies to integrate the signals from Pi deprivation and salinity were identified. By Genome Wide Association Mapping (GWAS) 13 genomic loci were identified as putative factors integrating responses to salt stress and Pi starvation. From our experiments, we conclude that Pi starvation interferes with salt responses mainly at the level of lateral roots and that large natural variation exists in the available genetic repertoire of accessions to handle the combination of stresses.

  19. Endodontic implications of the variability of the root canal systems of posterior teeth.

    Science.gov (United States)

    Biggs, J T; Benenati, F W

    1995-01-01

    Variations in the morphology of roots and root canal systems create challenges which the dental practitioner must be able to recognize. Endodontic therapy is predictable and successful only to the extent that the root canal system can be debrided, disinfected and sealed against future contamination. In order to accomplish these goals it is necessary to become familiar with the variability of the system we seek to treat.

  20. Artificial Plant Root System Growth for Distributed Optimization: Models and Emergent Behaviors

    Directory of Open Access Journals (Sweden)

    Su Weixing

    2016-01-01

    Full Text Available Plant root foraging exhibits complex behaviors analogous to those of animals, including the adaptability to continuous changes in soil environments. In this work, we adapt the optimality principles in the study of plant root foraging behavior to create one possible bio-inspired optimization framework for solving complex engineering problems. This provides us with novel models of plant root foraging behavior and with new methods for global optimization. This framework is instantiated as a new search paradigm, which combines the root tip growth, branching, random walk, and death. We perform a comprehensive simulation to demonstrate that the proposed model accurately reflects the characteristics of natural plant root systems. In order to be able to climb the noise-filled gradients of nutrients in soil, the foraging behaviors of root systems are social and cooperative, and analogous to animal foraging behaviors.

  1. Variation of root system characters in collection of semi-dwarf spring barley mutants

    International Nuclear Information System (INIS)

    Nawrot, M.; Zbieszczyk, J.; Maluszynski, M.

    2000-01-01

    The collection of 371 semi-dwarf mutants, derived from 12 spring barley varieties has been used as material for analysis of root system. The mutants have been obtained after mutagenic treatment with N-methyl-N-nitroso urea (MNH), sodium azide (NaN3), gamma-rays and fast neutrons. The following analysis of root system were performed: seminal root growth of 8-day old seedlings, seminal and adventitious root growth of 6-week old plants and dynamics of root growth during first 6 weeks of plant growth. Seminal root length, root number and the length of the first leaf in barley mutants were investigated with the use of paper rollers. Root system analysis of 6-week old plants was performed on genotypes grown in PVC tubes filled with sand, supplemented with 1 mineral salts of MS medium. The following measurements were made: the length of the longest seminal root and the longest adventitious root, the number of adventitious roots and the number of tillers. Analysis of dynamics of root growth during the first six weeks of vegetation was performed at the end of each 7-day growth period in the PVC tubes filled with sand. Great variability in the seminal root length was found in analysed 8-day old seedling population. Almost half of the analysed mutants showed significant root length reduction, but about ten percent of semi-dwarf mutants developed roots with an increased length in comparison to parents. No significant differences were found between analysed mutants and corresponding parent varieties regarding the number of seminal roots. After six weeks of growth, the selected mutants showed differences in the reduction of root length in comparison to the 8-day old seedlings. The results of root growth dynamics indicated that analysed mutants had different patterns in comparison to the parent variety. Differences in the growth dynamics were also observed among the parent varieties. The observed differences in pattern of root growth between mutants and corresponding parents

  2. Root anatomy, morphology, and longevity among root orders in Vaccinium corymbosum (Ericaceae).

    Science.gov (United States)

    Valenzuela-Estrada, Luis R; Vera-Caraballo, Vivianette; Ruth, Leah E; Eissenstat, David M

    2008-12-01

    Understanding root processes at the whole-plant or ecosystem scales requires an accounting of the range of functions within a root system. Studying root traits based on their branching order can be a powerful approach to understanding this complex system. The current study examined the highly branched root system of the ericoid plant, Vaccinium corymbosum L. (highbush blueberry) by classifying its root orders with a modified version of the morphometric approach similar to that used in hydrology for stream classification. Root anatomy provided valuable insight into variation in root function across orders. The more permanent portion of the root system occurred in 4th- and higher-order roots. Roots in these orders had radial growth; the lowest specific root length, N:C ratios, and mycorrhizal colonization; the highest tissue density and vessel number; and the coarsest root diameter. The ephemeral portion of the root system was mainly in the first three root orders. First- and 2nd-order roots were nearly anatomically identical, with similar mycorrhizal colonization and diameter, and also, despite being extremely fine, median lifespans were not very short (115-120 d; estimated with minirhizotrons). Our research underscores the value of examining root traits by root order and its implications to understanding belowground processes.

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

    OpenAIRE

    Kumar Ramesh R.; Reddy Anjaneya Prasanna L.; Subbaiah Chinna J.; Kumar Niranjana A.; Prasad Nagendra H.N.; Bhukya Balakishan

    2011-01-01

    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 ...

  4. Localized Iron Supply Triggers Lateral Root Elongation in Arabidopsis by Altering the AUX1-Mediated Auxin Distribution[C][W][OA

    Science.gov (United States)

    Giehl, Ricardo F.H.; Lima, Joni E.; von Wirén, Nicolaus

    2012-01-01

    Root system architecture depends on nutrient availability, which shapes primary and lateral root development in a nutrient-specific manner. To better understand how nutrient signals are integrated into root developmental programs, we investigated the morphological response of Arabidopsis thaliana roots to iron (Fe). Relative to a homogeneous supply, localized Fe supply in horizontally separated agar plates doubled lateral root length without having a differential effect on lateral root number. In the Fe uptake-defective mutant iron-regulated transporter1 (irt1), lateral root development was severely repressed, but a requirement for IRT1 could be circumvented by Fe application to shoots, indicating that symplastic Fe triggered the local elongation of lateral roots. The Fe-stimulated emergence of lateral root primordia and root cell elongation depended on the rootward auxin stream and was accompanied by a higher activity of the auxin reporter DR5-β-glucuronidase in lateral root apices. A crucial role of the auxin transporter AUXIN RESISTANT1 (AUX1) in Fe-triggered lateral root elongation was indicated by Fe-responsive AUX1 promoter activities in lateral root apices and by the failure of the aux1-T mutant to elongate lateral roots into Fe-enriched agar patches. We conclude that a local symplastic Fe gradient in lateral roots upregulates AUX1 to accumulate auxin in lateral root apices as a prerequisite for lateral root elongation. PMID:22234997

  5. Morphology and biomass variations in root system of young tomato plants (Solanum sp.)

    International Nuclear Information System (INIS)

    Álvarez Gil, Marta A.; Fernández, Ana Fita; Ruiz Sánchez, María del C.; Bolarín Jiménez, María del C.

    2016-01-01

    The scarce exploitation of genotypic variability present in plant roots is an attractive breeding choice with regard to abiotic stresses and supports the objective of this work, which is to identify genotypic variation in root system traits of tomato genotypes (Solanum sp.). Thus, five tomato genotypes were studied: the commercial hybrid cultivar Jaguar (S. lycopersicum), Pera, Volgogradiskij and PE-47 entry (S. pennellii), which were collected in Peru, and the interspecific hybrid PeraxPE-47. Plants were grown in hydroponics for 26 days since germination; their roots were extracted and images were digitalized on scanner to evaluate total length, average diameter, the projected area and root length, following the categories per diameter of the whole root system through software Win Rhizo Pro 2003. The dry mass of roots and aerial parts was also recorded. Results indicated that genotypes differed in morphology, length according to diameter, root system spatial configuration and biomass, mainly with respect to the wild salinity resistant species PE-47. The interspecific hybrid PxPE-47 could be used as a rootstock to increase salt tolerance of susceptible cultivars. (author)

  6. MMS control system analysis using automated root-locus plot generation

    International Nuclear Information System (INIS)

    Hefler, J.W.

    1987-01-01

    Use of the Modular Modeling System (MMS) for control systems improvement has been impeded by the need to plot eigenvalues manually. This problem has been solved by an automatic eigenvalue plotting routine. A practical procedure for control systems analysis based upon automatically generated root-locus plots has been developed using the Advanced Continuous Simulation Language (ACSL)-based version of the Modular Modeling System. Examples are given of typical ACSL run-time statements. Actual root-locus and time history plots are shown for simple models (4 state variables). More complex models are discussed. The plots show the control systems response before and after the determination of tuning parameters using the methods described

  7. Solving polynomial systems using no-root elimination blending schemes

    KAUST Repository

    Barton, Michael

    2011-12-01

    Searching for the roots of (piecewise) polynomial systems of equations is a crucial problem in computer-aided design (CAD), and an efficient solution is in strong demand. Subdivision solvers are frequently used to achieve this goal; however, the subdivision process is expensive, and a vast number of subdivisions is to be expected, especially for higher-dimensional systems. Two blending schemes that efficiently reveal domains that cannot contribute by any root, and therefore significantly reduce the number of subdivisions, are proposed. Using a simple linear blend of functions of the given polynomial system, a function is sought after to be no-root contributing, with all control points of its BernsteinBézier representation of the same sign. If such a function exists, the domain is purged away from the subdivision process. The applicability is demonstrated on several CAD benchmark problems, namely surfacesurfacesurface intersection (SSSI) and surfacecurve intersection (SCI) problems, computation of the Hausdorff distance of two planar curves, or some kinematic-inspired tasks. © 2011 Elsevier Ltd. All rights reserved.

  8. Optical methods for creating delivery systems of chemical compounds to plant roots

    Science.gov (United States)

    Kuznetsov, Pavel E.; Rogacheva, Svetlana M.; Arefeva, Oksana A.; Minin, Dmitryi V.; Tolmachev, Sergey A.; Kupadze, Machammad S.

    2004-08-01

    Spectrophotometric and fluorescence methods have been used for creation and investigation of various systems of target delivery of chemical compounds to roots of plants. The possibility of using liposomes, incrusted by polysaccharides of the external surface of nitrogen-fixing rizospheric bacteria Azospirillum brasilense SP 245, and nanoparticles incrusted by polysaccharides of wheat roots, as the named systems has been shown. The important role of polysaccharide-polysaccharide interaction in the adsorption processes of bacteria on wheat roots has been demonstrated.

  9. Inhibition of primary roots and stimulation of lateral root development in Arabidopsis thaliana by the rhizobacterium Serratia marcescens 90-166 is through both auxin-dependent and -independent signaling pathways.

    Science.gov (United States)

    Shi, Chun-Lin; Park, Hyo-Bee; Lee, Jong Suk; Ryu, Sangryeol; Ryu, Choong-Min

    2010-03-01

    The rhizobacterium Serratia marcescens strain 90-166 was previously reported to promote plant growth and induce resistance in Arabidopsis thaliana. In this study, the influence of strain 90-166 on root development was studied in vitro. We observed inhibition of primary root elongation, enhanced lateral root emergence, and early emergence of second order lateral roots after inoculation with strain 90-166 at a certain distance from the root. Using the DR5::GUS transgenic A. thaliana plant and an auxin transport inhibitor, N-1-naphthylphthalamic acid, the altered root development was still elicited by strain 90-166, indicating that this was not a result of changes in plant auxin levels. Intriguingly, indole-3-acetic acid, a major auxin chemical, was only identified just above the detection limit in liquid culture of strain 90-166 using liquid chromatography-mass spectrometry. Focusing on bacterial determinants of the root alterations, we found that primary root elongation was inhibited in seedlings treated with cell supernatant (secreted compounds), while lateral root formation was induced in seedlings treated with lysate supernatant (intracellular compounds). Further study revealed that the alteration of root development elicited by strain 90-166 involved the jasmonate, ethylene, and salicylic acid signaling pathways. Collectively, our results suggest that strain 90-166 can contribute to plant root development via multiple signaling pathways.

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

    Science.gov (United States)

    Danjon, Frédéric; Caplan, Joshua S; Fortin, Mathieu; Meredieu, Céline

    2013-01-01

    Root systems of woody plants generally display a strong relationship between the cross-sectional area 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 a 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 years) from a stand in southwest France. 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.

  11. Establishment of a transgenic hairy root system in wild and domesticated watermelon (Citrullus lanatus) for studying root vigor under drought.

    Science.gov (United States)

    Kajikawa, Masataka; Morikawa, Kaoru; Abe, Yosuke; Yokota, Akiho; Akashi, Kinya

    2010-07-01

    Root vigor is an important trait for the growth of terrestrial plants, especially in water-deficit environments. Although deserts plants are known for their highly developed root architecture, the molecular mechanism responsible for this trait has not been determined. Here we established an efficient protocol for the genetic manipulation of two varieties of watermelon plants: a desert-grown wild watermelon that shows vigorous root growth under drought, and a domesticated cultivar showing retardation of root growth under drought stress. Agrobacterium rhizogenes-mediated transgenic hairy roots were efficiently induced and selected from the hypocotyls of these plants. Transgenic GUS expression was detected in the roots by RT-PCR and histochemical GUS staining. Moreover, a liquid culture system for evaluating their root growth was also established. Interestingly, growth of the hairy roots derived from domesticated variety of watermelon strongly inhibited under high osmotic condition, whereas the hairy roots derived from wild variety of watermelon retained substantial growth rates under the stress condition. The new protocol presented here offers a powerful tool for the comparative study of the molecular mechanism underlying drought-induced root growth in desert plants.

  12. Comparison of Alterations in the Surface Topographies of HyFlex CM and HyFlex EDM Nickel-titanium Files after Root Canal Preparation: A Three-dimensional Optical Profilometry Study.

    Science.gov (United States)

    Uslu, Gülşah; Özyürek, Taha; Yılmaz, Koray

    2018-01-01

    The aims of the present study were to examine the surface topographies of intact HyFlex CM and HyFlex EDM nickel-titanium files and to compare alterations in the surface topographies of these files after root canal preparation of severely curved canals of molar teeth. Eight HyFlex CM (25/.08) and 8 HyFlex EDM (25/.08) files were included in the present study. In total, 64 severely curved canals of molar teeth, with curvature angles ranging between 50° and 70°, were prepared with HyFlex CM and EDM (n = 32 in each group). Quantitative and qualitative analyses of the files' surface deformation were performed by using three-dimensional optical profilometry before and after root canal preparation. The data were analyzed with the Student t test at the 5% significant level by using SPSS 21.0 software. In the HyFlex EDM group, the qualitative evaluation revealed the presence of cracks and microcavities after use of the file for root canal preparation, whereas only minor surface deformation was observed in the HyFlex CM group. The average roughness, root mean square roughness, and peak to valley height values of the HyFlex EDM group were significantly higher than those of the HyFlex CM group before and after root canal preparation (P EDM group was not statistically significant (P > .5). Within the limitations of the present study, the HyFlex CM files showed significantly higher surface alterations compared with the HyFlex EDM files after the preparation of severely curved root canals. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  13. Treeline advances and associated shifts in the ground vegetation alter fine root dynamics and mycelia production in the South and Polar Urals.

    Science.gov (United States)

    Solly, Emily F; Djukic, Ika; Moiseev, Pavel A; Andreyashkina, Nelly I; Devi, Nadezhda M; Göransson, Hans; Mazepa, Valeriy S; Shiyatov, Stepan G; Trubina, Marina R; Schweingruber, Fritz H; Wilmking, Martin; Hagedorn, Frank

    2017-02-01

    Climate warming is shifting the elevational boundary between forests and tundra upwards, but the related belowground responses are poorly understood. In the pristine South and Polar Urals with shifts of the treeline ecotone documented by historical photographs, we investigated fine root dynamics and production of extramatrical mycorrhizal mycelia (EMM) along four elevational transects reaching from the closed forest to the treeless tundra. In addition, we analysed elevational differences in climate and vegetation structure, and excavated trees to estimate related changes in the partitioning between below- and aboveground biomass. Fine root biomass of trees (<2 mm) increased by 13-79% with elevation, paralleled by a 35-72% increase in ground vegetation fine roots from the closed forest to the tundra. During the first year of decomposition, mass loss of fine root litter from different vegetation types was greater at lower elevations in the forest-tundra ecotone. The ratio between fine roots of trees and stem biomass largely increased with elevation in both regions, but these increases were not accompanied by a distinct production of EMM. Production of EMM, however, increased with the presence of ectomycorrhizal trees at the transition from the tundra to the forest. Our results imply that the recorded upward expansion of forest into former tundra in the Ural Mountains by 4-8 m per decade is decreasing the partitioning of plant biomass to fine roots. They further suggest that climate-driven forest advances will alter EMM production rates with potential feedbacks on soil carbon and nutrient cycling in these ecosystems.

  14. Distribution of the root system of peach palm under drip irrigation

    Directory of Open Access Journals (Sweden)

    Adriano da Silva Lopes

    2014-07-01

    Full Text Available The incorporation of technologies has resulted in increased productivity and the more rational management of peach palm, with irrigation being an important tool for certain regions. Thus, studies leading to proper crop management are extremely important, such as the estimate of the effective depth of the root system, which is indispensable for proper irrigation management. The objective of this study was to evaluate the effects of different irrigation depths, as applied by drip irrigation, on the distribution of the root system of peach palm. This experiment was conducted in Ilha Solteira, São Paulo State, Brazil, with drip irrigation, with the two systems (flow of 0.0023 m3 h-1 consisting of four irrigation treatments corresponding to 0, 50, 100 and 150% of Class ‘A’ pan evaporation. After five years, an analysis of the Bactris gasipaes root system was performed at a distance of 0.0, 0.5 and 1.0 meters from the trunk, collecting sampling at two depths (0.0 to 0.3 m and 0.3 to 0.6 m via the auger method (volumetric analysis. We concluded that the effective depth of the root system used for irrigation management should be a maximum of 0.3 meters.

  15. The effect of four different irrigation systems in the removal of a root canal sealer.

    Science.gov (United States)

    Grischke, J; Müller-Heine, A; Hülsmann, M

    2014-09-01

    The aim of this study was to compare the efficiency of sonic, ultrasonic, and hydrodynamic devices in the removal of a root canal sealer from the surface and from simulated irregularities of root canals. Fifty-three root canals with two standardized grooves in the apical and coronal parts of longitudinally split roots were covered with AH Plus root canal sealer. Compared were the effects of (control) syringe irrigation, (1) CanalBrush, (2) passive ultrasonic irrigation, (3) EndoActivator, and (4) RinsEndo on the removal of the sealer. The specimens were divided into four groups (N = 12) and one control group (N = 5) via randomization. The amount of remaining sealer in the root canal irregularities was evaluated under a microscope using a 4-grade scoring system, whereas the remaining sealer on the root canal surface was evaluated with a 7-grade scoring system. Passive ultrasonic irrigation is more effective than the other tested irrigation systems or syringe irrigation in removing sealer from root canal walls (p irrigation shows a superior effect on sealer removal from the root canal surface during endodontic retreatment. Cleaning of lateral grooves seems not to be possible with one of the techniques investigated. Incomplete removal of root canal sealer during re-treatment may cause treatment failure. Passive Ultrasonic irrigation seems to be the most effective system to remove sealer from a root canal.

  16. Organic fertilization alters the community composition of root associated fungi in Pisum sativum

    DEFF Research Database (Denmark)

    Yu, L.; Nicolaisen, M.; Ravnskov, S.

    2013-01-01

    Organic fertilization is well known to affect individual functional groups of root associated fungi such as arbuscular mycorrhizal (AM) fungi and root pathogens, but limited information is available on the effect of organic fertilization at the fungal community composition level. The main objective...... of the present study was to examine the response of communities of root associated fungi in Pisum sativum to Protamylasse, an organic fertilizer used in pea production. Plants were grown in pots with field soil amended with four different levels of Protamylasse. 454 pyrosequencing was employed to examine......, the organic fertilizer Protamylasse clearly affects communities of root associated fungi, which seems to be linked to the life strategy of the different functional groups of root associated fungi. --------------------------------------------------------------------------------...

  17. Properties of Plasma Membrane from Pea Root Seedlings under Altered Gravity

    Science.gov (United States)

    Klymchuk, D.; Baranenko, V.; Vorobyova, T. V.; Kurylenko, I.; Chyzhykova, O.; Dubovoy, V.

    In this study, the properties of pea (Pisum sativum L.) plasma membrane were examined to determine how the membrane structure and functions are regulated in response to clinorotation (2 rev/min) conditions. Membrane preparations enriched by plasma membrane vesicles were obtained by aqueous two-phase partitioning from 6-day seedling roots. The specific characteristics of H^+-ATPase, lípid composition and peroxidation intensity as well as fluidity of lipid bilayer were analysed. ATP hydrolytic activity was inhibited by ortovanadate and was insensitive to aside and nitrate in sealed plasma membrane vesicles isolated from both clinorotated and control seedlings. Plasma membrane vesicles from clinorotated seedlings in comparison to controls were characterised by increase in the total lipid/protein ratio, ATP hydrolytic activity and intensifying of lipid peroxidation. Sitosterol and campesterol were the predominant free sterol species. Clinorotated seedlings contained a slightly higher level of unsaturated fatty acid than controls. Plasma membrane vesicles were labelled with pyrene and fluorescence originating from monomeric (I_M) molecules and excimeric (I_E) aggregates were measured. The calculated I_E/I_M values were higher in clinorotated seedlings compared with controls reflecting the reduction in membrane microviscosity. The involvement of the changes in plasma membrane lipid content and composition, fluidity and H^+-ATPase activity in response of pea seedlings to altered gravity is discussed.

  18. The function of root-systems in mineral nutrition of watercress (Rorippa nasturtium-Aquaticum (L) Hayek)

    International Nuclear Information System (INIS)

    Cumbus, I.P.; Robinson, L.W.

    1977-01-01

    The ability of 'adventitious' and 'basal' root systems of watercress (Rorippa nasturtium-aquaticum (L) Hayek) to absorb mineral nutrients from surrounding media is demonstrated using radioisotopes 32 P, 86 Rb and 59 Fe. Controlled experiments on single whole plants cultured in a dual-medium-apparatus, indicate that both root systems have a capacity for nutrient absorption. Analysis of axillary shoots formed during a seven day experimental period show that a greater proportion of phosphate and potassium, gained from the ambient media, was absorbed by the adventitious root system, although there was a greater mass of basal root tissue. Extensive translocation of nutrients to actively growing plant organs occurs from absorption sites on both root systems

  19. Locally Finite Root Supersystems

    OpenAIRE

    Yousofzadeh, Malihe

    2013-01-01

    We introduce the notion of locally finite root supersystems as a generalization of both locally finite root systems and generalized root systems. We classify irreducible locally finite root supersystems.

  20. Extension of the root-locus method to a certain class of fractional-order systems.

    Science.gov (United States)

    Merrikh-Bayat, Farshad; Afshar, Mahdi; Karimi-Ghartemani, Masoud

    2009-01-01

    In this paper, the well-known root-locus method is developed for the special subset of linear time-invariant systems commonly known as fractional-order systems. Transfer functions of these systems are rational functions with polynomials of rational powers of the Laplace variable s. Such systems are defined on a Riemann surface because of their multi-valued nature. A set of rules for plotting the root loci on the first Riemann sheet is presented. The important features of the classical root-locus method such as asymptotes, roots condition on the real axis and breakaway points are extended to the fractional case. It is also shown that the proposed method can assess the closed-loop stability of fractional-order systems in the presence of a varying gain in the loop. Moreover, the effect of perturbation on the root loci is discussed. Three illustrative examples are presented to confirm the effectiveness of the proposed algorithm.

  1. Impacts of deficit irrigation and altered rooting patterns on soil structure and associated soil properties

    Science.gov (United States)

    A better understanding of belowground systems and overall management impacts on soil health is needed to improve crop production and long-term sustainability under deficit irrigation. This study investigates effects of deficit irrigation on rooting patterns in maize and subsequent impacts on soil pr...

  2. RootJS: Node.js Bindings for ROOT 6

    Science.gov (United States)

    Beffart, Theo; Früh, Maximilian; Haas, Christoph; Rajgopal, Sachin; Schwabe, Jonas; Wolff, Christoph; Szuba, Marek

    2017-10-01

    We present rootJS, an interface making it possible to seamlessly integrate ROOT 6 into applications written for Node.js, the JavaScript runtime platform increasingly commonly used to create high-performance Web applications. ROOT features can be called both directly from Node.js code and by JIT-compiling C++ macros. All rootJS methods are invoked asynchronously and support callback functions, allowing non-blocking operation of Node.js applications using them. Last but not least, our bindings have been designed to platform-independent and should therefore work on all systems supporting both ROOT 6 and Node.js. Thanks to rootJS it is now possible to create ROOT-aware Web applications taking full advantage of the high performance and extensive capabilities of Node.js. Examples include platforms for the quality assurance of acquired, reconstructed or simulated data, book-keeping and e-log systems, and even Web browser-based data visualisation and analysis.

  3. Evaluation of the root canal shaping ability of two rotary nickel-titanium systems.

    Science.gov (United States)

    Al-Manei, K K; Al-Hadlaq, S M S

    2014-10-01

    The aim was to investigate the canal shaping abilities of the twisted file (TF) and GT series X file (GTX) systems. Sixty mesial root canals of mandibular molars with curvatures of 15-50° were divided randomly into two groups of 30 canals each. The teeth were sectioned horizontally at 3, 6 and 9 mm from the apex. Root canals were prepared with TF and GTX files, respectively, and the shaping abilities of the systems were evaluated at three levels (coronal, middle and apical) based on the comparison of pre- and post-instrumentation photographs using AutoCAD software. Preparation time was also assessed. Data from the two groups were compared statistically using the Student's t-test. There was no significant difference between the rotary systems in terms of change in root canal cross-sectional area, root canal transportation, centring ability or minimum dentine thickness. Remaining dentine thickness at the coronal and middle levels was similar in the TF and GTX groups, but GTX instruments left significantly less dentine than TF instruments on the mesial aspects of root canals at the apical level. Root canal preparation with TF instruments required significantly less time than with GTX instruments. The TF and GTX NiTi rotary instruments showed similar shaping abilities, but root canal preparation was more rapid with the TF than with the GTX system. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  4. Fagopyrum esculentum Alters Its Root Exudation after Amaranthus retroflexus Recognition and Suppresses Weed Growth.

    Science.gov (United States)

    Gfeller, Aurélie; Glauser, Gaétan; Etter, Clément; Signarbieux, Constant; Wirth, Judith

    2018-01-01

    Weed control by crops through growth suppressive root exudates is a promising alternative to herbicides. Buckwheat ( Fagopyrum esculentum ) is known for its weed suppression and redroot pigweed ( Amaranthus retroflexus ) control is probably partly due to allelopathic root exudates. This work studies whether other weeds are also suppressed by buckwheat and if the presence of weeds is necessary to induce growth repression. Buckwheat and different weeds were co-cultivated in soil, separating roots by a mesh allowing to study effects due to diffusion. Buckwheat suppressed growth of pigweed, goosefoot and barnyard grass by 53, 42, and 77% respectively without physical root interactions, probably through allelopathic compounds. Root exudates were obtained from sand cultures of buckwheat (BK), pigweed (P), and a buckwheat/pigweed mixed culture (BK-P). BK-P root exudates inhibited pigweed root growth by 49%. Characterization of root exudates by UHPLC-HRMS and principal component analysis revealed that BK and BK-P had a different metabolic profile suggesting that buckwheat changes its root exudation in the presence of pigweed indicating heterospecific recognition. Among the 15 different markers, which were more abundant in BK-P, tryptophan was identified and four others were tentatively identified. Our findings might contribute to the selection of crops with weed suppressive effects.

  5. Onion root tip cell system for biodosimetry?

    International Nuclear Information System (INIS)

    Paradiz, J; Druskovic, B.; Lovka, M.; Skrk, J.

    1996-01-01

    Methodology for radiation dose assessment based on chromosomal damage to plant cells has no yet been established, although root meristems have been the pioneer cytogenetic materials and profound analyses of irradiated meristematic cells of horse bean (Viciafaba L.) had been performed. Onion (Allium cepa L.) root tips frequently used for radiation cytogenetic studies, are recently considered to be one of the most promising plant test system for the detection of genotoxic environmental pollutants. We studied the possibility of using cytogenetic analyses of irradiated onion cells to determine the effective biological dose of ionizing radiation. The dose-effect relationships for chromosomal damages to onion meristematic cells were established after plants had been irradiated and subsequently grown in both laboratory and field conditions

  6. Arabidopsis pdr2 reveals a phosphate-sensitive checkpoint in root development.

    Science.gov (United States)

    Ticconi, Carla A; Delatorre, Carla A; Lahner, Brett; Salt, David E; Abel, Steffen

    2004-03-01

    Plants have evolved complex strategies to maintain phosphate (Pi) homeostasis and to maximize Pi acquisition when the macronutrient is limiting. Adjustment of root system architecture via changes in meristem initiation and activity is integral to the acclimation process. However, the mechanisms that monitor external Pi status and interpret the nutritional signal remain to be elucidated. Here, we present evidence that the Pi deficiency response, pdr2, mutation disrupts local Pi sensing. The sensitivity and amplitude of metabolic Pi-starvation responses, such as Pi-responsive gene expression or accumulation of anthocyanins and starch, are enhanced in pdr2 seedlings. However, the most conspicuous alteration of pdr2 is a conditional short-root phenotype that is specific for Pi deficiency and caused by selective inhibition of root cell division followed by cell death below a threshold concentration of about 0.1 mm external Pi. Measurements of general Pi uptake and of total phosphorus (P) in root tips exclude a defect in high-affinity Pi acquisition. Rescue of root meristem activity in Pi-starved pdr2 by phosphite (Phi), a non-metabolizable Pi analog, and divided-root experiments suggest that pdr2 disrupts sensing of low external Pi availability. Thus, PDR2 is proposed to function at a Pi-sensitive checkpoint in root development, which monitors environmental Pi status, maintains and fine-tunes meristematic activity, and finally adjusts root system architecture to maximize Pi acquisition.

  7. Tree root intrusion in sewer systems: A review of extent and costs

    Science.gov (United States)

    T.B. Randrup; E.G. McPherson; L.R. Costello

    2001-01-01

    Interference between trees and sewer systems is likely to occur in old systems and in cracked pipes. Factors that contribute to damage include old pipes with joints, shallow pipes, small-dimension pipes, and fast-growing tree species. Because roots are reported to cause >50% of all sewer blockages, costs associated with root removal from sewers is substantial. In...

  8. Study of the system of tuberous root induction in vitro from ...

    African Journals Online (AJOL)

    Abstract. This study investigated the induction system of tuberous root in vitro from Rehmannia glutinosa. The roles of plant growth substance, carbohydrates, and minerals were evaluated for induction and development of tuberous root in vitro. The results show that Murashige and Skoog (MS) contributed greatly to induction ...

  9. Farming system context drives the value of deep wheat roots in semi-arid environments.

    Science.gov (United States)

    Lilley, Julianne M; Kirkegaard, John A

    2016-06-01

    The capture of subsoil water by wheat roots can make a valuable contribution to grain yield on deep soils. More extensive root systems can capture more water, but leave the soil in a drier state, potentially limiting water availability to subsequent crops. To evaluate the importance of these legacy effects, a long-term simulation analysis at eight sites in the semi-arid environment of Australia compared the yield of standard wheat cultivars with cultivars that were (i) modified to have root systems which extract more water at depth and/or (ii) sown earlier to increase the duration of the vegetative period and hence rooting depth. We compared simulations with and without annual resetting of soil water to investigate the legacy effects of drier subsoils related to modified root systems. Simulated mean yield benefits from modified root systems declined from 0.1-0.6 t ha(-1) when annually reset, to 0-0.2 t ha(-1) in the continuous simulation due to a legacy of drier soils (mean 0-32mm) at subsequent crop sowing. For continuous simulations, predicted yield benefits of >0.2 t ha(-1) from more extensive root systems were rare (3-10% of years) at sites with shallow soils (<1.0 m), but occurred in 14-44% of years at sites with deeper soils (1.6-2.5 m). Earlier sowing had a larger impact than modified root systems on water uptake (14-31 vs 2-17mm) and mean yield increase (up to 0.7 vs 0-0.2 t ha(-1)) and the benefits occurred on deep and shallow soils and in more years (9-79 vs 3-44%). Increasing the proportion of crops in the sequence which dry the subsoil extensively has implications for the farming system productivity, and the crop sequence must be managed tactically to optimize overall system benefits. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  10. Roles of abscisic acid and auxin in shoot-supplied ammonium inhibition of root system development

    OpenAIRE

    Li, Baohai; Li, Qing; Kronzucker, Herbert J; Shi, Weiming

    2011-01-01

    A plastic root system is a prerequisite for successful plant acclimation to variable environments. The normally functioning root system is the result of a complex interaction of root-borne signals and shoot-derived regulators. We recently demonstrated that AUX1, a well-studied component of auxin transport, mediates shoot-supplied ammonium (SSA) inhibition of lateral root (LR) formation in Arabidopsis. By contrast, the response did not involve ABA pathways, via which several other abiotic stre...

  11. Analisis Pindah Panas pada Pipa Pendingin untuk Root Zone Cooling System

    Directory of Open Access Journals (Sweden)

    Nurbaiti Araswati

    2017-12-01

    Full Text Available Root zone cooling system is needed to alleviate high-temperature injury for high-yield greenhouse vegetables production. Analysis of heat transfer along the cooling pipe is very important in designing the root zone cooling system. The objectives of this research were (1 to analyze heat transfer in cooling pipe for zone cooling in a hydroponic system, (2 to validate the heat transfer dynamics model to predict the water temperature at the outlet of the cooling pipe, and (3 to perform model simulations for various types of pipe materials and lengths in several thermal conditions in the greenhouse. Root zone cooling system was performed by flowing water (10oC through a steel pipe along 25 m to the root zone. The analysis showed a decrease up to 2.8oC in the planting medium temperature 28.6oC from control 31.4oC. The validation of heat transfer model was conducted by comparing the predicted water temperature to that of measured on linear regression plot. The result showed a straight line Y=1.0026X and the coefficient of determination (R2 0.9867. Based on data analysis, the temperature of water reaches 1oC in steel and copper cooling pipes along 40 m and significantly different from the PVC that is 0.8oC.

  12. A drought resistance-promoting microbiome is selected by root system under desert farming.

    Directory of Open Access Journals (Sweden)

    Ramona Marasco

    Full Text Available BACKGROUND: Traditional agro-systems in arid areas are a bulwark for preserving soil stability and fertility, in the sight of "reverse desertification". Nevertheless, the impact of desert farming practices on the diversity and abundance of the plant associated microbiome is poorly characterized, including its functional role in supporting plant development under drought stress. METHODOLOGY/PRINCIPAL FINDINGS: We assessed the structure of the microbiome associated to the drought-sensitive pepper plant (Capsicum annuum L. cultivated in a traditional Egyptian farm, focusing on microbe contribution to a crucial ecosystem service, i.e. plant growth under water deficit. The root system was dissected by sampling root/soil with a different degree of association to the plant: the endosphere, the rhizosphere and the root surrounding soil that were compared to the uncultivated soil. Bacterial community structure and diversity, determined by using Denaturing Gradient Gel Electrophoresis, differed according to the microhabitat, indicating a selective pressure determined by the plant activity. Similarly, culturable bacteria genera showed different distribution in the three root system fractions. Bacillus spp. (68% of the isolates were mainly recovered from the endosphere, while rhizosphere and the root surrounding soil fractions were dominated by Klebsiella spp. (61% and 44% respectively. Most of the isolates (95% presented in vitro multiple plant growth promoting (PGP activities and stress resistance capabilities, but their distribution was different among the root system fractions analyzed, with enhanced abilities for Bacillus and the rhizobacteria strains. We show that the C. annuum rhizosphere under desert farming enriched populations of PGP bacteria capable of enhancing plant photosynthetic activity and biomass synthesis (up to 40% under drought stress. CONCLUSIONS/SIGNIFICANCE: Crop cultivation provides critical ecosystem services in arid lands with the

  13. Root anatomical phenes predict root penetration ability and biomechanical properties in maize (Zea Mays)

    OpenAIRE

    Chimungu, Joseph G.; Loades, Kenneth W.; Lynch, Jonathan P.

    2015-01-01

    The ability of roots to penetrate hard soil is important for crop productivity but specific root phenes contributing to this ability are poorly understood. Root penetrability and biomechanical properties are likely to vary in the root system dependent on anatomical structure. No information is available to date on the influence of root anatomical phenes on root penetrability and biomechanics. Root penetration ability was evaluated using a wax layer system. Root tensile and bending strength we...

  14. Isolation and characterization of altered root growth behavior and ...

    African Journals Online (AJOL)

    Generation, screening and isolating mutants for any developmental and adaptive traits plays a major role in plant functional genomics research. Identification and exploitation of mutants possessing contrasting root growth behavior and salinity tolerance in rice will help us to identify key genes controlling these traits and in ...

  15. The jasmonate receptor COI1 plays a role in jasmonate-induced lateral root formation and lateral root positioning in Arabidopsis thaliana.

    Science.gov (United States)

    Raya-González, Javier; Pelagio-Flores, Ramón; López-Bucio, José

    2012-09-15

    Jasmonic acid (JA) regulates a broad range of plant defense and developmental responses. COI1 has been recently found to act as JA receptor. In this report, we show that low micromolar concentrations of JA inhibited primary root (PR) growth and promoted lateral root (LR) formation in Arabidopsis wild-type (WT) seedlings. It was observed that the coi1-1 mutant was less sensitive to JA on pericycle cell activation to induce lateral root primordia (LRP) formation and presented alterations in lateral root positioning and lateral root emergence on bends. To investigate JA-auxin interactions important for remodeling of root system (RS) architecture, we tested the expression of auxin-inducible markers DR5:uidA and BA3:uidA in WT and coi1-1 seedlings in response to indole-3-acetic acid (IAA) and JA and analyzed the RS architecture of a suite of auxin-related mutants under JA treatments. We found that JA did not affect DR5:uidA and BA3:uidA expression in WT and coi1-1 seedlings. Our data also showed that PR growth inhibition in response to JA was likely independent of auxin signaling and that the induction of LRP required ARF7, ARF19, SLR, TIR1, AFB2, AFB3 and AXR1 loci. We conclude that JA regulation of postembryonic root development involves both auxin-dependent and independent mechanisms. Copyright © 2012 Elsevier GmbH. All rights reserved.

  16. Root nodule symbiosis in Lotus japonicus drives the establishment of distinctive rhizosphere, root, and nodule bacterial communities.

    Science.gov (United States)

    Zgadzaj, Rafal; Garrido-Oter, Ruben; Jensen, Dorthe Bodker; Koprivova, Anna; Schulze-Lefert, Paul; Radutoiu, Simona

    2016-12-06

    Lotus japonicus has been used for decades as a model legume to study the establishment of binary symbiotic relationships with nitrogen-fixing rhizobia that trigger root nodule organogenesis for bacterial accommodation. Using community profiling of 16S rRNA gene amplicons, we reveal that in Lotus, distinctive nodule- and root-inhabiting communities are established by parallel, rather than consecutive, selection of bacteria from the rhizosphere and root compartments. Comparative analyses of wild-type (WT) and symbiotic mutants in Nod factor receptor5 (nfr5), Nodule inception (nin) and Lotus histidine kinase1 (lhk1) genes identified a previously unsuspected role of the nodulation pathway in the establishment of different bacterial assemblages in the root and rhizosphere. We found that the loss of nitrogen-fixing symbiosis dramatically alters community structure in the latter two compartments, affecting at least 14 bacterial orders. The differential plant growth phenotypes seen between WT and the symbiotic mutants in nonsupplemented soil were retained under nitrogen-supplemented conditions that blocked the formation of functional nodules in WT, whereas the symbiosis-impaired mutants maintain an altered community structure in the nitrogen-supplemented soil. This finding provides strong evidence that the root-associated community shift in the symbiotic mutants is a direct consequence of the disabled symbiosis pathway rather than an indirect effect resulting from abolished symbiotic nitrogen fixation. Our findings imply a role of the legume host in selecting a broad taxonomic range of root-associated bacteria that, in addition to rhizobia, likely contribute to plant growth and ecological performance.

  17. Changes in hormonal balance and meristematic activity in primary root tips on the slowly rotating clinostat and their effect on the development of the rapeseed root system.

    Science.gov (United States)

    Aarrouf, J; Schoevaert, D; Maldiney, R; Perbal, G

    1999-04-01

    The morphometry of the root system, the meristematic activity and the level of indole-3-acetic acid (IAA), abscisic acid (ABA) and zeatin in the primary root tips of rapeseed seedlings were analyzed as functions of time on a slowly rotating clinostat (1 rpm) or in the vertical controls (1 rpm). The fresh weight of the root system was 30% higher throughout the growth period (25 days) in clinorotated seedlings. Morphometric analysis showed that the increase in biomass on the clinostat was due to greater primary root growth, earlier initiation and greater elongation of the secondary roots, which could be observed even in 5-day-old seedlings. However, after 15 days, the growth of the primary root slowed on the clinostat, whereas secondary roots still grew faster in clinorotated plants than in the controls. At this time, the secondary roots began to be initiated closer to the root tip on the clinostat than in the control. Analysis of the meristematic activity and determination of the levels in IAA, ABA and zeatin in the primary root tips demonstrated that after 5 days on the clinostat, the increased length of the primary root could be the consequence of higher meristematic activity and coincided with an increase in both IAA and ABA concentrations. After 15 days on the clinostat, a marked increase in IAA, ABA and zeatin, which probably reached supraoptimal levels, seems to cause a progressive disturbance of the meristematic cells, during a decrease of primary root growth between 15 and 25 days. These modifications in the hormonal balance and the perturbation of the meristematic activity on the clinostat were followed by a loss of apical dominance, which was responsible for the early initiation of secondary roots, the greater elongation of the root system and the emergence of the lateral roots near the tip of the primary root.

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

    OpenAIRE

    Danjon, Frédéric; Caplan, Joshua S.; Fortin, Mathieu; Meredieu, Céline

    2013-01-01

    Root systems of woody plants generally display a strong relationship between the cross-sectional area 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 a 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 ...

  19. Root biomass, turnover and net primary productivity of a coffee agroforestry system in Costa Rica: effects of soil depth, shade trees, distance to row and coffee age.

    Science.gov (United States)

    Defrenet, Elsa; Roupsard, Olivier; Van den Meersche, Karel; Charbonnier, Fabien; Pastor Pérez-Molina, Junior; Khac, Emmanuelle; Prieto, Iván; Stokes, Alexia; Roumet, Catherine; Rapidel, Bruno; de Melo Virginio Filho, Elias; Vargas, Victor J; Robelo, Diego; Barquero, Alejandra; Jourdan, Christophe

    2016-08-21

    In Costa Rica, coffee (Coffea arabica) plants are often grown in agroforests. However, it is not known if shade-inducing trees reduce coffee plant biomass through root competition, and hence alter overall net primary productivity (NPP). We estimated biomass and NPP at the stand level, taking into account deep roots and the position of plants with regard to trees. Stem growth and root biomass, turnover and decomposition were measured in mixed coffee/tree (Erythrina poeppigiana) plantations. Growth ring width and number at the stem base were estimated along with stem basal area on a range of plant sizes. Root biomass and fine root density were measured in trenches to a depth of 4 m. To take into account the below-ground heterogeneity of the agroforestry system, fine root turnover was measured by sequential soil coring (to a depth of 30 cm) over 1 year and at different locations (in full sun or under trees and in rows/inter-rows). Allometric relationships were used to calculate NPP of perennial components, which was then scaled up to the stand level. Annual ring width at the stem base increased up to 2·5 mm yr -1 with plant age (over a 44-year period). Nearly all (92 %) coffee root biomass was located in the top 1·5 m, and only 8 % from 1·5 m to a depth of 4 m. Perennial woody root biomass was 16 t ha -1 and NPP of perennial roots was 1·3 t ha -1 yr -1 Fine root biomass (0-30 cm) was two-fold higher in the row compared with between rows. Fine root biomass was 2·29 t ha -1 (12 % of total root biomass) and NPP of fine roots was 2·96 t ha -1 yr -1 (69 % of total root NPP). Fine root turnover was 1·3 yr -1 and lifespan was 0·8 years. Coffee root systems comprised 49 % of the total plant biomass; such a high ratio is possibly a consequence of shoot pruning. There was no significant effect of trees on coffee fine root biomass, suggesting that coffee root systems are very competitive in the topsoil. © The Author 2016. Published by Oxford University Press on

  20. Root Zone Respiration on Hydroponically Grown Wheat Plant Systems

    Science.gov (United States)

    Soler-Crespo, R. A.; Monje, O. A.

    2010-01-01

    Root respiration is a biological phenomenon that controls plant growth and physiological development during a plant's lifespan. This process is dependent on the availability of oxygen in the system where the plant is located. In hydroponic systems, where plants are submerged in a solution containing vital nutrients but no type of soil, the availability of oxygen arises from the dissolved oxygen concentration in the solution. This oxygen concentration is dependent on the , gas-liquid interface formed on the upper surface of the liquid, as given by Henry's Law, depending on pressure and temperature conditions. Respiration rates of the plants rise as biomass and root zone increase with age. The respiration rate of Apogee wheat plants (Triticum aestivum) was measured as a function of light intensity (catalytic for photosynthesis) and CO2 concentration to determine their effect on respiration rates. To determine their effects on respiration rate and plant growth microbial communities were introduced into the system, by Innoculum. Surfactants were introduced, simulating gray-water usage in space, as another factor to determine their effect on chemical oxygen demand of microbials and on respiration rates of the plants. It is expected to see small effects from changes in CO2 concentration or light levels, and to see root respiration decrease in an exponential manner with plant age and microbial activity.

  1. GROWTH AND ROOTING SYSTEM OF ACACIA MANGIUM OBTAINED BY TISSUE CULTURE

    Directory of Open Access Journals (Sweden)

    SUPRIYANTO

    1991-01-01

    Full Text Available Since 1980/1981, the government of Indonesia through the Ministry of Forestry has started to reforest logged-over, alang-alang, unproductive areas and to convert them to Forest Industry Plantation. The target is 300 000 ha per year. It means, 750 million seedlings should be provided per year (planting distance 2 m x 2 m. The tree species to be planted in forest industry plantation should have shorter life cycle (8 - 10 years, good stem-form, good rooting system, and should be fast growing. Acacia mangium has been selected as one of the important tree species for forest industry plantation due to its growth, quality of fiber wood (pulp and paper industry and rooting system (produce a lot of secondary root and nitrogen fixater (Soebardjo 1986. The reforestation of logged-over Dipterocarp forests in Malaysia with A. mangium has also been considered (Appanah and Weinland 1989. Generally, reforestation with A. mangium is done with seedlings obtained by seed germination. A. mangium produce a lot of seeds but its production is still limited by the season, while the conventional method of vegetative propagation through cuttings gave very low percentage of rooted-cuttings (1% (Umboh and Syamsul Yani 1989. The micropropagation of A. mangium through tissue culture is a promising method. The production of A. mangium plantlets through that method has been done at the Forest Genetic Laboratory, Tropical Forest Biology, SEAMEO BIOTROP (Situmorang 1988, Umboh 1988, Umboh et al. 1989, 1990. These rooted-plantlets (plantlings were first put in the green house (acclimatization before planting in the field. Field tests of some agricultural plants have been done but information on forest trees species is still lacking because the production of plantlings through tissue culture is still limited as there are still problems of their rooting. In fact, the progress of reproducing woody plants by tissue culture has been much slower than with herbaceous plants. The major

  2. Roles of abscisic acid and auxin in shoot-supplied ammonium inhibition of root system development.

    Science.gov (United States)

    Li, Baohai; Li, Qing; Kronzucker, Herbert J; Shi, Weiming

    2011-10-01

    A plastic root system is a prerequisite for successful plant acclimation to variable environments. The normally functioning root system is the result of a complex interaction of root-borne signals and shoot-derived regulators. We recently demonstrated that AUX1, a well-studied component of auxin transport, mediates shoot-supplied ammonium (SSA) inhibition of lateral root (LR) formation in Arabidopsis. By contrast, the response did not involve ABA pathways, via which several other abiotic stresses affect LR formation. We proposed that SSA regulates LR emergence by interrupting AUX1-mediated auxin transport from shoot to root. Here, by analyzing both ABA- and auxin-related mutants, we show that AUX1 is also required for SSA-mediated suppression of primary root growth. Ammonium content in shoots was furthermore shown to increase linearly with shoot-, but not root-supplied, ammonium, suggesting it may represent the internal trigger for SSA inhibition of root development. Taken together, our data identify AUX1-mediated auxin transport as a key transmission step in the sensing of excessive ammonium exposure and its inhibitory effect on root development. 

  3. Food for thought: how nutrients regulate root system architecture.

    Science.gov (United States)

    Shahzad, Zaigham; Amtmann, Anna

    2017-10-01

    The spatial arrangement of the plant root system (root system architecture, RSA) is very sensitive to edaphic and endogenous signals that report on the nutrient status of soil and plant. Signalling pathways underpinning RSA responses to individual nutrients, particularly nitrate and phosphate, have been unravelled. Researchers have now started to investigate interactive effects between two or more nutrients on RSA. Several proteins enabling crosstalk between signalling pathways have recently been identified. RSA is potentially an important trait for sustainable and/or marginal agriculture. It is generally assumed that RSA responses are adaptive and optimise nutrient uptake in a given environment, but hard evidence for this paradigm is still sparse. Here we summarize recent advances made in these areas of research. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Numeral-Incorporating Roots in Numeral Systems: A Comparative Analysis of Two Sign Languages

    Science.gov (United States)

    Fuentes, Mariana; Massone, Maria Ignacia; Fernandez-Viader, Maria del Pilar; Makotrinsky, Alejandro; Pulgarin, Francisca

    2010-01-01

    Numeral-incorporating roots in the numeral systems of Argentine Sign Language (LSA) and Catalan Sign Language (LSC), as well as the main features of the number systems of both languages, are described and compared. Informants discussed the use of numerals and roots in both languages (in most cases in natural contexts). Ten informants took part in…

  5. Pb-induced cellular defense system in the root meristematic cells of Allium sativum L.

    Science.gov (United States)

    Jiang, Wusheng; Liu, Donghua

    2010-03-02

    Electron microscopy (EM) techniques enable identification of the main accumulations of lead (Pb) in cells and cellular organelles and observations of changes in cell ultrastructure. Although there is extensive literature relating to studies on the influence of heavy metals on plants, Pb tolerance strategies of plants have not yet been fully explained. Allium sativum L. is a potential plant for absorption and accumulation of heavy metals. In previous investigations the effects of different concentrations (10(-5) to 10(-3) M) of Pb were investigated in A. sativum, indicating a significant inhibitory effect on shoot and root growth at 10(-3) to 10(-4) M Pb. In the present study, we used EM and cytochemistry to investigate ultrastructural alterations, identify the synthesis and distribution of cysteine-rich proteins induced by Pb and explain the possible mechanisms of the Pb-induced cellular defense system in A. sativum. After 1 h of Pb treatment, dictyosomes were accompanied by numerous vesicles within cytoplasm. The endoplasm reticulum (ER) with swollen cisternae was arranged along the cell wall after 2 h. Some flattened cisternae were broken up into small closed vesicles and the nuclear envelope was generally more dilated after 4 h. During 24-36 h, phenomena appeared such as high vacuolization of cytoplasm and electron-dense granules in cell walls, vacuoles, cytoplasm and mitochondrial membranes. Other changes included mitochondrial swelling and loss of cristae, and vacuolization of ER and dictyosomes during 48-72 h. In the Pb-treatment groups, silver grains were observed in cell walls and in cytoplasm, suggesting the Gomori-Swift reaction can indirectly evaluate the Pb effects on plant cells. Cell walls can immobilize some Pb ions. Cysteine-rich proteins in cell walls were confirmed by the Gomori-Swift reaction. The morphological alterations in plasma membrane, dictyosomes and ER reflect the features of detoxification and tolerance under Pb stress. Vacuoles are

  6. Pb-induced cellular defense system in the root meristematic cells of Allium sativum L

    Directory of Open Access Journals (Sweden)

    Liu Donghua

    2010-03-01

    Full Text Available Abstract Background Electron microscopy (EM techniques enable identification of the main accumulations of lead (Pb in cells and cellular organelles and observations of changes in cell ultrastructure. Although there is extensive literature relating to studies on the influence of heavy metals on plants, Pb tolerance strategies of plants have not yet been fully explained. Allium sativum L. is a potential plant for absorption and accumulation of heavy metals. In previous investigations the effects of different concentrations (10-5 to 10-3 M of Pb were investigated in A. sativum, indicating a significant inhibitory effect on shoot and root growth at 10-3 to 10-4 M Pb. In the present study, we used EM and cytochemistry to investigate ultrastructural alterations, identify the synthesis and distribution of cysteine-rich proteins induced by Pb and explain the possible mechanisms of the Pb-induced cellular defense system in A. sativum. Results After 1 h of Pb treatment, dictyosomes were accompanied by numerous vesicles within cytoplasm. The endoplasm reticulum (ER with swollen cisternae was arranged along the cell wall after 2 h. Some flattened cisternae were broken up into small closed vesicles and the nuclear envelope was generally more dilated after 4 h. During 24-36 h, phenomena appeared such as high vacuolization of cytoplasm and electron-dense granules in cell walls, vacuoles, cytoplasm and mitochondrial membranes. Other changes included mitochondrial swelling and loss of cristae, and vacuolization of ER and dictyosomes during 48-72 h. In the Pb-treatment groups, silver grains were observed in cell walls and in cytoplasm, suggesting the Gomori-Swift reaction can indirectly evaluate the Pb effects on plant cells. Conclusions Cell walls can immobilize some Pb ions. Cysteine-rich proteins in cell walls were confirmed by the Gomori-Swift reaction. The morphological alterations in plasma membrane, dictyosomes and ER reflect the features of detoxification

  7. OpenSimRoot: widening the scope and application of root architectural models.

    Science.gov (United States)

    Postma, Johannes A; Kuppe, Christian; Owen, Markus R; Mellor, Nathan; Griffiths, Marcus; Bennett, Malcolm J; Lynch, Jonathan P; Watt, Michelle

    2017-08-01

    OpenSimRoot is an open-source, functional-structural plant model and mathematical description of root growth and function. We describe OpenSimRoot and its functionality to broaden the benefits of root modeling to the plant science community. OpenSimRoot is an extended version of SimRoot, established to simulate root system architecture, nutrient acquisition and plant growth. OpenSimRoot has a plugin, modular infrastructure, coupling single plant and crop stands to soil nutrient and water transport models. It estimates the value of root traits for water and nutrient acquisition in environments and plant species. The flexible OpenSimRoot design allows upscaling from root anatomy to plant community to estimate the following: resource costs of developmental and anatomical traits; trait synergisms; and (interspecies) root competition. OpenSimRoot can model three-dimensional images from magnetic resonance imaging (MRI) and X-ray computed tomography (CT) of roots in soil. New modules include: soil water-dependent water uptake and xylem flow; tiller formation; evapotranspiration; simultaneous simulation of mobile solutes; mesh refinement; and root growth plasticity. OpenSimRoot integrates plant phenotypic data with environmental metadata to support experimental designs and to gain a mechanistic understanding at system scales. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  8. The root/rhizome system of seagrasses: an asset and a burden

    Science.gov (United States)

    Hemminga, M. A.

    1998-06-01

    Large-scale declines in seagrass vegetation have been frequently observed in recent decades. Many of these declines can be traced to the reduction of light levels in the water column. In this paper, it is argued that the root/rhizome system offers a competitive advantage in nutrient-poor waters, but that it makes the plant vulnerable when changes in water quality lead to reduction of incident light. Seagrasses are capable of exploiting the nutrient stocks of both the water column and the sediment pore water, by leaves and roots, respectively. A survey of the literature shows that the median concentrations of water-column ammonium and phosphate in seagrass beds worldwide are 1.7 and 0.35 μM, respectively, whereas the same compounds in the pore water of the root zone reach median concentrations of 60 and 6.5 μM. The dual possibilities for nutrient uptake may underlie the apparent lack of strongly developed nutrient conservation strategies in seagrasses. The possession of roots becomes a disadvantage when the photosynthetically active radiation available to the plants decreases. At saturating light levels, the maximum rate of net photosynthesis (measured as O 2 production) of the leaves typically exceeds leaf respiration (measured as O 2 consumption) about 5 times. In low-light environments, the respiring below-ground biomass (which can greatly exceed the above-ground biomass) can be a considerable burden to the carbon balance of the plant, limiting its survival potential. In addition, secondary and tertiary effects of light reduction involving the roots and rhizomes may undermine plant vitality as well. Leaf photosynthesis is the major source of oxygen for the roots and rhizomes. Hence, decreased photosynthetic activity following light reduction may lead to hypoxic or anoxic conditions in the below-ground organs, presumably making them vulnerable to carbon starvation. A decreased flux of oxygen to the roots and rhizomes also restricts the possibilities for

  9. Analysis of Gene expression in soybean (Glycine max roots in response to the root knot nematode Meloidogyne incognita using microarrays and KEGG pathways

    Directory of Open Access Journals (Sweden)

    Gamal El-Din Abd El Kader Y

    2011-05-01

    Full Text Available Abstract Background Root-knot nematodes are sedentary endoparasites that can infect more than 3000 plant species. Root-knot nematodes cause an estimated $100 billion annual loss worldwide. For successful establishment of the root-knot nematode in its host plant, it causes dramatic morphological and physiological changes in plant cells. The expression of some plant genes is altered by the nematode as it establishes its feeding site. Results We examined the expression of soybean (Glycine max genes in galls formed in roots by the root-knot nematode, Meloidogyne incognita, 12 days and 10 weeks after infection to understand the effects of infection of roots by M. incognita. Gene expression was monitored using the Affymetrix Soybean GeneChip containing 37,500 G. max probe sets. Gene expression patterns were integrated with biochemical pathways from the Kyoto Encyclopedia of Genes and Genomes using PAICE software. Genes encoding enzymes involved in carbohydrate and cell wall metabolism, cell cycle control and plant defense were altered. Conclusions A number of different soybean genes were identified that were differentially expressed which provided insights into the interaction between M. incognita and soybean and into the formation and maintenance of giant cells. Some of these genes may be candidates for broadening plants resistance to root-knot nematode through over-expression or silencing and require further examination.

  10. Solving polynomial systems using no-root elimination blending schemes

    KAUST Repository

    Barton, Michael

    2011-01-01

    Searching for the roots of (piecewise) polynomial systems of equations is a crucial problem in computer-aided design (CAD), and an efficient solution is in strong demand. Subdivision solvers are frequently used to achieve this goal; however

  11. Facilitative root interactions in intercrops

    DEFF Research Database (Denmark)

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

    2005-01-01

    of root architecture, exudation of growth stimulating substances, and biofumigation. Facilitative root interactions are most likely to be of importance in nutrient poor soils and in low-input agroecosystems due to critical interspecific competition for plant growth factors. However, studies from more...... nitrogen transfer between legumes and non-leguminous plants, exploitation of the soil via mycorrhizal fungi and soil-plant processes which alter the mobilisation of plant growth resources such as through exudation of amino acids, extra-cellular enzymes, acidification, competition-induced modification......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...

  12. Rhizoslides: paper-based growth system for non-destructive, high throughput phenotyping of root development by means of image analysis.

    Science.gov (United States)

    Le Marié, Chantal; Kirchgessner, Norbert; Marschall, Daniela; Walter, Achim; Hund, Andreas

    2014-01-01

    A quantitative characterization of root system architecture is currently being attempted for various reasons. Non-destructive, rapid analyses of root system architecture are difficult to perform due to the hidden nature of the root. Hence, improved methods to measure root architecture are necessary to support knowledge-based plant breeding and to analyse root growth responses to environmental changes. Here, we report on the development of a novel method to reveal growth and architecture of maize root systems. The method is based on the cultivation of different root types within several layers of two-dimensional, large (50 × 60 cm) plates (rhizoslides). A central plexiglass screen stabilizes the system and is covered on both sides with germination paper providing water and nutrients for the developing root, followed by a transparent cover foil to prevent the roots from falling dry and to stabilize the system. The embryonic roots grow hidden between a Plexiglas surface and paper, whereas crown roots grow visible between paper and the transparent cover. Long cultivation with good image quality up to 20 days (four fully developed leaves) was enhanced by suppressing fungi with a fungicide. Based on hyperspectral microscopy imaging, the quality of different germination papers was tested and three provided sufficient contrast to distinguish between roots and background (segmentation). Illumination, image acquisition and segmentation were optimised to facilitate efficient root image analysis. Several software packages were evaluated with regard to their precision and the time investment needed to measure root system architecture. The software 'Smart Root' allowed precise evaluation of root development but needed substantial user interference. 'GiaRoots' provided the best segmentation method for batch processing in combination with a good analysis of global root characteristics but overestimated root length due to thinning artefacts. 'WhinRhizo' offered the most rapid

  13. Multi-frequency electrical impedance tomography as a non-invasive tool to characterize and monitor crop root systems

    Science.gov (United States)

    Weigand, Maximilian; Kemna, Andreas

    2017-02-01

    A better understanding of root-soil interactions and associated processes is essential in achieving progress in crop breeding and management, prompting the need for high-resolution and non-destructive characterization methods. To date, such methods are still lacking or restricted by technical constraints, in particular the charactization and monitoring of root growth and function in the field. A promising technique in this respect is electrical impedance tomography (EIT), which utilizes low-frequency (response in alternating electric-current fields due to electrical double layers which form at cell membranes. This double layer is directly related to the electrical surface properties of the membrane, which in turn are influenced by nutrient dynamics (fluxes and concentrations on both sides of the membranes). Therefore, it can be assumed that the electrical polarization properties of roots are inherently related to ion uptake and translocation processes in the root systems. We hereby propose broadband (mHz to hundreds of Hz) multi-frequency EIT as a non-invasive methodological approach for the monitoring and physiological, i.e., functional, characterization of crop root systems. The approach combines the spatial-resolution capability of an imaging method with the diagnostic potential of electrical-impedance spectroscopy. The capability of multi-frequency EIT to characterize and monitor crop root systems was investigated in a rhizotron laboratory experiment, in which the root system of oilseed plants was monitored in a water-filled rhizotron, that is, in a nutrient-deprived environment. We found a low-frequency polarization response of the root system, which enabled the successful delineation of its spatial extension. The magnitude of the overall polarization response decreased along with the physiological decay of the root system due to the stress situation. Spectral polarization parameters, as derived from a pixel-based Debye decomposition analysis of the multi

  14. Modification of antioxidant systems in cell walls of maize roots by different nitrogen sources

    International Nuclear Information System (INIS)

    Hadži-Tašković Šukalović V; Vuletić, M.; Marković, K.; Željko, Vučinić; Kravić, N.

    2016-01-01

    Antioxidant systems of maize root cell walls grown on different nitrogen sources were evaluated. Plants were grown on a medium containing only NO3- or the mixture of NO3-+NH4+, in a 2:1 ratio. Eleven-day old plants, two days after the initiation of lateral roots, were used for the experiments. Cell walls were isolated from lateral roots and primary root segments, 2-7 cm from tip to base, representing zones of intense or decreased growth rates, respectively. Protein content and the activity of enzymes peroxidase, malate dehydrogenase and ascorbate oxidase ionically or covalently bound to the walls, as well as cell wall phenolic content and antioxidant capacity, were determined. Cell walls of plants grown on mixed N possess more developed enzymatic antioxidant systems and lower non-enzymatic antioxidant defenses than cell walls grown on NO3-. Irrespective of N treatment, the activities of all studied enzymes and protein content were higher in cell walls of lateral compared to primary roots. Phenolic content of cell walls isolated from lateral roots was higher in NO3--grown than in mixed N grown plants. No significant differences could be observed in the isozyme patterns of cell wall peroxidases isolated from plants grown on different nutrient solution. Our results indicate that different N treatments modify the antioxidant systems of root cell walls. Treatment with NO3- resulted in an increase of constitutive phenolic content, while the combination of NO3-+NH4+ elevated the redox enzyme activities in root cell walls.

  15. Modification of antioxidant systems in cell walls of maize roots by different nitrogen sources

    Energy Technology Data Exchange (ETDEWEB)

    Hadži-Tašković Šukalović V; Vuletić, M.; Marković, K.; Željko, Vučinić; Kravić, N.

    2016-07-01

    Antioxidant systems of maize root cell walls grown on different nitrogen sources were evaluated. Plants were grown on a medium containing only NO3- or the mixture of NO3-+NH4+, in a 2:1 ratio. Eleven-day old plants, two days after the initiation of lateral roots, were used for the experiments. Cell walls were isolated from lateral roots and primary root segments, 2-7 cm from tip to base, representing zones of intense or decreased growth rates, respectively. Protein content and the activity of enzymes peroxidase, malate dehydrogenase and ascorbate oxidase ionically or covalently bound to the walls, as well as cell wall phenolic content and antioxidant capacity, were determined. Cell walls of plants grown on mixed N possess more developed enzymatic antioxidant systems and lower non-enzymatic antioxidant defenses than cell walls grown on NO3-. Irrespective of N treatment, the activities of all studied enzymes and protein content were higher in cell walls of lateral compared to primary roots. Phenolic content of cell walls isolated from lateral roots was higher in NO3--grown than in mixed N grown plants. No significant differences could be observed in the isozyme patterns of cell wall peroxidases isolated from plants grown on different nutrient solution. Our results indicate that different N treatments modify the antioxidant systems of root cell walls. Treatment with NO3- resulted in an increase of constitutive phenolic content, while the combination of NO3-+NH4+ elevated the redox enzyme activities in root cell walls.

  16. Genetic variants associated with the root system architecture of oilseed rape (Brassica napus L.) under contrasting phosphate supply.

    Science.gov (United States)

    Wang, Xiaohua; Chen, Yanling; Thomas, Catherine L; Ding, Guangda; Xu, Ping; Shi, Dexu; Grandke, Fabian; Jin, Kemo; Cai, Hongmei; Xu, Fangsen; Yi, Bin; Broadley, Martin R; Shi, Lei

    2017-08-01

    Breeding crops with ideal root system architecture for efficient absorption of phosphorus is an important strategy to reduce the use of phosphate fertilizers. To investigate genetic variants leading to changes in root system architecture, 405 oilseed rape cultivars were genotyped with a 60K Brassica Infinium SNP array in low and high P environments. A total of 285 single-nucleotide polymorphisms were associated with root system architecture traits at varying phosphorus levels. Nine single-nucleotide polymorphisms corroborate a previous linkage analysis of root system architecture quantitative trait loci in the BnaTNDH population. One peak single-nucleotide polymorphism region on A3 was associated with all root system architecture traits and co-localized with a quantitative trait locus for primary root length at low phosphorus. Two more single-nucleotide polymorphism peaks on A5 for root dry weight at low phosphorus were detected in both growth systems and co-localized with a quantitative trait locus for the same trait. The candidate genes identified on A3 form a haplotype 'BnA3Hap', that will be important for understanding the phosphorus/root system interaction and for the incorporation into Brassica napus breeding programs. © The Author 2017. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

  17. STUDYING FOREST ROOT SYSTEMS - AN OVERVIEW OF METHODOLOGICAL PROBLEMS

    Science.gov (United States)

    The study of tree root systems is central to understanding forest ecosystem carbon and nutrient cycles, nutrient and water uptake, C allocation patterns by trees, soil microbial populations, adaptation of trees to stress, soil organic matter production, etc. Methodological probl...

  18. Effect of root temperature on the uptake and metabolism of anions by the root system of Zea mays L. I. Uptake of sulphate by resistant and non-resistant plants

    Energy Technology Data Exchange (ETDEWEB)

    Holobrada, M; Mistrik, I; Kolek, J [Institute of Experimental Biology and Ecology of the Slovak Academy of Sciences, Bratislava (Czechoslovakia)

    1980-01-01

    The effect of root temperature upon the uptake of /sup 35/S-sulfate by intact 21 days old maize roots was discussed. The plant roots grown at 20 degC were cooled in steps down to 15 degC or 5 degC. The rate of /sup 35/S uptake was studied both in the whole root system and separately in the individual roots (primary seminal root, seminal adventitious roots and nodal roots). Differences were ascertained at lower uptakes by various root samples from resistant and nonresistant maize cultivars.

  19. Association of orthodontic force system and root resorption: A systematic review.

    Science.gov (United States)

    Roscoe, Marina G; Meira, Josete B C; Cattaneo, Paolo M

    2015-05-01

    In this systematic review, we assessed the literature to determine which evidence level supports the association of orthodontic force system and root resorption. PubMed, Cochrane, and Embase databases were searched with no restrictions on year, publication status, or language. Selection criteria included human studies conducted with fixed orthodontic appliances or aligners, with at least 10 patients and the force system well described. A total of 259 articles were retrieved in the initial search. After the review process, 21 full-text articles met the inclusion criteria. Sample sizes ranged from 10 to 73 patients. Most articles were classified as having high evidence levels and low risks of bias. Although a meta-analysis was not performed, from the available literature, it seems that positive correlations exist between increased force levels and increased root resorption, as well as between increased treatment time and increased root resorption. Moreover, a pause in tooth movement seems to be beneficial in reducing root resorption because it allows the resorbed cementum to heal. The absence of a control group, selection criteria of patients, and adequate examinations before and after treatment are the most common methodology flaws. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  20. Uptake and localisation of lead in the root system of Brassica juncea

    International Nuclear Information System (INIS)

    Meyers, Donald E.R.; Auchterlonie, Graeme J.; Webb, Richard I.; Wood, Barry

    2008-01-01

    The uptake and distribution of Pb sequestered by hydroponically grown (14 days growth) Brassica juncea (3 days exposure; Pb activities 3.2, 32 and 217 μM) was investigated. Lead uptake was restricted largely to root tissue. Examination using scanning transmission electron microscopy-energy dispersive spectroscopy revealed substantial and predominantly intracellular uptake at the root tip. Endocytosis of Pb at the plasma membrane was not observed. A membrane transport protein may therefore be involved. In contrast, endocytosis of Pb into a subset of vacuoles was observed, resulting in the formation of dense Pb aggregates. Sparse and predominantly extracellular uptake occurred at some distance from the root tip. X-ray photoelectron spectroscopy confirmed that the Pb concentration was greater in root tips. Heavy metal rhizofiltration using B. juncea might therefore be improved by breeding plants with profusely branching roots. Uptake enhancement using genetic engineering techniques would benefit from investigation of plasma membrane transport mechanisms. - The sites of Pb sequestration within the root system of hydroponically grown Brassica juncea were identified

  1. Effect of different irrigation systems on root growth of maize and cowpea plants in sandy soil

    Directory of Open Access Journals (Sweden)

    Noha A. Mahgoub

    2017-10-01

    Full Text Available A field experiment was conducted at the Experimental Farm, Faculty of Agriculture, Suez Canal University to study the influence of different irrigation systems on root length density and specific root length of maize and cowpea plants cultivated in sandy soil. Three irrigation systems (Surface, drip and sprinkler irrigation were used in this study. The NPK fertilizers were applied as recommended doses for maize and cowpea. Root samples were collected from the soil profile below one plant (maize and cowpea which was irrigated by the three irrigation systems by using an iron box (30 cm× 20 cm which is divided into 24 small boxes each box is (5× 5 × 5 cm. At surface irrigation, root length density of cowpea reached to soil depth 30-40cm with lateral distances 5-10 cm and 15-20 cm. Vertical distribution of root length density of maize was increased with soil depth till 20-25 cm, and then it decreased till soil depth 35-40cm. Under drip irrigation, root length density of cowpea increased horizontally from 0-5cm to 10-15cm then it decreased till soil depth 25-30 cm and below this depth root length density disappeared. For the root length density and specific root length of maize under drip irrigation, the data showed that root length density and specific root length decreased with increasing in soil depth. The root length density of cowpea under sprinkler irrigation at 0-5cm disappeared from horizontal distance at 25-30 cm. The data showed that root length density of maize under sprinkler irrigation was higher at the soil top layers 0-5 cm and 5-10 cm than other layers from 10-40 cm.

  2. Segregation and Alteration of Phenolic and Aliphatic Components of Root and Leaf Litter by Detritivores and Microbes

    Science.gov (United States)

    Filley, T. R.; Altmann, J.; Szlavecz, K. A.; Kalbitz, K.; Gamblin, D.; Nierop, K.

    2012-12-01

    The physical and microbial transformation of plant detritus in the litter layer and soil is accompanied by chemical separation of progressively soluble fractions and their movement into the rhizosphere driving subsequent soil processes. We investigated the combined action of specific detritivores, microbial decay, and leaching on the chemical separation of plant aromatic and aliphatic components from root, wood, and leaf tissue using 13C-TMAH thermochemolysis. This method enabled the simultaneous analysis of hydrolyzable tannin and lignin fragments, substituted fatty acids, and condensed tannin composition and revealed process-specific chemical transformations to plant secondary compounds. Long-term incubation and field sampling demonstrated how plant residues are progressively leached of the water soluble, oxidized fragments generated through decay. The residues appeared only slightly altered, in the case of brown rot wood, or enriched in aliphatic fragments, in the case of leaf and root tissue. Water extractable fractions were always selectively dominated by polyphenolics, either as demethylated lignin or tannins, and nearly devoid of aliphatic materials, despite high concentrations in the starting materials. Additionally, for plant materials with high tannin contents, such as pine needles, consumption and passage through some arthropod guts revealed what appeared to be microbially-mediated methylation of phenols, and a loss of tannins in leachates. These findings are indications for an in-situ phenol detoxification mechanism. This research provides important information regarding the links between biochemical decay and the chemical nature of organic matter removed and remaining in the soil profile.

  3. Advanced type 1 diabetes is associated with ASIC alterations in mouse lower thoracic dorsal root ganglia neurons.

    Science.gov (United States)

    Radu, Beatrice Mihaela; Dumitrescu, Diana Ionela; Marin, Adela; Banciu, Daniel Dumitru; Iancu, Adina Daniela; Selescu, Tudor; Radu, Mihai

    2014-01-01

    Acid-sensing ion channels (ASICs) from dorsal root ganglia (DRG) neurons are proton sensors during ischemia and inflammation. Little is known about their role in type 1 diabetes (T1D). Our study was focused on ASICs alterations determined by advanced T1D status. Primary neuronal cultures were obtained from lower (T9-T12) thoracic DRG neurons from Balb/c and TCR-HA(+/-)/Ins-HA(+/-) diabetic male mice (16 weeks of age). Patch-clamp recordings indicate a change in the number of small DRG neurons presenting different ASIC-type currents. Multiple molecular sites of ASICs are distinctly affected in T1D, probably due to particular steric constraints for glycans accessibility to the active site: (i) ASIC1 current inactivates faster, while ASIC2 is slower; (ii) PcTx1 partly reverts diabetes effects against ASIC1- and ASIC2-inactivations; (iii) APETx2 maintains unaltered potency against ASIC3 current amplitude, but slows ASIC3 inactivation. Immunofluorescence indicates opposite regulation of different ASIC transcripts while qRT-PCR shows that ASIC mRNA ranking (ASIC2 > ASIC1 > ASIC3) remains unaltered. In conclusion, our study has identified biochemical and biophysical ASIC changes in lower thoracic DRG neurons due to advanced T1D. As hypoalgesia is present in advanced T1D, ASICs alterations might be the cause or the consequence of diabetic insensate neuropathy.

  4. Responses of root architecture development to low phosphorus availability: a review.

    Science.gov (United States)

    Niu, Yao Fang; Chai, Ru Shan; Jin, Gu Lei; Wang, Huan; Tang, Cai Xian; Zhang, Yong Song

    2013-07-01

    Phosphorus (P) is an essential element for plant growth and development but it is often a limiting nutrient in soils. Hence, P acquisition from soil by plant roots is a subject of considerable interest in agriculture, ecology and plant root biology. Root architecture, with its shape and structured development, can be considered as an evolutionary response to scarcity of resources. This review discusses the significance of root architecture development in response to low P availability and its beneficial effects on alleviation of P stress. It also focuses on recent progress in unravelling cellular, physiological and molecular mechanisms in root developmental adaptation to P starvation. The progress in a more detailed understanding of these mechanisms might be used for developing strategies that build upon the observed explorative behaviour of plant roots. The role of root architecture in alleviation of P stress is well documented. However, this paper describes how plants adjust their root architecture to low-P conditions through inhibition of primary root growth, promotion of lateral root growth, enhancement of root hair development and cluster root formation, which all promote P acquisition by plants. The mechanisms for activating alterations in root architecture in response to P deprivation depend on changes in the localized P concentration, and transport of or sensitivity to growth regulators such as sugars, auxins, ethylene, cytokinins, nitric oxide (NO), reactive oxygen species (ROS) and abscisic acid (ABA). In the process, many genes are activated, which in turn trigger changes in molecular, physiological and cellular processes. As a result, root architecture is modified, allowing plants to adapt effectively to the low-P environment. This review provides a framework for understanding how P deficiency alters root architecture, with a focus on integrated physiological and molecular signalling.

  5. Responses of root architecture development to low phosphorus availability: a review

    Science.gov (United States)

    Niu, Yao Fang; Chai, Ru Shan; Jin, Gu Lei; Wang, Huan; Tang, Cai Xian; Zhang, Yong Song

    2013-01-01

    Background Phosphorus (P) is an essential element for plant growth and development but it is often a limiting nutrient in soils. Hence, P acquisition from soil by plant roots is a subject of considerable interest in agriculture, ecology and plant root biology. Root architecture, with its shape and structured development, can be considered as an evolutionary response to scarcity of resources. Scope This review discusses the significance of root architecture development in response to low P availability and its beneficial effects on alleviation of P stress. It also focuses on recent progress in unravelling cellular, physiological and molecular mechanisms in root developmental adaptation to P starvation. The progress in a more detailed understanding of these mechanisms might be used for developing strategies that build upon the observed explorative behaviour of plant roots. Conclusions The role of root architecture in alleviation of P stress is well documented. However, this paper describes how plants adjust their root architecture to low-P conditions through inhibition of primary root growth, promotion of lateral root growth, enhancement of root hair development and cluster root formation, which all promote P acquisition by plants. The mechanisms for activating alterations in root architecture in response to P deprivation depend on changes in the localized P concentration, and transport of or sensitivity to growth regulators such as sugars, auxins, ethylene, cytokinins, nitric oxide (NO), reactive oxygen species (ROS) and abscisic acid (ABA). In the process, many genes are activated, which in turn trigger changes in molecular, physiological and cellular processes. As a result, root architecture is modified, allowing plants to adapt effectively to the low-P environment. This review provides a framework for understanding how P deficiency alters root architecture, with a focus on integrated physiological and molecular signalling. PMID:23267006

  6. Systemic dystrophic alterations of skeleton

    International Nuclear Information System (INIS)

    Zedgenidze, G.A.; Kishkovskij, A.N.; Elashov, Yu.G.

    1984-01-01

    A roentgenologic picture of dystrophic alterations of bones following hard, acute and chronic infections diseases, distinct disorders of vitanium balance, diseases of endocrine system, disorder of metabolism and diet, long-term exogenous intoxications including medicinal is given. Distinct dystrophic disorders are characterized both by quantitative and qualitative deviations in physiological change of bones

  7. Grass Rooting the System

    Science.gov (United States)

    Perlman, Janice E.

    1976-01-01

    Suggests a taxonomy of the grass roots movement and gives a general descriptive over view of the 60 groups studied with respect to origin, constituency, size, funding, issues, and ideology. (Author/AM)

  8. Characterization of Pearl Millet Root Architecture and Anatomy Reveals Three Types of Lateral Roots

    Science.gov (United States)

    Passot, Sixtine; Gnacko, Fatoumata; Moukouanga, Daniel; Lucas, Mikaël; Guyomarc’h, Soazig; Ortega, Beatriz Moreno; Atkinson, Jonathan A.; Belko, Marème N.; Bennett, Malcolm J.; Gantet, Pascal; Wells, Darren M.; Guédon, Yann; Vigouroux, Yves; Verdeil, Jean-Luc; Muller, Bertrand; Laplaze, Laurent

    2016-01-01

    Pearl millet plays an important role for food security in arid regions of Africa and India. Nevertheless, it is considered an orphan crop as it lags far behind other cereals in terms of genetic improvement efforts. Breeding pearl millet varieties with improved root traits promises to deliver benefits in water and nutrient acquisition. Here, we characterize early pearl millet root system development using several different root phenotyping approaches that include rhizotrons and microCT. We report that early stage pearl millet root system development is characterized by a fast growing primary root that quickly colonizes deeper soil horizons. We also describe root anatomical studies that revealed three distinct types of lateral roots that form on both primary roots and crown roots. Finally, we detected significant variation for two root architectural traits, primary root lenght and lateral root density, in pearl millet inbred lines. This study provides the basis for subsequent genetic experiments to identify loci associated with interesting early root development traits in this important cereal. PMID:27379124

  9. 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

  10. Salicylic acid prevents Trichoderma harzianum from entering the vascular system of roots.

    Science.gov (United States)

    Alonso-Ramírez, Ana; Poveda, Jorge; Martín, Ignacio; Hermosa, Rosa; Monte, Enrique; Nicolás, Carlos

    2014-10-01

    Trichoderma is a soil-borne fungal genus that includes species with a significant impact on agriculture and industrial processes. Some Trichoderma strains exert beneficial effects in plants through root colonization, although little is known about how this interaction takes place. To better understand this process, the root colonization of wild-type Arabidopsis and the salicylic acid (SA)-impaired mutant sid2 by a green fluorescent protein (GFP)-marked Trichoderma harzianum strain was followed under confocal microscopy. Trichoderma harzianum GFP22 was able to penetrate the vascular tissue of the sid2 mutant because of the absence of callose deposition in the cell wall of root cells. In addition, a higher colonization of sid2 roots by GFP22 compared with that in Arabidopsis wild-type roots was detected by real-time polymerase chain reaction. These results, together with differences in the expression levels of plant defence genes in the roots of both interactions, support a key role for SA in Trichoderma early root colonization stages. We observed that, without the support of SA, plants were unable to prevent the arrival of the fungus in the vascular system and its spread into aerial parts, leading to later collapse. © 2014 BSPP AND JOHN WILEY & SONS LTD.

  11. Rapid phenotyping of crop root systems in undisturbed field soils using X-ray computed tomography.

    Science.gov (United States)

    Pfeifer, Johannes; Kirchgessner, Norbert; Colombi, Tino; Walter, Achim

    2015-01-01

    X-ray computed tomography (CT) has become a powerful tool for root phenotyping. Compared to rather classical, destructive methods, CT encompasses various advantages. In pot experiments the growth and development of the same individual root can be followed over time and in addition the unaltered configuration of the 3D root system architecture (RSA) interacting with a real field soil matrix can be studied. Yet, the throughput, which is essential for a more widespread application of CT for basic research or breeding programs, suffers from the bottleneck of rapid and standardized segmentation methods to extract root structures. Using available methods, root segmentation is done to a large extent manually, as it requires a lot of interactive parameter optimization and interpretation and therefore needs a lot of time. Based on commercially available software, this paper presents a protocol that is faster, more standardized and more versatile compared to existing segmentation methods, particularly if used to analyse field samples collected in situ. To the knowledge of the authors this is the first study approaching to develop a comprehensive segmentation method suitable for comparatively large columns sampled in situ which contain complex, not necessarily connected root systems from multiple plants grown in undisturbed field soil. Root systems from several crops were sampled in situ and CT-volumes determined with the presented method were compared to root dry matter of washed root samples. A highly significant (P < 0.01) and strong correlation (R(2) = 0.84) was found, demonstrating the value of the presented method in the context of field research. Subsequent to segmentation, a method for the measurement of root thickness distribution has been used. Root thickness is a central RSA trait for various physiological research questions such as root growth in compacted soil or under oxygen deficient soil conditions, but hardly assessable in high throughput until today, due

  12. Traits and selection strategies to improve root systems and water uptake in water-limited wheat crops.

    Science.gov (United States)

    Wasson, A P; Richards, R A; Chatrath, R; Misra, S C; Prasad, S V Sai; Rebetzke, G J; Kirkegaard, J A; Christopher, J; Watt, M

    2012-05-01

    Wheat yields globally will depend increasingly on good management to conserve rainfall and new varieties that use water efficiently for grain production. Here we propose an approach for developing new varieties to make better use of deep stored water. We focus on water-limited wheat production in the summer-dominant rainfall regions of India and Australia, but the approach is generally applicable to other environments and root-based constraints. Use of stored deep water is valuable because it is more predictable than variable in-season rainfall and can be measured prior to sowing. Further, this moisture is converted into grain with twice the efficiently of in-season rainfall since it is taken up later in crop growth during the grain-filling period when the roots reach deeper layers. We propose that wheat varieties with a deeper root system, a redistribution of branch root density from the surface to depth, and with greater radial hydraulic conductivity at depth would have higher yields in rainfed systems where crops rely on deep water for grain fill. Developing selection systems for mature root system traits is challenging as there are limited high-throughput phenotyping methods for roots in the field, and there is a risk that traits selected in the lab on young plants will not translate into mature root system traits in the field. We give an example of a breeding programme that combines laboratory and field phenotyping with proof of concept evaluation of the trait at the beginning of the selection programme. This would greatly enhance confidence in a high-throughput laboratory or field screen, and avoid investment in screens without yield value. This approach requires careful selection of field sites and years that allow expression of deep roots and increased yield. It also requires careful selection and crossing of germplasm to allow comparison of root expression among genotypes that are similar for other traits, especially flowering time and disease and toxicity

  13. Split-root systems applied to the study of the legume-rhizobial symbiosis: what have we learned?

    Science.gov (United States)

    Larrainzar, Estíbaliz; Gil-Quintana, Erena; Arrese-Igor, Cesar; González, Esther M; Marino, Daniel

    2014-12-01

    Split-root system (SRS) approaches allow the differential treatment of separate and independent root systems, while sharing a common aerial part. As such, SRS is a useful tool for the discrimination of systemic (shoot origin) versus local (root/nodule origin) regulation mechanisms. This type of approach is particularly useful when studying the complex regulatory mechanisms governing the symbiosis established between legumes and Rhizobium bacteria. The current work provides an overview of the main insights gained from the application of SRS approaches to understand how nodule number (nodulation autoregulation) and nitrogen fixation are controlled both under non-stressful conditions and in response to a variety of stresses. Nodule number appears to be mainly controlled at the systemic level through a signal which is produced by nodule/root tissue, translocated to the shoot, and transmitted back to the root system, involving shoot Leu-rich repeat receptor-like kinases. In contrast, both local and systemic mechanisms have been shown to operate for the regulation of nitrogenase activity in nodules. Under drought and heavy metal stress, the regulation is mostly local, whereas the application of exogenous nitrogen seems to exert a regulation of nitrogen fixation both at the local and systemic levels. © 2014 Institute of Botany, Chinese Academy of Sciences.

  14. DigR: a generic model and its open source simulation software to mimic three-dimensional root-system architecture diversity.

    Science.gov (United States)

    Barczi, Jean-François; Rey, Hervé; Griffon, Sébastien; Jourdan, Christophe

    2018-04-18

    Many studies exist in the literature dealing with mathematical representations of root systems, categorized, for example, as pure structure description, partial derivative equations or functional-structural plant models. However, in these studies, root architecture modelling has seldom been carried out at the organ level with the inclusion of environmental influences that can be integrated into a whole plant characterization. We have conducted a multidisciplinary study on root systems including field observations, architectural analysis, and formal and mathematical modelling. This integrative and coherent approach leads to a generic model (DigR) and its software simulator. Architecture analysis applied to root systems helps at root type classification and architectural unit design for each species. Roots belonging to a particular type share dynamic and morphological characteristics which consist of topological and geometric features. The DigR simulator is integrated into the Xplo environment, with a user interface to input parameter values and make output ready for dynamic 3-D visualization, statistical analysis and saving to standard formats. DigR is simulated in a quasi-parallel computing algorithm and may be used either as a standalone tool or integrated into other simulation platforms. The software is open-source and free to download at http://amapstudio.cirad.fr/soft/xplo/download. DigR is based on three key points: (1) a root-system architectural analysis, (2) root type classification and modelling and (3) a restricted set of 23 root type parameters with flexible values indexed in terms of root position. Genericity and botanical accuracy of the model is demonstrated for growth, branching, mortality and reiteration processes, and for different root architectures. Plugin examples demonstrate the model's versatility at simulating plastic responses to environmental constraints. Outputs of the model include diverse root system structures such as tap-root

  15. Root interactions in a maize/soybean intercropping system control soybean soil-borne disease, red crown rot.

    Directory of Open Access Journals (Sweden)

    Xiang Gao

    Full Text Available BACKGROUND: Within-field multiple crop species intercropping is well documented and used for disease control, but the underlying mechanisms are still unclear. As roots are the primary organ for perceiving signals in the soil from neighboring plants, root behavior may play an important role in soil-borne disease control. PRINCIPAL FINDINGS: In two years of field experiments, maize/soybean intercropping suppressed the occurrence of soybean red crown rot, a severe soil-borne disease caused by Cylindrocladium parasiticum (C. parasiticum. The suppressive effects decreased with increasing distance between intercropped plants under both low P and high P supply, suggesting that root interactions play a significant role independent of nutrient status. Further detailed quantitative studies revealed that the diversity and intensity of root interactions altered the expression of important soybean PR genes, as well as, the activity of corresponding enzymes in both P treatments. Furthermore, 5 phenolic acids were detected in root exudates of maize/soybean intercropped plants. Among these phenolic acids, cinnamic acid was released in significantly greater concentrations when intercropped maize with soybean compared to either crop grown in monoculture, and this spike in cinnamic acid was found dramatically constrain C. parasiticum growth in vitro. CONCLUSIONS: To the best of our knowledge, this study is the first report to demonstrate that intercropping with maize can promote resistance in soybean to red crown rot in a root-dependent manner. This supports the point that intercropping may be an efficient ecological strategy to control soil-borne plant disease and should be incorporated in sustainable agricultural management practices.

  16. Two-dimensional Root Phenotyping System Based on Root Growth on Black Filter Paper and Recirculation Micro-irrigation

    Czech Academy of Sciences Publication Activity Database

    Rattanapichai, W.; Klem, Karel

    2016-01-01

    Roč. 52, č. 2 (2016), s. 64-70 ISSN 1212-1975 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : image analysis * nutrient deficiency * root system architecture * spring barley Subject RIV: EH - Ecology, Behaviour Impact factor: 0.532, year: 2016

  17. A test system to quantify inoculum in runoff from Phytophthora ramorum-infected plant roots

    Science.gov (United States)

    Nina. Shishkoff

    2010-01-01

    Foliar hosts of Phytophthora ramorum are often susceptible to root infection, but the epidemiological significance of such infections is unknown. We used a standardized test system to study inoculum in runoff from root-infected Viburnum tinus cuttings.

  18. Root morphology and mycorrhizal symbioses together shape nutrient foraging strategies of temperate trees.

    Science.gov (United States)

    Chen, Weile; Koide, Roger T; Adams, Thomas S; DeForest, Jared L; Cheng, Lei; Eissenstat, David M

    2016-08-02

    Photosynthesis by leaves and acquisition of water and minerals by roots are required for plant growth, which is a key component of many ecosystem functions. Although the role of leaf functional traits in photosynthesis is generally well understood, the relationship of root functional traits to nutrient uptake is not. In particular, predictions of nutrient acquisition strategies from specific root traits are often vague. Roots of nearly all plants cooperate with mycorrhizal fungi in nutrient acquisition. Most tree species form symbioses with either arbuscular mycorrhizal (AM) or ectomycorrhizal (EM) fungi. Nutrients are distributed heterogeneously in the soil, and nutrient-rich "hotspots" can be a key source for plants. Thus, predicting the foraging strategies that enable mycorrhizal root systems to exploit these hotspots can be critical to the understanding of plant nutrition and ecosystem carbon and nutrient cycling. Here, we show that in 13 sympatric temperate tree species, when nutrient availability is patchy, thinner root species alter their foraging to exploit patches, whereas thicker root species do not. Moreover, there appear to be two distinct pathways by which thinner root tree species enhance foraging in nutrient-rich patches: AM trees produce more roots, whereas EM trees produce more mycorrhizal fungal hyphae. Our results indicate that strategies of nutrient foraging are complementary among tree species with contrasting mycorrhiza types and root morphologies, and that predictable relationships between below-ground traits and nutrient acquisition emerge only when both roots and mycorrhizal fungi are considered together.

  19. 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.

  20. Microgravity effects on water supply and substrate properties in porous matrix root support systems

    Science.gov (United States)

    Bingham, G. E.; Jones, S. B.; Or, D.; Podolski, I. G.; Levinskikh, M. A.; Sytchov, V. N.; Ivanova, T.; Kostov, P.; Sapunova, S.; Dandolov, I.; hide

    2000-01-01

    The control of water content and water movement in granular substrate-based plant root systems in microgravity is a complex problem. Improper water and oxygen delivery to plant roots has delayed studies of the effects of microgravity on plant development and the use of plants in physical and mental life support systems. Our international effort (USA, Russia and Bulgaria) has upgraded the plant growth facilities on the Mir Orbital Station (OS) and used them to study the full life cycle of plants. The Bulgarian-Russian-developed Svet Space Greenhouse (SG) system was upgraded on the Mir OS in 1996. The US developed Gas Exchange Measurement System (GEMS) greatly extends the range of environmental parameters monitored. The Svet-GEMS complex was used to grow a fully developed wheat crop during 1996. The growth rate and development of these plants compared well with earth grown plants indicating that the root zone water and oxygen stresses that have limited plant development in previous long-duration experiments have been overcome. However, management of the root environment during this experiment involved several significant changes in control settings as the relationship between the water delivery system, water status sensors, and the substrate changed during the growth cycles. c 2001 Published by Elsevier Science Ltd. All rights reserved.

  1. Cadmium-induced functional and ultrastructural alterations in roots of two transgenic cotton cultivars

    International Nuclear Information System (INIS)

    Daud, M.K.; Sun, Yuqiang; Dawood, M.; Hayat, Y.; Variath, M.T.; Wu Yuxiang; Raziuddin; Mishkat, Ullah; Salahuddin; Najeeb, Ullah; Zhu, Shuijin

    2009-01-01

    The toxic effect of cadmium (Cd) at increasing concentrations was studied with special attention being given to the root morphological and ultrastructural changes in two transgenic cotton cultivars viz. BR001 and GK30 and their wild relative viz. Coker 312. In comparison to their respective controls, low concentration (10 and 100 μM) of Cd greatly stimulated seed germination, while it was inhibited by highest concentration of Cd (1000 μM) in case of two transgenic cultivars. However, in Coker 312 the seed germination percentage progressively decreased over the control at all Cd levels. Various physiological and morphological parameters of the root and whole plant in both transgenic cotton cultivars and their relative wild cotton genotype respond differently towards the Cd toxicity. Bioavailability of Cd was concentration-dependent where seedling root captured more Cd as compared to shoot. BR001 accumulated more Cd followed by GK30, while Coker 312 was less Cd accumulator. The ultrastructural modifications in the root tip cells of both the transgenic cotton cultivars and their wild relative were also dose-dependent. With the increase in Cd levels, the fine structures of their root cells also invariably changed. Increase in plasmolysis of the plasma membrane, greater number of nucleoli and vacuoles and enlarged vacuoles could be observed in both transgenic cotton cultivars. In comparison to them, Coker 312 showed relatively well developed ultrastructures of the root tips except enlarged vacuoles and greater number of mitochondria. Moreover, the accumulation of Cd in the form of electron dense granules and crystals both in vacuoles and attached to cell walls were visible in both transgenic cotton cultivars and their wild relative. These results suggest that both transgenic cotton cultivars and their wild relative cotton genotype responded positively towards Cd stress at seedling stage, the internal Cd-detoxification might be through apoplastic and symplastic binding

  2. Cadmium-induced functional and ultrastructural alterations in roots of two transgenic cotton cultivars

    Energy Technology Data Exchange (ETDEWEB)

    Daud, M.K.; Sun, Yuqiang; Dawood, M. [Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310029 (China); Hayat, Y. [Institute of Bioinformatics, Zhejiang University, Hangzhou 310029 (China); Variath, M.T.; Wu Yuxiang [Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310029 (China); Raziuddin [Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310029 (China); Plant Breeding and Genetics Department, NWFP Agricultural University Peshawar, Peshawar (Pakistan); Mishkat, Ullah [Zoological Sciences Division, Pakistan Museum of Natural History, Garden Avenue, Shakarparian, Islamabad 44000 (Pakistan); Salahuddin [District Agriculture Extension Offices, Bannu Road, Dera Ismail Khan (NWFP) (Pakistan); Najeeb, Ullah [Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310029 (China); Zhu, Shuijin [Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310029 (China)], E-mail: shjzhu@zju.edu.cn

    2009-01-15

    The toxic effect of cadmium (Cd) at increasing concentrations was studied with special attention being given to the root morphological and ultrastructural changes in two transgenic cotton cultivars viz. BR001 and GK30 and their wild relative viz. Coker 312. In comparison to their respective controls, low concentration (10 and 100 {mu}M) of Cd greatly stimulated seed germination, while it was inhibited by highest concentration of Cd (1000 {mu}M) in case of two transgenic cultivars. However, in Coker 312 the seed germination percentage progressively decreased over the control at all Cd levels. Various physiological and morphological parameters of the root and whole plant in both transgenic cotton cultivars and their relative wild cotton genotype respond differently towards the Cd toxicity. Bioavailability of Cd was concentration-dependent where seedling root captured more Cd as compared to shoot. BR001 accumulated more Cd followed by GK30, while Coker 312 was less Cd accumulator. The ultrastructural modifications in the root tip cells of both the transgenic cotton cultivars and their wild relative were also dose-dependent. With the increase in Cd levels, the fine structures of their root cells also invariably changed. Increase in plasmolysis of the plasma membrane, greater number of nucleoli and vacuoles and enlarged vacuoles could be observed in both transgenic cotton cultivars. In comparison to them, Coker 312 showed relatively well developed ultrastructures of the root tips except enlarged vacuoles and greater number of mitochondria. Moreover, the accumulation of Cd in the form of electron dense granules and crystals both in vacuoles and attached to cell walls were visible in both transgenic cotton cultivars and their wild relative. These results suggest that both transgenic cotton cultivars and their wild relative cotton genotype responded positively towards Cd stress at seedling stage, the internal Cd-detoxification might be through apoplastic and symplastic

  3. Vertical Root Fracture initiation in curved roots after root canal preparation: A dentinal micro-crack analysis with LED transillumination.

    Science.gov (United States)

    Miguéns-Vila, Ramón; Martín-Biedma, Benjamín; Varela-Patiño, Purificación; Ruíz-Piñón, Manuel; Castelo-Baz, Pablo

    2017-10-01

    One of the causative factors of root defects is the increased friction produced by rotary instrumentation. A high canal curvature may increase stress, making the tooth more susceptible to dentinal cracks. The purpose of this study was to evaluate dentinal micro-crack formation with the ProTaper NEXT and ProTaper Universal systems using LED transillumination, and to analyze the micro-crack generated at the point of maximum canal curvature. 60 human mandibular premolars with curvatures between 30-49° and radii between 2-4 mm were used. The root canals were instrumented using the Protaper Universal® and Protaper NEXT® systems, with the aid of the Proglider® system. The obtained samples were sectioned transversely before subsequent analysis with LED transillumination at 2 mm and 8 mm from the apex and at the point of maximum canal curvature. Defects were scored: 0 for no defects; and 1 for micro-cracks. Root defects were not observed in the control group. The ProTaper NEXT system caused fewer defects (16.7%) than the ProTaper Universal system (40%) ( P Universal system caused significantly more micro-cracks at the point of maximum canal curvature than the ProTaper NEXT system ( P Universal system. A higher prevalence of defects was found at the point of maximum curvature in the ProTaper Universal group. Key words: Curved root, Micro-crack, point of maximum canal curvature, ProTaper NEXT, ProTaper Universal, Vertical root fracture.

  4. Complementarity in nutrient foraging strategies of absorptive fine roots and arbuscular mycorrhizal fungi across 14 coexisting subtropical tree species.

    Science.gov (United States)

    Liu, Bitao; Li, Hongbo; Zhu, Biao; Koide, Roger T; Eissenstat, David M; Guo, Dali

    2015-10-01

    In most cases, both roots and mycorrhizal fungi are needed for plant nutrient foraging. Frequently, the colonization of roots by arbuscular mycorrhizal (AM) fungi seems to be greater in species with thick and sparsely branched roots than in species with thin and densely branched roots. Yet, whether a complementarity exists between roots and mycorrhizal fungi across these two types of root system remains unclear. We measured traits related to nutrient foraging (root morphology, architecture and proliferation, AM colonization and extramatrical hyphal length) across 14 coexisting AM subtropical tree species following root pruning and nutrient addition treatments. After root pruning, species with thinner roots showed more root growth, but lower mycorrhizal colonization, than species with thicker roots. Under multi-nutrient (NPK) addition, root growth increased, but mycorrhizal colonization decreased significantly, whereas no significant changes were found under nitrogen or phosphate additions. Moreover, root length proliferation was mainly achieved by altering root architecture, but not root morphology. Thin-root species seem to forage nutrients mainly via roots, whereas thick-root species rely more on mycorrhizal fungi. In addition, the reliance on mycorrhizal fungi was reduced by nutrient additions across all species. These findings highlight complementary strategies for nutrient foraging across coexisting species with contrasting root traits. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  5. Arsenic-induced stress activates sulfur metabolism in different organs of garlic (Allium sativum L.) plants accompanied by a general decline of the NADPH-generating systems in roots.

    Science.gov (United States)

    Ruíz-Torres, Carmelo; Feriche-Linares, Rafael; Rodríguez-Ruíz, Marta; Palma, José M; Corpas, Francisco J

    2017-04-01

    Arsenic (As) contamination is a major environmental problem which affects most living organisms from plants to animals. This metalloid poses a health risk for humans through its accumulation in crops and water. Using garlic (Allium sativum L.) plants as model crop exposed to 200μM arsenate, a comparative study among their main organs (roots and shoots) was made. The analysis of arsenic, glutathione (GSH), phytochelatins (PCs) and lipid peroxidation contents with the activities of antioxidant enzymes (catalase, superoxide dismutase, ascorbate-glutathione cycle), and the main components of the NADPH-generating system, including glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphogluconate dehydrogenase (6PGDH), NADP-malic enzyme (NADP-ME) and NADP-isocitrate dehydrogenase (NADP-ICDH) was carried out. Data showed a correlation among arsenic accumulation in the different organs, PCs content and the antioxidative response, with a general decline of the NADPH-generating systems in roots. Overall, our results demonstrate that there are clear connections between arsenic uptake, increase of their As-chelating capacity in roots and a decline of antioxidative enzyme activities (catalase and the ascorbate peroxidase) whose alteration provoked As-induced oxidative stress. Thus, the data suggest that roots act as barrier of arsenic mediated by a prominent sulfur metabolism which is characterized by the biosynthesis of high amount of PCs. Copyright © 2017 Elsevier GmbH. All rights reserved.

  6. Involvement of abscisic acid in regulating antioxidative defense systems and IAA-oxidase activity and improving adventitious rooting in mung bean [Vigna radiata (L.) Wilczek] seedlings under cadmium stress.

    Science.gov (United States)

    Li, Shi-Weng; Leng, Yan; Feng, Lin; Zeng, Xiao-Ying

    2014-01-01

    In vitro experiments were conducted to investigate the effects of abscisic acid (ABA) and Cd on antioxidative defense systems and indole-3-acetic acid (IAA) oxidase during adventitious rooting in mung bean [Vigna radiata (L.) Wilczek] seedlings. The exogenous ABA significantly enhanced the number and fresh weight of the adventitious roots. CdCl2 strongly inhibited adventitious rooting. Pretreatment with 10 μM ABA clearly alleviated the inhibitory effect of Cd on rooting. ABA significantly reduced superoxide dismutase (SOD), ascorbate peroxidase (APX), peroxidase (POD), and catalase (CAT) activities, as well as the levels of glutathione (GSH) and ascorbic acid (ASA) during adventitious rooting. ABA strongly increased IAA-oxidase activity during the induction (0-12 h) and expression (after 48 h) phases and increased the phenols levels. Cd treatment significantly reduced the activities of SOD, APX, POD, and IAA oxidase, as well as GSH level. Cd strongly increased ASA levels. ABA pretreatment counteracted Cd-induced alterations of certain antioxidants and antioxidative enzymes, e.g., remarkably rescued APX and POD activities, reduced the elevated SOD and CAT activities and ASA levels, and recovered the reduced GSH levels, caused by Cd stress. Thus, the physiological effects of the combination of ABA and Cd treatments were opposite of those obtained with Cd treatment alone, suggesting that ABA involved in the regulation of antioxidative defense systems and the alleviation of wounding- and Cd-induced oxidative stress.

  7. Proliferation and ajmalicine biosynthesis of Catharanthus roseus (L). G. Don adventitious roots in self-built temporary immersion system

    Science.gov (United States)

    Phuc, Vo Thanh; Trung, Nguyen Minh; Thien, Huynh Tri; Tien, Le Thi Thuy

    2017-09-01

    Periwinkle (Catharanthus roseus (L.) G. Don) is a medicinal plant containing about 130 types of alkaloids that have important pharmacological effects. Ajmalicine in periwinkle root is an antihypertensive drug used in treatment of high blood pressure. Adventitious roots obtained from periwinkle leaves of in vitro shoots grew well in quarter-strength MS medium supplemented with 0.3 mg/l IBA and 20 g/l sucrose. Dark condition was more suitable for root growth than light. However, callus formation also took place in addition to the growth of adventitious roots. Temporary immersion system was applied in the culture of adventitious roots in order to reduce the callus growth rate formed in shake flask cultures. The highest growth index of roots was achieved using the system with 5-min immersion every 45 min (1.676 ± 0.041). The roots cultured in this system grew well without callus formation. Ajmalicine content was highest in the roots cultured with 5-min immersion every 180 min (950 μg/g dry weight).

  8. Evaluation of Root Canal Preparation Using Rotary System and Hand Instruments Assessed by Micro-Computed Tomography.

    Science.gov (United States)

    Stavileci, Miranda; Hoxha, Veton; Görduysus, Ömer; Tatar, Ilkan; Laperre, Kjell; Hostens, Jeroen; Küçükkaya, Selen; Muhaxheri, Edmond

    2015-06-20

    Complete mechanical preparation of the root canal system is rarely achieved. Therefore, the purpose of this study was to evaluate and compare the root canal shaping efficacy of ProTaper rotary files and standard stainless steel K-files using micro-computed tomography. Sixty extracted upper second premolars were selected and divided into 2 groups of 30 teeth each. Before preparation, all samples were scanned by micro-computed tomography. Thirty teeth were prepared with the ProTaper system and the other 30 with stainless steel files. After preparation, the untouched surface and root canal straightening were evaluated with micro-computed tomography. The percentage of untouched root canal surface was calculated in the coronal, middle, and apical parts of the canal. We also calculated straightening of the canal after root canal preparation. Results from the 2 groups were statistically compared using the Minitab statistical package. ProTaper rotary files left less untouched root canal surface compared with manual preparation in coronal, middle, and apical sector (p<0.001). Similarly, there was a statistically significant difference in root canal straightening after preparation between the techniques (p<0.001). Neither manual nor rotary techniques completely prepared the root canal, and both techniques caused slight straightening of the root canal.

  9. Evaluation of Root Canal Preparation Using Rotary System and Hand Instruments Assessed by Micro-Computed Tomography

    Science.gov (United States)

    Stavileci, Miranda; Hoxha, Veton; Görduysus, Ömer; Tatar, Ilkan; Laperre, Kjell; Hostens, Jeroen; Küçükkaya, Selen; Muhaxheri, Edmond

    2015-01-01

    Background Complete mechanical preparation of the root canal system is rarely achieved. Therefore, the purpose of this study was to evaluate and compare the root canal shaping efficacy of ProTaper rotary files and standard stainless steel K-files using micro-computed tomography. Material/Methods Sixty extracted upper second premolars were selected and divided into 2 groups of 30 teeth each. Before preparation, all samples were scanned by micro-computed tomography. Thirty teeth were prepared with the ProTaper system and the other 30 with stainless steel files. After preparation, the untouched surface and root canal straightening were evaluated with micro-computed tomography. The percentage of untouched root canal surface was calculated in the coronal, middle, and apical parts of the canal. We also calculated straightening of the canal after root canal preparation. Results from the 2 groups were statistically compared using the Minitab statistical package. Results ProTaper rotary files left less untouched root canal surface compared with manual preparation in coronal, middle, and apical sector (protary techniques completely prepared the root canal, and both techniques caused slight straightening of the root canal. PMID:26092929

  10. Auxins differentially regulate root system architecture and cell cycle protein levels in maize seedlings.

    Science.gov (United States)

    Martínez-de la Cruz, Enrique; García-Ramírez, Elpidio; Vázquez-Ramos, Jorge M; Reyes de la Cruz, Homero; López-Bucio, José

    2015-03-15

    Maize (Zea mays) root system architecture has a complex organization, with adventitious and lateral roots determining its overall absorptive capacity. To generate basic information about the earlier stages of root development, we compared the post-embryonic growth of maize seedlings germinated in water-embedded cotton beds with that of plants obtained from embryonic axes cultivated in liquid medium. In addition, the effect of four different auxins, namely indole-3-acetic acid (IAA), 1-naphthaleneacetic acid (NAA), indole-3-butyric acid (IBA) and 2,4-dichlorophenoxyacetic acid (2,4-D) on root architecture and levels of the heat shock protein HSP101 and the cell cycle proteins CKS1, CYCA1 and CDKA1 were analyzed. Our data show that during the first days after germination, maize seedlings develop several root types with a simultaneous and/or continuous growth. The post-embryonic root development started with the formation of the primary root (PR) and seminal scutellar roots (SSR) and then continued with the formation of adventitious crown roots (CR), brace roots (BR) and lateral roots (LR). Auxins affected root architecture in a dose-response fashion; whereas NAA and IBA mostly stimulated crown root formation, 2,4-D showed a strong repressing effect on growth. The levels of HSP101, CKS1, CYCA1 and CDKA in root and leaf tissues were differentially affected by auxins and interestingly, HSP101 registered an auxin-inducible and root specific expression pattern. Taken together, our results show the timing of early branching patterns of maize and indicate that auxins regulate root development likely through modulation of the HSP101 and cell cycle proteins. Copyright © 2014 Elsevier GmbH. All rights reserved.

  11. Overexpression of Arabidopsis plasmodesmata germin-like proteins disrupts root growth and development.

    Science.gov (United States)

    Ham, Byung-Kook; Li, Gang; Kang, Byung-Ho; Zeng, Fanchang; Lucas, William J

    2012-09-01

    In plants, a population of non-cell-autonomous proteins (NCAPs), including numerous transcription factors, move cell to cell through plasmodesmata (PD). In many cases, the intercellular trafficking of these NCAPs is regulated by their interaction with specific PD components. To gain further insight into the functions of this NCAP pathway, coimmunoprecipitation experiments were performed on a tobacco (Nicotiana tabacum) plasmodesmal-enriched cell wall protein preparation using as bait the NCAP, pumpkin (Cucurbita maxima) PHLOEM PROTEIN16 (Cm-PP16). A Cm-PP16 interaction partner, Nt-PLASMODESMAL GERMIN-LIKE PROTEIN1 (Nt-PDGLP1) was identified and shown to be a PD-located component. Arabidopsis thaliana putative orthologs, PDGLP1 and PDGLP2, were identified; expression studies indicated that, postgermination, these proteins were preferentially expressed in the root system. The PDGLP1 signal peptide was shown to function in localization to the PD by a novel mechanism involving the endoplasmic reticulum-Golgi secretory pathway. Overexpression of various tagged versions altered root meristem function, leading to reduced primary root but enhanced lateral root growth. This effect on root growth was corrected with an inability of these chimeric proteins to form stable PD-localized complexes. PDGLP1 and PDGLP2 appear to be involved in regulating primary root growth by controlling phloem-mediated allocation of resources between the primary and lateral root meristems.

  12. Fine root dynamics of mature European beech (Fagus sylvatica L.) as influenced by elevated ozone concentrations

    International Nuclear Information System (INIS)

    Mainiero, Raphael; Kazda, Marian; Haeberle, Karl-Heinz; Nikolova, Petia Simeonova; Matyssek, Rainer

    2009-01-01

    Fine root dynamics (diameter < 1 mm) in mature Fagus sylvatica, with the canopies exposed to ambient or twice-ambient ozone concentrations, were investigated throughout 2004. The focus was on the seasonal timing and extent of fine root dynamics (growth, mortality) in relation to the soil environment (water content, temperature). Under ambient ozone concentrations, a significant relationship was found between fine root turnover and soil environmental changes indicating accelerated fine root turnover under favourable soil conditions. In contrast, under elevated ozone, this relationship vanished as the result of an altered temporal pattern of fine root growth. Fine root survival and turnover rate did not differ significantly between the different ozone regimes, although a delay in current-year fine root shedding was found under the elevated ozone concentrations. The data indicate that increasing tropospheric ozone levels can alter the timing of fine root turnover in mature F. sylvatica but do not affect the turnover rate. - Doubling of ozone concentrations in mature European beech affected the seasonal timing of fine root turnover rather than the turnover rate.

  13. Nitrogen economics of root foraging: transitive closure of the nitrate-cytokinin relay and distinct systemic signaling for N supply vs. demand.

    Science.gov (United States)

    Ruffel, Sandrine; Krouk, Gabriel; Ristova, Daniela; Shasha, Dennis; Birnbaum, Kenneth D; Coruzzi, Gloria M

    2011-11-08

    As sessile organisms, root plasticity enables plants to forage for and acquire nutrients in a fluctuating underground environment. Here, we use genetic and genomic approaches in a "split-root" framework--in which physically isolated root systems of the same plant are challenged with different nitrogen (N) environments--to investigate how systemic signaling affects genome-wide reprogramming and root development. The integration of transcriptome and root phenotypes enables us to identify distinct mechanisms underlying "N economy" (i.e., N supply and demand) of plants as a system. Under nitrate-limited conditions, plant roots adopt an "active-foraging strategy", characterized by lateral root outgrowth and a shared pattern of transcriptome reprogramming, in response to either local or distal nitrate deprivation. By contrast, in nitrate-replete conditions, plant roots adopt a "dormant strategy", characterized by a repression of lateral root outgrowth and a shared pattern of transcriptome reprogramming, in response to either local or distal nitrate supply. Sentinel genes responding to systemic N signaling identified by genome-wide comparisons of heterogeneous vs. homogeneous split-root N treatments were used to probe systemic N responses in Arabidopsis mutants impaired in nitrate reduction and hormone synthesis and also in decapitated plants. This combined analysis identified genetically distinct systemic signaling underlying plant N economy: (i) N supply, corresponding to a long-distance systemic signaling triggered by nitrate sensing; and (ii) N demand, experimental support for the transitive closure of a previously inferred nitrate-cytokinin shoot-root relay system that reports the nitrate demand of the whole plant, promoting a compensatory root growth in nitrate-rich patches of heterogeneous soil.

  14. Root patterning

    NARCIS (Netherlands)

    Scheres, Ben; Laskowski, Marta

    2016-01-01

    The mechanisms that pattern lateral root primordial are essential for the elaboration of root system architecture, a trait of key importance for future crop breeding. But which are most important: periodic or local cues? In this issue of Journal of Experimental Botany (pages 1411-1420), Kircher

  15. Quality aspects of ex vivo root canal treatments done by undergraduate dental students using four different endodontic treatment systems.

    Science.gov (United States)

    Jungnickel, Luise; Kruse, Casper; Vaeth, Michael; Kirkevang, Lise-Lotte

    2018-04-01

    To evaluate factors associated with treatment quality of ex vivo root canal treatments performed by undergraduate dental students using different endodontic treatment systems. Four students performed root canal treatment on 80 extracted human teeth using four endodontic treatment systems in designated treatment order following a Latin square design. Lateral seal and length of root canal fillings was radiographically assessed; for lateral seal, a graded visual scale was used. Treatment time was measured separately for access preparation, biomechanical root canal preparation, obturation and for the total procedure. Mishaps were registered. An ANOVA mirroring the Latin square design was performed. Use of machine-driven nickel-titanium systems resulted in overall better quality scores for lateral seal than use of the manual stainless-steel system. Among systems with machine-driven files, scores did not significantly differ. Use of machine-driven instruments resulted in shorter treatment time than manual instrumentation. Machine-driven systems with few files achieved shorter treatment times. With increasing number of treatments, root canal-filling quality increased, treatment time decreased; a learning curve was plotted. No root canal shaping file separated. The use of endodontic treatment systems with machine-driven files led to higher quality lateral seal compared to the manual system. The three contemporary machine-driven systems delivered comparable results regarding quality of root canal fillings; they were safe to use and provided a more efficient workflow than the manual technique. Increasing experience had a positive impact on the quality of root canal fillings while treatment time decreased.

  16. Proteomics of Maize Root Development.

    Science.gov (United States)

    Hochholdinger, Frank; Marcon, Caroline; Baldauf, Jutta A; Yu, Peng; Frey, Felix P

    2018-01-01

    Maize forms a complex root system with structurally and functionally diverse root types that are formed at different developmental stages to extract water and mineral nutrients from soil. In recent years proteomics has been intensively applied to identify proteins involved in shaping the three-dimensional architecture and regulating the function of the maize root system. With the help of developmental mutants, proteomic changes during the initiation and emergence of shoot-borne, lateral and seminal roots have been examined. Furthermore, root hairs were surveyed to understand the proteomic changes during the elongation of these single cell type structures. In addition, primary roots have been used to study developmental changes of the proteome but also to investigate the proteomes of distinct tissues such as the meristematic zone, the elongation zone as well as stele and cortex of the differentiation zone. Moreover, subcellular fractions of the primary root including cell walls, plasma membranes and secreted mucilage have been analyzed. Finally, the superior vigor of hybrid seedling roots compared to their parental inbred lines was studied on the proteome level. In summary, these studies provide novel insights into the complex proteomic interactions of the elaborate maize root system during development.

  17. Proteomics of Maize Root Development

    Directory of Open Access Journals (Sweden)

    Frank Hochholdinger

    2018-03-01

    Full Text Available Maize forms a complex root system with structurally and functionally diverse root types that are formed at different developmental stages to extract water and mineral nutrients from soil. In recent years proteomics has been intensively applied to identify proteins involved in shaping the three-dimensional architecture and regulating the function of the maize root system. With the help of developmental mutants, proteomic changes during the initiation and emergence of shoot-borne, lateral and seminal roots have been examined. Furthermore, root hairs were surveyed to understand the proteomic changes during the elongation of these single cell type structures. In addition, primary roots have been used to study developmental changes of the proteome but also to investigate the proteomes of distinct tissues such as the meristematic zone, the elongation zone as well as stele and cortex of the differentiation zone. Moreover, subcellular fractions of the primary root including cell walls, plasma membranes and secreted mucilage have been analyzed. Finally, the superior vigor of hybrid seedling roots compared to their parental inbred lines was studied on the proteome level. In summary, these studies provide novel insights into the complex proteomic interactions of the elaborate maize root system during development.

  18. Virtual Plants Need Water Too: Functional-Structural Root System Models in the Context of Drought Tolerance Breeding.

    Science.gov (United States)

    Ndour, Adama; Vadez, Vincent; Pradal, Christophe; Lucas, Mikaël

    2017-01-01

    Developing a sustainable agricultural model is one of the great challenges of the coming years. The agricultural practices inherited from the Green Revolution of the 1960s show their limits today, and new paradigms need to be explored to counter rising issues such as the multiplication of climate-change related drought episodes. Two such new paradigms are the use of functional-structural plant models to complement and rationalize breeding approaches and a renewed focus on root systems as untapped sources of plant amelioration. Since the late 1980s, numerous functional and structural models of root systems were developed and used to investigate the properties of root systems in soil or lab-conditions. In this review, we focus on the conception and use of such root models in the broader context of research on root-driven drought tolerance, on the basis of root system architecture (RSA) phenotyping. Such models result from the integration of architectural, physiological and environmental data. Here, we consider the different phenotyping techniques allowing for root architectural and physiological study and their limits. We discuss how QTL and breeding studies support the manipulation of RSA as a way to improve drought resistance. We then go over the integration of the generated data within architectural models, how those architectural models can be coupled with functional hydraulic models, and how functional parameters can be measured to feed those models. We then consider the assessment and validation of those hydraulic models through confrontation of simulations to experimentations. Finally, we discuss the up and coming challenges facing root systems functional-structural modeling approaches in the context of breeding.

  19. Virtual Plants Need Water Too: Functional-Structural Root System Models in the Context of Drought Tolerance Breeding

    Directory of Open Access Journals (Sweden)

    Adama Ndour

    2017-09-01

    Full Text Available Developing a sustainable agricultural model is one of the great challenges of the coming years. The agricultural practices inherited from the Green Revolution of the 1960s show their limits today, and new paradigms need to be explored to counter rising issues such as the multiplication of climate-change related drought episodes. Two such new paradigms are the use of functional-structural plant models to complement and rationalize breeding approaches and a renewed focus on root systems as untapped sources of plant amelioration. Since the late 1980s, numerous functional and structural models of root systems were developed and used to investigate the properties of root systems in soil or lab-conditions. In this review, we focus on the conception and use of such root models in the broader context of research on root-driven drought tolerance, on the basis of root system architecture (RSA phenotyping. Such models result from the integration of architectural, physiological and environmental data. Here, we consider the different phenotyping techniques allowing for root architectural and physiological study and their limits. We discuss how QTL and breeding studies support the manipulation of RSA as a way to improve drought resistance. We then go over the integration of the generated data within architectural models, how those architectural models can be coupled with functional hydraulic models, and how functional parameters can be measured to feed those models. We then consider the assessment and validation of those hydraulic models through confrontation of simulations to experimentations. Finally, we discuss the up and coming challenges facing root systems functional-structural modeling approaches in the context of breeding.

  20. Diagnosis and root canal treatment in a mandibular premolar with three canals.

    Science.gov (United States)

    Soares, Lanuce Rosa; Arruda, Marcos; de Arruda, Marcos Pôrto; Rangel, Andréa Leão; Takano, Edson; de Carvalho Júnior, Jacy Ribeiro; Saquy, Paulo Cesar

    2009-01-01

    This paper presents a case report of a left mandibular second premolar with three canals and three different apical foramina. A 39-year-old male patient presented to our clinic with pain in the mandibular left second premolar. Initially, pain was caused by cold stimulus and later was spontaneously. The intraoral clinical examination revealed a fractured amalgam restoration with occlusal caries. Percussion and cold (Endo-Frost) tests were positive. The radiographic examination showed the presence of two roots. The probable diagnosis was an acute pulpitis. After access cavity, it was observed remaining roof of the pulp chamber and mild bleeding in the tooth lingual area, indicating the possible presence of a third canal. The endodontic treatment was completed in a single session using Root ZX apex locator and K3 NiTi rotary system with surgical diameter corresponding to a .02/45 file in the three canals and irrigation with 1% sodium hypochlorite. The canals were obtured with gutta-percha cones and Sealer 26 using the lateral condensation technique. After 1 year of follow-up, the tooth was asymptomatic and periapical repair was observed radiographically. Internal alterations should be considered during the endodontic treatment of mandibular second premolars. The correct diagnosis of these alterations by the analysis of preoperative radiographs can help the location of two or more canals, thereby avoiding root therapy failure.

  1. A New Anatomically Based Nomenclature for the Roots and Root Canals—Part 1: Maxillary Molars

    Directory of Open Access Journals (Sweden)

    Jojo Kottoor

    2012-01-01

    Full Text Available Numerous terminologies have been employed in the dental literature to describe the roots and root canal systems of maxillary molars. This multiplicity in naming of roots and canals makes the reader susceptible to misinterpretation and confusion. No consensus thus far has been arrived at for defining the names of roots and root canals in maxillary molars, including their various morphological aberrations. The anatomical relation of roots and their root canals were identified and were subsequently named based on definite sets of criteria. A new method for identification and naming of roots and root canal anatomy in maxillary molars, based on their root and canal relationship, was formulated and is presented in this paper. The nomenclature makes certain essential modifications to the traditional approach to accommodate naming of the various aberrations presented in the maxillary molars. A simple, yet extensive, nomenclature system has been proposed that appropriately names the internal and external morphology of maxillary molars.

  2. A new anatomically based nomenclature for the roots and root canals-part 1: maxillary molars.

    Science.gov (United States)

    Kottoor, Jojo; Albuquerque, Denzil Valerian; Velmurugan, Natanasabapathy

    2012-01-01

    Numerous terminologies have been employed in the dental literature to describe the roots and root canal systems of maxillary molars. This multiplicity in naming of roots and canals makes the reader susceptible to misinterpretation and confusion. No consensus thus far has been arrived at for defining the names of roots and root canals in maxillary molars, including their various morphological aberrations. The anatomical relation of roots and their root canals were identified and were subsequently named based on definite sets of criteria. A new method for identification and naming of roots and root canal anatomy in maxillary molars, based on their root and canal relationship, was formulated and is presented in this paper. The nomenclature makes certain essential modifications to the traditional approach to accommodate naming of the various aberrations presented in the maxillary molars. A simple, yet extensive, nomenclature system has been proposed that appropriately names the internal and external morphology of maxillary molars.

  3. RUNTIME DICTIONARIES FOR ROOT

    CERN Document Server

    Wind, David Kofoed

    2013-01-01

    ROOT is the LHC physicists' common tool for data analysis; almost all data is stored using ROOT's I/O system. This system benefits from a custom description of types (a so-called dictionary) that is optimised for the I/O. Until now, the dictionary cannot be provided at run-time; it needs to be prepared in a separate prerequisite step. This project will move the generation of the dictionary to run-time, making use of ROOT 6's new just-in-time compiler. It allows a more dynamic and natural access to ROOT's I/O features especially for user code.

  4. Dynamics of organic matters in the root-rhizoplane-soil system of maize [Zea mays], 1: A simple and rapid method for measuring root respiration

    Energy Technology Data Exchange (ETDEWEB)

    Okada, K. [Tokyo Univ., Tokyo (Japan); Kumura, A.

    1990-03-15

    In the analysis of dynamics of organic matter in the root-rhizoplane-soil system, it is essential to estimate various kinds of carbon flows in the system separately. Since a simple and rapid method for measuring root respiration was needed for this purpose, the authors developed the following method. A plastic syringe is used as the chamber. Sample roots are put into a syringe, in which the air is replaced with air of known CO{sub 2} concentration and the syringe is kept at a constant temperature for a certain time. A volume of the air in the syringe is injected into the flow of N{sub 2} gas in the tube which is connected to an infrared gas analyzer. The CO{sub 2} concentration in the syringe is directly related to the reading of the analyzer. From the difference of the CO{sub 2} concentration in the syringe before and after the incubation, the respiration rate of the roots is calculated. The details of the procedure were determined by the results of experiments regarding the effects of factors concerned. (author)

  5. Technological advances in endodontics: treatment of a mandibular molar with internal root resorption using a reciprocating single-file system.

    Science.gov (United States)

    de Souza, Samir Noronha; Marques, André Augusto Franco; Sponchiado-Júnior, EmÍlio Carlos; Roberti Garcia, Lucas da Fonseca; da Frota, Matheus Franco; de Carvalho, Fredson Márcio Acris

    2017-01-01

    The field of endodontics has become increasingly successful due to technological advances that allow clinicians to solve clinical cases that would have been problematic a few years ago. Despite such advances, endodontic treatment of teeth with internal root resorption remains challenging. This article presents a clinical case in which a reciprocating single-file system was used for endodontic treatment of a mandibular molar with internal root resorption. Radiographic examination revealed the presence of internal root resorption in the distobuccal root canal of the mandibular right first molar. A reciprocating single-file system was used for root canal instrumentation and final preparation, and filling was obtained through a thermal compaction technique. No painful symptoms or periapical lesions were observed in 12 months of follow-up. The results indicate that a reciprocating single-file system is an adequate alternative for root canal instrumentation, particularly in teeth with internal root resorption.

  6. Primary root protophloem differentiation requires balanced phosphatidylinositol-4,5-biphosphate levels and systemically affects root branching.

    NARCIS (Netherlands)

    Rodriguez-Villalon, A.; Gujas, B.; van Wijk, R.; Munnik, T.; Hardtke, C.S.

    2015-01-01

    Protophloem is a specialized vascular tissue in growing plant organs, such as root meristems. In Arabidopsis mutants with impaired primary root protophloem differentiation, brevis radix (brx) and octopus (ops), meristematic activity and consequently overall root growth are strongly reduced. Second

  7. PLASMA-MEMBRANE LIPID ALTERATIONS INDUCED BY NACL IN WINTER-WHEAT ROOTS

    NARCIS (Netherlands)

    MANSOUR, MMF; VANHASSELT, PR; KUIPER, PJC

    A highly enriched plasma membrane fraction was isolated by two phase partitioning from wheat roots (Triticum aestivum L. cv. Vivant) grown with and without 100 mM NaCl. The lipids of the plasma membrane fraction were extracted and characterized. Phosphatidylcholine and phosphatidylethanolamine were

  8. Distinct modes of adventitious rooting in Arabidopsis thaliana.

    Science.gov (United States)

    Correa, L da Rocha; Troleis, J; Mastroberti, A A; Mariath, J E A; Fett-Neto, A G

    2012-01-01

    The literature describes different rooting protocols for Arabidopsis thaliana as models to study adventitious rooting, and results are generally perceived as comparable. However, there is a lack of investigations focusing on the distinct features, advantages and limitations of each method in the study of adventitious rooting with both wild-type (WT) ecotypes and their respective mutants. This investigation was undertaken to evaluate the adventitious rooting process in three different experimental systems, all using A. thaliana, analysing the same rooting parameters after transient exposure to auxin (indole-3-acetic acid) and control conditions: excised leaves, de-rooted plants and etiolated seedlings. The founding tissues and sites of origin of roots differed depending on the system used, whereas all rooting patterns were of the direct type (i.e., without callus formation). None of the systems had an absolute requirement for exogenous auxin, although rooting was enhanced by this phytohormone, with the exception of de-rooted plants, which had adventitious rooting strongly inhibited by exogenous auxin. Root elongation was much favoured in isolated leaves. Auxin-overproducing mutants could not be used in the detached leaf system due to precocious senescence; in the de-rooted plant system, these mutants had a WT-like rooting response, whereas the expression of the 'rooty' phenotype was only evident in the etiolated seedling system. Adventitious rooting of etiolated WT seedlings in the presence of exogenous auxin was inhibited by exogenous flavonoids, which act as auxin transport inhibitors; surprisingly, the flavonoid-deficient mutant chs had a lower rooting response compared to WT. Although Arabidopsis is an excellent model system to study adventitious rooting, physiological and developmental responses differed significantly, underlining the importance of avoiding data generalisation on rooting responses derived from different experimental systems with this species.

  9. A New Anatomically Based Nomenclature for the Roots and Root Canals—Part 1: Maxillary Molars

    OpenAIRE

    Kottoor, Jojo; Albuquerque, Denzil Valerian; Velmurugan, Natanasabapathy

    2012-01-01

    Numerous terminologies have been employed in the dental literature to describe the roots and root canal systems of maxillary molars. This multiplicity in naming of roots and canals makes the reader susceptible to misinterpretation and confusion. No consensus thus far has been arrived at for defining the names of roots and root canals in maxillary molars, including their various morphological aberrations. The anatomical relation of roots and their root canals were identified and were subsequen...

  10. Osmolarity and root canal antiseptics.

    Science.gov (United States)

    Rossi-Fedele, G; Guastalli, A R

    2014-04-01

    Antiseptics used in endodontics for disinfection purposes include root canal dressings and irrigants. Osmotic shock is known to cause the alteration of microbial cell viability and might have a role in the mechanism of action of root canal antiseptics. The aim of this review was to determine the role of osmolarity on the performance of antiseptics in root canal treatment. A literature search using the Medline electronic database was conducted up to 30 May 2013 using the following search terms and combinations: 'osmolarity AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; osmolality AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; osmotic AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; osmosis AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; sodium chloride AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm'. Publications were included if the effects of osmolarity on the clinical performance of antiseptics in root canal treatment were stated, if preparations with different osmolarities values were compared and if they were published in English. A hand search of articles published online, 'in press' and 'early view', and in the reference list of the included papers was carried out following the same criteria. A total of 3274 publications were identified using the database, and three were included in the review. The evidence available in endodontics suggests a possible role for hyperosmotic root canal medicaments as disinfectants, and that there is no influence of osmolarity on the tissue dissolution capacity of sodium hypochlorite. There are insufficient data to obtain a sound conclusion regarding the role of hypo-osmosis in root canal disinfection, or osmosis in any further desirable

  11. Multi-walled carbon nanotubes can enhance root elongation of wheat (Triticum aestivum) plants

    International Nuclear Information System (INIS)

    Wang Xiuping; Han Heyou; Liu Xueqin; Gu Xiaoxu; Chen Kun; Lu Donglian

    2012-01-01

    The potential effects of oxidized multi-walled carbon nanotubes (o-MWCNTs) with a length ranging from 50 to 630 nm on the development and physiology of wheat plants were evaluated by examining their effects on seed germination, root elongation, stem length, and vegetative biomass at a concentration ranging from 10 to 160 μg/mL in the plant. Results indicated that after 7 days of exposure to the o-MWCNTs medium, faster root growth and higher vegetative biomass were observed, but seed germination and stem length did not show any difference as compared with controls. Moreover, a physiological study was conducted at cellular level using a traditional physiological approach to evidence the possible alterations in morphology, the cell length of root zone, and the dehydrogenase activity of seedlings. Transmission electron microscopy images revealed that o-MWCNTs could penetrate the cell wall and enter the cytoplasm after being taken up by roots. The cell length of root zone for the seedlings germinated and grown in the o-MWCNTs (80 μg/mL) medium increased by 1.4-fold and a significant concentration-dependent increase in the dehydrogenase activity for the o-MWCNT-treated wheat seedlings was detected. These findings suggest that o-MWCNTs can significantly promote cell elongation in the root system and increase the dehydrogenase activity, resulting in faster root growth and higher biomass production.

  12. Multi-walled carbon nanotubes can enhance root elongation of wheat (Triticum aestivum) plants

    Energy Technology Data Exchange (ETDEWEB)

    Wang Xiuping; Han Heyou, E-mail: hyhan@mail.hzau.edu.cn; Liu Xueqin; Gu Xiaoxu; Chen Kun; Lu Donglian [Huazhong Agricultural University, College of Science, State Key Laboratory of Agricultural Microbiology, Institute of Chemical Biology (China)

    2012-06-15

    The potential effects of oxidized multi-walled carbon nanotubes (o-MWCNTs) with a length ranging from 50 to 630 nm on the development and physiology of wheat plants were evaluated by examining their effects on seed germination, root elongation, stem length, and vegetative biomass at a concentration ranging from 10 to 160 {mu}g/mL in the plant. Results indicated that after 7 days of exposure to the o-MWCNTs medium, faster root growth and higher vegetative biomass were observed, but seed germination and stem length did not show any difference as compared with controls. Moreover, a physiological study was conducted at cellular level using a traditional physiological approach to evidence the possible alterations in morphology, the cell length of root zone, and the dehydrogenase activity of seedlings. Transmission electron microscopy images revealed that o-MWCNTs could penetrate the cell wall and enter the cytoplasm after being taken up by roots. The cell length of root zone for the seedlings germinated and grown in the o-MWCNTs (80 {mu}g/mL) medium increased by 1.4-fold and a significant concentration-dependent increase in the dehydrogenase activity for the o-MWCNT-treated wheat seedlings was detected. These findings suggest that o-MWCNTs can significantly promote cell elongation in the root system and increase the dehydrogenase activity, resulting in faster root growth and higher biomass production.

  13. Root proliferation in decaying roots and old root channels: A nutrient conservation mechanism in oligotrophic mangrove forests?

    Science.gov (United States)

    McKee, K.L.

    2001-01-01

    1. In oligotrophic habitats, proliferation of roots in nutrient-rich microsites may contribute to overall nutrient conservation by plants. Peat-based soils on mangrove islands in Belize are characterized by the presence of decaying roots and numerous old root channels (0.1-3.5 cm diameter) that become filled with living and highly branched roots of Rhizophora mangle and Avicennia germinans. The objectives of this study were to quantify the proliferation of roots in these microsites and to determine what causes this response. 2. Channels formed by the refractory remains of mangrove roots accounted for only 1-2% of total soil volume, but the proportion of roots found within channels varied from 9 to 24% of total live mass. Successive generations of roots growing inside increasingly smaller root channels were also found. 3. When artificial channels constructed of PVC pipe were buried in the peat for 2 years, those filled with nutrient-rich organic matter had six times more roots than empty or sand-filled channels, indicating a response to greater nutrient availability rather than to greater space or less impedance to root growth. 4. Root proliferation inside decaying roots may improve recovery of nutrients released from decomposing tissues before they can be leached or immobilized in this intertidal environment. Greatest root proliferation in channels occurred in interior forest zones characterized by greater soil waterlogging, which suggests that this may be a strategy for nutrient capture that minimizes oxygen losses from the whole root system. 5. Improved efficiency of nutrient acquisition at the individual plant level has implications for nutrient economy at the ecosystem level and may explain, in part, how mangroves persist and grow in nutrient-poor environments.

  14. Concept for Sustained Plant Production on ISS Using VEGGIE Capillary Mat Rooting System

    Science.gov (United States)

    Stutte, Gary W.; Newsham, Gerard; Morrow, Robert M.; Wheeler, Raymond M.

    2011-01-01

    Plant growth in microgravity presents unique challenges associated with maintaining appropriate conditions for seed germination, seedling establishment, maturation and harvest. They include maintaining appropriate soil moisture content, nutrient balance, atmospheric mixing and containment. Sustained production imposes additional challenges of harvesting, replanting, and safety. The VEGGIE is a deployable (collapsible) plant growth chamber developed as part of a NASA SBIR Phase II by Orbitec, Madison, WI. The intent of VEGGIE is to provide a low-resource system to produce fresh vegetables for the crew on long duration missions. The VEGGIE uses and LED array for lighting, an expandable bellows for containment, and a capillary matting system for nutrient and water delivery. The project evaluated a number of approaches to achieve sustained production, and repeated plantings, using the capillary rooting system. A number of different root media, seed containment, and nutrient delivery systems were evaluated and effects on seed germination and growth were evaluated. A number of issues limiting sustained production, such as accumulation of nutrients, uniform water, elevated vapor pressure deficit, and media containment were identified. A concept using pre-planted rooting packs shown to effectively address a number of those issues and is a promising approach for future development as a planting system for microgravity conditions.

  15. The McMillan and Newton polygons of a feedback system and the construction of root loci

    Science.gov (United States)

    Byrnes, C. I.; Stevens, P. K.

    1982-01-01

    The local behaviour of root loci around zeros and poles is investigated. This is done by relating the Newton diagrams which arise in the local analysis to the McMillan structure of the open-loop system, by means of what we shall call the McMillan polygon. This geometric construct serves to clarify the precise relationship between the McMillan structure, the principal structure, and the branching patterns of the root loci. In addition, several rules are obtained which are useful in the construction of the root loci of multivariable control systems.

  16. Studies using 32P to determine the distribution and activity patterns of the oil palm root system in Nigeria

    International Nuclear Information System (INIS)

    Omoti, U.

    1982-01-01

    Results of studies of the root distribution and root activity which have been conducted by the Nigerian Institute for Oil Palm Research over the last twenty-three years are presented. Previous laborious studies involving washing the soil from the entire root system have shown that the oil palm root system is typically monocotyledonous with superficial and deeply penetrating primaries, ascending and descending secondaries with numerous tertiaries and quaternaries in the surface layers forming the main feeding roots. Radioisotope studies showed that the greatest concentration and activity of the nutrient absorbing roots occurred within the top 30 cm of soil. There were zones of root concentration and root activity close to the palm. High root activity was also obtained up to 4 m from the palm. During the dry season, the oil palm roots die back thus leading to a reduced zone of root activity. The implications of the findings for fertilizer placement for maximum efficiency of utilization by the whole plantation and the need for further experimentation are discussed. (author)

  17. New simple algebraic root locus method for design of feedback control systems

    Directory of Open Access Journals (Sweden)

    Cingara Aleksandar M.

    2008-01-01

    Full Text Available New concept of algebraic characteristic equation decomposition method is presented to simplify the design of closed-loop systems for practical applications. The method consists of two decompositions. The first one, decomposition of the characteristic equation into two lower order equations, was performed in order to simplify the analysis and design of closed loop systems. The second is the decomposition of Laplace variable, s, into two variables, damping coefficient, ζ, and natural frequency, ω n. Those two decompositions reduce the design of any order feedback systems to setting of two complex dominant poles in the desired position. In the paper, we derived explicit equations for six cases: first, second and third order system with P and PI. We got the analytical solutions for the case of fourth and fifth order characteristic equations with the P and PI controller; one may obtain a complete analytical solution of controller gain as a function of the desired damping coefficient. The complete derivation is given for the third order equation with P and PI controller. We can extend the number of specified poles to the highest order of the characteristic equation working in a similar way, so we can specify the position of each pole. The concept is similar to the root locus but root locus is implicit, which makes it more complicated and this is simpler explicit root locus. Standard procedures, root locus and Bode diagrams or Nichol Charts, are neither algebraic nor explicit. We basically change controller parameters and observe the change of some function until we get the desired specifications. The derived method has three important advantage over the standard procedures. It is general, algebraic and explicit. Those are the best poles design results possible; it is not possible to get better controller design results.

  18. 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.

  19. Two negative regulatory systems of root nodule symbiosis - how are symbiotic benefits and costs balanced?

    Science.gov (United States)

    Nishida, Hanna; Suzaki, Takuya

    2018-05-30

    Root nodule symbiosis is one of the best-characterized mutualistic relationships between plants-microbes symbiosis, where mainly leguminous species can obtain nitrogen sources fixed by nitrogen-fixing rhizobia through the formation of symbiotic organs root nodules. In order to drive this symbiotic process, plants need to provide carbon sources that should be used for their growth. Therefore, a balance between the benefits of obtaining nitrogen sources and the costs of losing carbon sources needs to be maintained during root nodule symbiosis. Plants have developed at least two negative regulatory systems of root nodule symbiosis. One strategy involves the regulation of nodule number in response to rhizobial infection. For this regulation, a systemic long-range signaling between roots and shoots called autoregulation of nodulation has a pivotal role. Another strategy involves the regulation of root nodule symbiosis in response to nitrate, the most abundant form of nitrogen nutrients in the soil. Recent studies indicate that a long-distance signaling is shared between the two strategies, where NIN and NRSYM1, two paralogous RWP-RK transcription factors, can activate the production of nodulation-related CLE peptides in response to different inputs. Here, we give an overview of such progress in our understanding of molecular mechanisms relevant to the control of the symbiotic balance, including their biological significance.

  20. Differential effects of fine root morphology on water dynamics in the root-soil interface

    Science.gov (United States)

    DeCarlo, K. F.; Bilheux, H.; Warren, J.

    2017-12-01

    Soil water uptake form plants, particularly in the rhizosphere, is a poorly understood question in the plant and soil sciences. Our study analyzed the role of belowground plant morphology on soil structural and water dynamics of 5 different plant species (juniper, grape, maize, poplar, maple), grown in sandy soils. Of these, the poplar system was extended to capture drying dynamics. Neutron radiography was used to characterize in-situ dynamics of the soil-water-plant system. A joint map of root morphology and soil moisture was created for the plant systems using digital image processing, where soil pixels were connected to associated root structures via minimum distance transforms. Results show interspecies emergent behavior - a sigmoidal relationship was observed between root diameter and bulk/rhizosphere soil water content difference. Extending this as a proxy for extent of rhizosphere development with root age, we observed a logistic growth pattern for the rhizosphere: minimal development in the early stages is superceded by rapid onset of rhizosphere formation, which then stabilizes/decays with the likely root suberization. Dynamics analysis of water content differences between the root/rhizosphere, and rhizosphere/bulk soil interface highlight the persistently higher water content in the root at all water content and root size ranges. At the rhizosphere/bulk soil interface, we observe a shift in soil water dynamics by root size: in super fine roots, we observe that water content is primarily lower in the rhizosphere under wetter conditions, which then gradually increases to a relatively higher water content under drier conditions. This shifts to a persistently higher rhizosphere water content relative to bulk soil in both wet/dry conditions with increased root size, suggesting that, by size, the finest root structures may contribute the most to total soil water uptake in plants.

  1. Fourier transforms related to a root system of rank 1.

    NARCIS (Netherlands)

    Groenevelt, W.G.M.

    2007-01-01

    Abstract : We introduce an algebra $\\mathcal H$ consisting of difference-reflection operators and multiplication operators that can be considered as a q = 1 analogue of Sahi's double affine Hecke algebra related to the affine root system of type $(C^\\vee_1, C_1)$ . We study eigenfunctions of a

  2. Evaluation of apically extruded debris during root canal retreatment with several NiTi systems.

    Science.gov (United States)

    Dincer, A N; Er, O; Canakci, B C

    2015-12-01

    To compare the amount of debris extruded apically during root canal retreatment using ProTaper, Mtwo and Reciproc instruments with hand H-files. In total, 60 freshly extracted human mandibular incisor teeth were used. All root canals were prepared with a Reciproc R25 file than filled with Gutta-percha and AH Plus sealer using cold lateral condensation before being assigned randomly to four groups (n = 15 each). In group 1, root fillings were removed with the Protaper Universal retreatment system; ProTaper Universal F3 and F4 instruments were used for the final preparation. In group 2, root fillings were removed with the Mtwo retreatment system; Mtwo size 30, .06 taper, size 35, .06 taper and size 40, .06 taper files were used for the final preparation. In group 3, root fillings were removed with Reciproc R25 instruments; Reciproc R40 instruments were used for the final preparation. In group 4, the root fillings were removed with Gates Glidden burs and sizes 35, 30 and 25 H-files; for final preparation, a size 40 H-file was used. Glass vials were used for debris collection. The vials were weighed before and after Gutta-percha removal. Additionally, the times required for the retreatment procedures were recorded. Data were analysed statistically using one-way analysis of variance. The Reciproc system produced significantly smaller amounts of apical extruded debris than the other groups (P ProTaper groups. The ProTaper and Reciproc groups required significantly less time than the Mtwo and H-file groups (P hand filing. Use of the ProTaper and Reciproc instruments required less time for retreatment procedures than use of the Mtwo or H-file. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  3. In-depth morphological study of mesiobuccal root canal systems in maxillary first molars: review

    Directory of Open Access Journals (Sweden)

    Seok-Woo Chang

    2013-02-01

    Full Text Available A common failure in endodontic treatment of the permanent maxillary first molars is likely to be caused by an inability to locate, clean, and obturate the second mesiobuccal (MB canals. Because of the importance of knowledge on these additional canals, there have been numerous studies which investigated the maxillary first molar MB root canal morphology using in vivo and laboratory methods. In this article, the protocols, advantages and disadvantages of various methodologies for in-depth study of maxillary first molar MB root canal morphology were discussed. Furthermore, newly identified configuration types for the establishment of new classification system were suggested based on two image reformatting techniques of micro-computed tomography, which can be useful as a further 'Gold Standard' method for in-depth morphological study of complex root canal systems.

  4. Temperature increases on the external root surface during endodontic treatment using single file systems.

    Science.gov (United States)

    Özkocak, I; Taşkan, M M; Gökt Rk, H; Aytac, F; Karaarslan, E Şirin

    2015-01-01

    The aim of this study is to evaluate increases in temperature on the external root surface during endodontic treatment with different rotary systems. Fifty human mandibular incisors with a single root canal were selected. All root canals were instrumented using a size 20 Hedstrom file, and the canals were irrigated with 5% sodium hypochlorite solution. The samples were randomly divided into the following three groups of 15 teeth: Group 1: The OneShape Endodontic File no.: 25; Group 2: The Reciproc Endodontic File no.: 25; Group 3: The WaveOne Endodontic File no.: 25. During the preparation, the temperature changes were measured in the middle third of the roots using a noncontact infrared thermometer. The temperature data were transferred from the thermometer to the computer and were observed graphically. Statistical analysis was performed using the Kruskal-Wallis analysis of variance at a significance level of 0.05. The increases in temperature caused by the OneShape file system were lower than those of the other files (P file showed the highest temperature increases. However, there were no significant differences between the Reciproc and WaveOne files. The single file rotary systems used in this study may be recommended for clinical use.

  5. Wheat shovelomics I: A field phenotyping approach for characterising the structure and function of root systems in tillering species

    OpenAIRE

    Bennett, Malcolm; York, Larry; Foulkes, M; Slack, Shaunagh

    2018-01-01

    Wheat represents a major crop, yet the current rate of yield improvement is insufficient to meet its projected global food demand. Breeding root systems more efficient for water and nitrogen capture represents a promising avenue for accelerating yield gains. Root crown phenotyping, or shovelomics, relies on excavation of the upper portions of root systems in the field and measuring root properties such as numbers, angles, densities and lengths. We report a new shovelomics method that images t...

  6. Variations in the Root Form and Root Canal Morphology of Permanent Mandibular First Molars in a Sri Lankan Population

    Directory of Open Access Journals (Sweden)

    Roshan Peiris

    2015-01-01

    Full Text Available The present study was conducted to determine the number of roots and morphology of the root canal system of permanent mandibular first molars (M1 in a Sri Lankan population. Sample of 529 M1 teeth was used. The number of roots was examined and the lengths of the mesial and distal roots were measured to the nearest 0.01 mm. Vacuum injection protocol was used to inject China ink into the root canal system, making it transparent. Root canal morphology was recorded using Vertucci’s classification. Presence of furcation canals, position of lateral canals, intercanal communications, level of bifurcation, and convergence of the root canal system were recorded. M1 showed three roots in 4.1% of the sample. Commonest root canal morphology of the mesial root was type IV and the distal root was type I. The level of bifurcation of the root canals was commonly observed in the cervical one-third of the root while convergence was observed in the apical one-third in both roots. Prevalence of three rooted mandibular first molars is less than 5%. Mesial root showed the most variable canal morphology. Prevalence of furcation canals was 1.5% while that of middle mesial canals was 0.2%.

  7. Root cause analysis of pump valve failures of three membrane pump systems

    NARCIS (Netherlands)

    Buijs, L.J.; Eijk, A.; Hooft, L. van

    2014-01-01

    This paper will present the root cause analysis and the solution of fatigue failures of the pump valves of three membrane pump systems installed on a chemical plant of Momentive in Pernis, the Netherlands. The membrane pumps were installed approximately 30 years ago. Each system has encountered

  8. Altered growth and fine root chemistry of Betula papyrifera and Acer saccharum under elevated CO2

    International Nuclear Information System (INIS)

    Parsons, W. F. J.; Kopper, B. J.; Lindroth, R. L.

    2003-01-01

    The effects of carbon dioxide enrichment on fine root chemical composition of two tree species common to northern hardwood forests was investigated. Results showed no change in the root/shoot ratios and fine root percentages in either birch or maple samples as a result of enriched carbon dioxide. Tissue nitrogen concentrations decreased in the fine roots, and consequently, carbon/nitrogen ratios increased with elevated carbon dioxide. In birch only, condensed tannins increased with carbon dioxide enrichment; in maple, neither complex tannins nor hydrosable tannins appear to have been influenced by elevated carbon dioxide. It is suspected that the responses of the tree saplings to elevated carbon dioxide may be related to their successional status. 37 refs., 2 tabs

  9. The Accuracy of the Digital imaging system and the frequency dependent type apex locator in root canal length measurement

    International Nuclear Information System (INIS)

    Lee, Byoung Rib; Park, Chang Seo

    1998-01-01

    In order to achieve a successful endodontic treatment, root canals must be obturated three-dimensionally without causing any damage to apical tissues. Accurate length determination of the root canal is critical in this case. For this reason, I've used the conventional periapical radiography, Digora (digital imaging system) and Root ZX (the frequency dependent type apex locator) to measure the length of the canal and compare it with the true length obtained by cutting the tooth in half and measuring the length between the occlusal surface and the apical foramen. From the information obtained by these measurements, I was able to evaluate the accuracy and clinical usefulness of each systems, whether the thickness of files used in endodontic therapy has any effect on the measuring systems was also evaluated in an effort to simplify the treatment planning phase of endodontic treatment. 29 canals of 29 sound premolars were measured with no 15, no 20, no 25 files by 3 different dentists each using the periapical radiography, Digora and Root ZX. The measurements were then compared with the true length. The results were as follows ; 1. In comparing mean discrepancies between measurements obtained by using periapical radiography (mean error : -0.449 ± 0.444 mm), Digora (mean error : -0.417 ± 0.415 mm) and Root ZX (mean error : 0.123 ± 0.458 mm) with true length, periapical radiography and Digora system had statistically significant differences (p 0.05). 2. By subtracting values obtained by using periapical radiography, Digora and Root ZX from the true length and making a distribution table of their absolute values, the following analysis was possible. In the case of periapical film, 140 out of 261 (53.6%) were clinically acceptable satisfying the margin of error of less than 0.5 mm, 151 out of 261 (53,6%) were acceptable in the Digora system while Root ZX had 197 out of 261 (75.5%) within the limits of 0.5 mm margin of error. 3. In determining whether the thickness of

  10. Lateral root organogenesis - from cell to organ.

    Science.gov (United States)

    Benková, Eva; Bielach, Agnieszka

    2010-12-01

    Unlike locomotive organisms capable of actively approaching essential resources, sessile plants must efficiently exploit their habitat for water and nutrients. This involves root-mediated underground interactions allowing plants to adapt to soils of diverse qualities. The root system of plants is a dynamic structure that modulates primary root growth and root branching by continuous integration of environmental inputs, such as nutrition availability, soil aeration, humidity, or salinity. Root branching is an extremely flexible means to rapidly adjust the overall surface of the root system and plants have evolved efficient control mechanisms, including, firstly initiation, when and where to start lateral root formation; secondly lateral root primordia organogenesis, during which the development of primordia can be arrested for a certain time; and thirdly lateral root emergence. Our review will focus on the most recent advances in understanding the molecular mechanisms involved in the regulation of lateral root initiation and organogenesis with the main focus on root system of the model plant Arabidopsis thaliana. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. 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...

  12. 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.

  13. Comparison of five cone beam computed tomography systems for the detection of vertical root fractures

    NARCIS (Netherlands)

    Hassan, B.; Metska, M.E.; Ozok, A.R.; van der Stelt, P.; Wesselink, P.R.

    2010-01-01

    Introduction This study compared the accuracy of cone beam computed tomography (CBCT) scans made by five different systems in detecting vertical root fractures (VRFs). It also assessed the influence of the presence of root canal filling (RCF), CBCT slice orientation selection, and the type of tooth

  14. Aqueous alteration of Japanese simulated waste glass P0798: Effects of alteration-phase formation on alteration rate and cesium retention

    International Nuclear Information System (INIS)

    Inagaki, Y.; Shinkai, A.; Idemistu, K.; Arima, T.; Yoshikawa, H.; Yui, M.

    2006-01-01

    Aqueous alteration tests were performed with a Japanese simulated waste glass P0798 in alkaline solutions as a function of pH or species/concentration of alkaline metals in the solution in order to evaluate the alteration conditions determining whether smectite (2:1 clay mineral) or analcime (zeolite) forms as the major alteration-phase. XRD analysis of the alteration-phases showed that smectite forms at any pH between 9.5 and 12, and analcime forms at pH above 11, though the formation also depends on species and concentrations of alkaline metals in the solution. These results cannot agree with the thermodynamically predicted phase stability, e.g., smectite is more stable than the thermodynamic prediction shows. On the basis of the results of alteration conditions, the alteration tests were performed under smectite forming conditions, where only smectite forms or no crystalline phases form, in order to evaluate the alteration rate and the mechanism of cesium release/retention. The results showed that the glass alteration proceeds slowly in proportion to square root of time under smectite forming conditions, which indicates that the alteration rate can be controlled by a diffusion process. It was suggested that the alteration rate under smectite forming conditions is independent of the pH, alkaline metal species/concentration in the solution and whether smectite actually forms or not. The results also indicated that most of cesium dissolved from the glass can be retained in the alteration-phases by reversible sorption onto smectite or irreversible incorporation into analcime, pollucite or solid solutions of them

  15. 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

  16. A comparative evaluation of the increase in root canal surface area and canal transportation in curved root canals by three rotary systems: A cone-beam computed tomographic study

    Science.gov (United States)

    Prasanthi, Nalam NVD; Rambabu, Tanikonda; Sajjan, Girija S; Varma, K Madhu; Satish, R Kalyan; Padmaja, M

    2016-01-01

    Aim: The aim of this study was to measure the increase in root canal surface area and canal transportation after biomechanical preparation at 1, 3, and 5 mm short of the apex with three different rotary systems in both continuous rotary and reciprocating rotary motions. Materials and Methods: Sixty freshly extracted human mandibular molars with mesial root canal curvatures between 20° and 30° were included in the study. Teeth were randomly distributed into three groups (n = 20). Biomechanical preparations were done in all the mesial canals. In Group 1, instrumentation was done with ProTaper universal rotary files, Group 2, with K3XF rotary files, and Group 3, with LSX rotary files. Each group was further subdivided into subgroups A and B (n = 10) where instrumentation was done by continuous rotary and reciprocating rotary techniques, respectively. Increase in root canal surface area and canal transportation was measured using the preoperative and postoperative cone-beam computed tomography scans. Statistical Analysis: The data were analyzed by one-way ANOVA followed by Tukey pairwise multiple comparison tests. Results: Increase in root canal surface area was significantly more (P 0.05) in increase of root canal surface area and canal transportation between continuous rotary and reciprocating rotary techniques for ProTaper Universal, K3XF and LSX groups. Conclusion: LSX rotary system showed minimal increase of root canal surface area and minimal canal transportation when compared to ProTaper and K3XF rotary systems. PMID:27656062

  17. The incidence of root microcracks caused by 3 different single-file systems versus the ProTaper system.

    Science.gov (United States)

    Liu, Rui; Hou, Ben Xiang; Wesselink, Paul R; Wu, Min-Kai; Shemesh, Hagay

    2013-08-01

    The aim of this study was to compare the incidence of root cracks observed at the apical root surface and/or in the canal wall after canal instrumentation with 3 single-file systems and the ProTaper system (Dentsply Maillefer, Ballaigues, Switzerland). One hundred mandibular incisors were selected. Twenty control teeth were coronally flared with Gates-Glidden drills (Dentsply Maillefer). No further preparation was made. The other 80 teeth were mounted in resin blocks with simulated periodontal ligaments, and the apex was exposed. They were divided into 4 experimental groups (n = 20); the root canals were first coronally flared with Gates-Glidden drills and then instrumented to the full working length with the ProTaper, OneShape (Micro-Mega, Besancon, France), Reciproc (VDW, Munich, Germany), or the Self-Adjusting File (ReDent-Nova, Ra'anana, Israel). The apical root surface and horizontal sections 2, 4, and 6 mm from the apex were observed under a microscope. The presence of cracks was noted. The chi-square test was performed to compare the appearance of cracked roots between the experimental groups. No cracks were found in the control teeth and teeth instrumented with the Self-Adjusting File. Cracks were found in 10 of 20 (50%), 7 of 20 (35%), and 1 of 20 (5%) teeth after canal instrumentation with the ProTaper, OneShape, and Reciproc files, respectively. The difference between the experimental groups was statistically significant (P File and Reciproc files caused less cracks than the ProTaper and OneShape files. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  18. Prioritizing quantitative trait loci for root system architecture in tetraploid wheat.

    Science.gov (United States)

    Maccaferri, Marco; El-Feki, Walid; Nazemi, Ghasemali; Salvi, Silvio; Canè, Maria Angela; Colalongo, Maria Chiara; Stefanelli, Sandra; Tuberosa, Roberto

    2016-02-01

    Optimization of root system architecture (RSA) traits is an important objective for modern wheat breeding. Linkage and association mapping for RSA in two recombinant inbred line populations and one association mapping panel of 183 elite durum wheat (Triticum turgidum L. var. durum Desf.) accessions evaluated as seedlings grown on filter paper/polycarbonate screening plates revealed 20 clusters of quantitative trait loci (QTLs) for root length and number, as well as 30 QTLs for root growth angle (RGA). Divergent RGA phenotypes observed by seminal root screening were validated by root phenotyping of field-grown adult plants. QTLs were mapped on a high-density tetraploid consensus map based on transcript-associated Illumina 90K single nucleotide polymorphisms (SNPs) developed for bread and durum wheat, thus allowing for an accurate cross-referencing of RSA QTLs between durum and bread wheat. Among the main QTL clusters for root length and number highlighted in this study, 15 overlapped with QTLs for multiple RSA traits reported in bread wheat, while out of 30 QTLs for RGA, only six showed co-location with previously reported QTLs in wheat. Based on their relative additive effects/significance, allelic distribution in the association mapping panel, and co-location with QTLs for grain weight and grain yield, the RSA QTLs have been prioritized in terms of breeding value. Three major QTL clusters for root length and number (RSA_QTL_cluster_5#, RSA_QTL_cluster_6#, and RSA_QTL_cluster_12#) and nine RGA QTL clusters (QRGA.ubo-2A.1, QRGA.ubo-2A.3, QRGA.ubo-2B.2/2B.3, QRGA.ubo-4B.4, QRGA.ubo-6A.1, QRGA.ubo-6A.2, QRGA.ubo-7A.1, QRGA.ubo-7A.2, and QRGA.ubo-7B) appear particularly valuable for further characterization towards a possible implementation of breeding applications in marker-assisted selection and/or cloning of the causal genes underlying the QTLs. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  19. Endodontic Treatment of Maxillary Premolar with Three Root Canals Using Optical Microscope and NiTi Rotatory Files System.

    Science.gov (United States)

    Relvas, João Bosco Formiga; de Carvalho, Fredsom Marcio Acris; Marques, André Augusto Franco; Sponchiado, Emílio Carlos; Garcia, Lucas da Fonseca Roberti

    2013-01-01

    The aim of the study was to report a clinical case of endodontic treatment of a maxillary first premolar with three root canals using an optical microscope and rotary instrumentation technique. The main complaint of the patient, a 16-year-old girl, was pain in tooth 14. After clinical and radiographic examination, irreversible pulpitis was diagnosed. An alteration in the middle third of the pulp chamber radiographically observed suggested the presence of three root canals. Pulp chamber access and initial catheterization using size number 10 K-files were performed. The optical microscope and radiographic examination were used to confirm the presence of three root canals. PathFiles #13, #16, and #19 were used to perform catheterization and ProTaper files S1 and S2 for cervical preparation. Apical preparation was performed using F1 file in the buccal canals and F2 in the palatal canal up to the working length. The root canals were filled with Endofill sealer by thermal compaction technique using McSpadden #50. The case has been receiving follow-up for 12 months and no painful symptomatology or periapical lesions have been found. The use of technological tools was able to assist the endodontic treatment of teeth with complex internal anatomy, such as three-canal premolars.

  20. Fruit yield and root system distribution of 'Tommy Atkins' mango under different irrigation regimes

    Directory of Open Access Journals (Sweden)

    Marcelo R. dos Santos

    2014-04-01

    Full Text Available This study aimed to evaluate the fruit yield and the distribution of 'Tommy Atkins' mango root system under different irrigation regimes in the semiarid region of Bahia. The experimental design was completely randomized with five treatments and three replicates: 1 - Irrigation supplying 100% of ETc in phases I, II and III; 2 - Regulated deficit irrigation (RDI supplying 50% of ETc in phase I (beginning of flowering to early fruit growth; 3 - RDI supplying 50% ETc in phase II (start of expansion until the beginning of physiological maturity; 4 - RDI supplying 50% ETc in phase III (physiological mature fruits; 5 - No irrigation during all three phases. The regulated deficit irrigation supplying 50% of the ETc during phase I and II provided larger root length density of 'Tommy Atkins' mango. Regardless of management strategy, the roots were developed in all evaluated soil volume and the highest density is concentrated from 0.50 to 1.50 m distance from the trunk and in 0.20 to 0.90 m depth in the soil, that suggests this region to be the best place for fertilizer application as well for soil water sensor placement. The application of RDI during fruit set does not influence either root distribution or production. Root system and crop production is significantly reduced under no irrigation conditions.

  1. CLE-CLAVATA1 peptide-receptor signaling module regulates the expansion of plant root systems in a nitrogen-dependent manner.

    Science.gov (United States)

    Araya, Takao; Miyamoto, Mayu; Wibowo, Juliarni; Suzuki, Akinori; Kojima, Soichi; Tsuchiya, Yumiko N; Sawa, Shinichiro; Fukuda, Hiroo; von Wirén, Nicolaus; Takahashi, Hideki

    2014-02-04

    Morphological plasticity of root systems is critically important for plant survival because it allows plants to optimize their capacity to take up water and nutrients from the soil environment. Here we show that a signaling module composed of nitrogen (N)-responsive CLE (CLAVATA3/ESR-related) peptides and the CLAVATA1 (CLV1) leucine-rich repeat receptor-like kinase is expressed in the root vasculature in Arabidopsis thaliana and plays a crucial role in regulating the expansion of the root system under N-deficient conditions. CLE1, -3, -4, and -7 were induced by N deficiency in roots, predominantly expressed in root pericycle cells, and their overexpression repressed the growth of lateral root primordia and their emergence from the primary root. In contrast, clv1 mutants showed progressive outgrowth of lateral root primordia into lateral roots under N-deficient conditions. The clv1 phenotype was reverted by introducing a CLV1 promoter-driven CLV1:GFP construct producing CLV1:GFP fusion proteins in phloem companion cells of roots. The overaccumulation of CLE2, -3, -4, and -7 in clv1 mutants suggested the amplitude of the CLE peptide signals being feedback-regulated by CLV1. When CLE3 was overexpressed under its own promoter in wild-type plants, the length of lateral roots was negatively correlated with increasing CLE3 mRNA levels; however, this inhibitory action of CLE3 was abrogated in the clv1 mutant background. Our findings identify the N-responsive CLE-CLV1 signaling module as an essential mechanism restrictively controlling the expansion of the lateral root system in N-deficient environments.

  2. Earthworm activity and decomposition of 14C-labelled grass root systems

    NARCIS (Netherlands)

    Uyl, A.; Didden, W.A.M.; Marinussen, J.

    2002-01-01

    Decomposition of 14C-labelled root systems of the grass species Holcus lanatus and Festuca ovina, representative of mesotrophic and oligotrophic situations, respectively, was monitored during 14 months under field conditions in the presence or absence of earthworms (Lumbricus rubellus). During the

  3. Influence of Root Exudates and Soil on Attachment of Pasteuria penetrans to Meloidogyne arenaria.

    Science.gov (United States)

    Liu, Chang; Timper, Patricia; Ji, Pingsheng; Mekete, Tesfamariam; Joseph, Soumi

    2017-09-01

    The bacterium Pasteuria penetrans is a parasite of root-knot nematodes ( Meloidogyne spp.). Endospores of P. penetrans attach to the cuticle of second-stage juveniles (J2) and subsequently sterilize infected females. When encumbered by large numbers of spores, juveniles are less mobile and their ability to infect roots is reduced. This study looked at different factors that influence spore attachment of P. penetrans to the root-knot nematode Meloidogyne arenaria . Pretreatment of J2 with root exudates of eggplant ( Solanum melongena cv. Black beauty) reduced spore attachment compared with pretreatment with phosphate-buffered saline (PBS), suggesting that the nematode surface coat was altered or the spore recognition domains on the nematode surface were blocked. Spore attachment was equally reduced following exposure to root exudates from both host and nonhost plants for M. arenaria , indicating a common signal that affects spore attachment. Although phytohormones have been shown to influence the lipophilicity of the nematode surface coat, auxins and kinetins did not affect spore attachment compared with PBS. Root exudates reduced spore attachment more in sterilized soil than in natural soil. Sterilization may have eliminated microbes that consume root exudates, or altered the chemical components of the soil solution or root exudates. Root exudates caused a greater decrease in spore attachment in loamy sand than in a sandy loam soil. The sandy loam had higher clay content than the loamy sand, which may have resulted in more adsorption of compounds in the root exudates that affect spore attachment. The components of the root exudates could have also been modified by soil type. The results of this study demonstrate that root exudates can decrease the attachment of P. penetrans endospores to root-knot nematodes, indicating that when these nematodes enter the root zone their susceptibility to spore attachment may decrease.

  4. Establishment of Aquilaria malaccensis Callus, cell suspension and adventitious root systems

    International Nuclear Information System (INIS)

    Norazlina Noordin; Rusli Ibrahim

    2010-01-01

    Aquilaria malaccensis is a tropical forest tree from the family Thymelaeaceae, an endangered forest species and was listed in CITES since 1995. Locally known as Pokok Karas, this tree produces agar wood or gaharu, a highly valuable, resinous and fragrant forest product. Karas has been highly recognized for its vast medicinal values and gaharu has been widely use for perfumery, incense and religious purposes. The phyto chemical studies of agar wood showed that Sesqui terpenoid and Phenyl ethy chromone derivatives are the principal compounds that have anti allergic and anti microbe activities. Cell and organ culture systems provide large scale production of biomass and offers feasibilities for the production of secondary metabolites. This paper describes the work done for establishing reproducible systems for callus initiation and production of cell suspension cultures as well as production of adventitious roots that will later be amenable for the production of secondary metabolites of A. malaccensis. Hence, further manipulation with Methyl Jasmonate, a chemical elicitor could be done to induce secondary metabolites using callus, cell suspension and adventitious roots systems. (author)

  5. Root Resorption with Orthodontic Mechanics: Pertinent Areas Revisited.

    Science.gov (United States)

    Krishnan, V

    2017-03-01

    Root resorption can occur at any time during orthodontic treatment and lead to a compromise in the prognosis of the tooth and the stability of the treatment results. Recent research has focused more on the cause and effect relationship as well as preventive or treatment options to combat this unwelcome event. Investigations have highlighted the genetic as well as molecular aspects of the process and enabled clinicians to determine which patients might be susceptible. A proper medical history, an assessment of predisposing factors, a radiographic evaluation for alterations in root morphology and careful planning and execution of orthodontic mechanics may reduce the incidence of root resorption. The current review is aimed at providing clinicians and academics with an insight into the process of root resorption, the methods of identification during its early stages and intervention at the right time to reduce its severity. © 2017 Australian Dental Association.

  6. Rhizosphere microbial community structure in relation to root location and plant iron nutritional status.

    Science.gov (United States)

    Yang, C H; Crowley, D E

    2000-01-01

    Root exudate composition and quantity vary in relation to plant nutritional status, but the impact of the differences on rhizosphere microbial communities is not known. To examine this question, we performed an experiment with barley (Hordeum vulgare) plants under iron-limiting and iron-sufficient growth conditions. Plants were grown in an iron-limiting soil in root box microcosms. One-half of the plants were treated with foliar iron every day to inhibit phytosiderophore production and to alter root exudate composition. After 30 days, the bacterial communities associated with different root zones, including the primary root tips, nonelongating secondary root tips, sites of lateral root emergence, and older roots distal from the tip, were characterized by using 16S ribosomal DNA (rDNA) fingerprints generated by PCR-denaturing gradient gel electrophoresis (DGGE). Our results showed that the microbial communities associated with the different root locations produced many common 16S rDNA bands but that the communities could be distinguished by using correspondence analysis. Approximately 40% of the variation between communities could be attributed to plant iron nutritional status. A sequence analysis of clones generated from a single 16S rDNA band obtained at all of the root locations revealed that there were taxonomically different species in the same band, suggesting that the resolving power of DGGE for characterization of community structure at the species level is limited. Our results suggest that the bacterial communities in the rhizosphere are substantially different in different root zones and that a rhizosphere community may be altered by changes in root exudate composition caused by changes in plant iron nutritional status.

  7. An information transfer based novel framework for fault root cause tracing of complex electromechanical systems in the processing industry

    Science.gov (United States)

    Wang, Rongxi; Gao, Xu; Gao, Jianmin; Gao, Zhiyong; Kang, Jiani

    2018-02-01

    As one of the most important approaches for analyzing the mechanism of fault pervasion, fault root cause tracing is a powerful and useful tool for detecting the fundamental causes of faults so as to prevent any further propagation and amplification. Focused on the problems arising from the lack of systematic and comprehensive integration, an information transfer-based novel data-driven framework for fault root cause tracing of complex electromechanical systems in the processing industry was proposed, taking into consideration the experience and qualitative analysis of conventional fault root cause tracing methods. Firstly, an improved symbolic transfer entropy method was presented to construct a directed-weighted information model for a specific complex electromechanical system based on the information flow. Secondly, considering the feedback mechanisms in the complex electromechanical systems, a method for determining the threshold values of weights was developed to explore the disciplines of fault propagation. Lastly, an iterative method was introduced to identify the fault development process. The fault root cause was traced by analyzing the changes in information transfer between the nodes along with the fault propagation pathway. An actual fault root cause tracing application of a complex electromechanical system is used to verify the effectiveness of the proposed framework. A unique fault root cause is obtained regardless of the choice of the initial variable. Thus, the proposed framework can be flexibly and effectively used in fault root cause tracing for complex electromechanical systems in the processing industry, and formulate the foundation of system vulnerability analysis and condition prediction, as well as other engineering applications.

  8. 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.

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

    Science.gov (United States)

    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 the questions of how auxin and cytokinin govern fern root system architecture and whether this can tell us something about the origin of that root. Using Azolla filiculoides, we characterized the influence of IAA and zeatin on adventitious fern root meristems and vasculature by Nomarski microscopy. Simultaneously, RNAseq analyses, yielding 36,091 contigs, were used to uncover how the phytohormones affect root tip gene expression. We show that auxin restricts Azolla root meristem development, while cytokinin promotes it; it is the opposite effect of what is observed in Arabidopsis. Global gene expression profiling uncovered 145 genes significantly regulated by cytokinin or auxin, including cell wall modulators, cell division regulators and lateral root formation coordinators. Our data illuminate both evolution and development of fern roots. Promotion of meristem size through cytokinin supports the idea that root meristems of euphyllophytes evolved from shoot meristems. The foundation of these roots was laid in a postembryonically branching shoot system. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  10. Deep Roots? Behavioral Inhibition and Behavioral Activation System (BIS/BAS) Sensitivity and Entrepreneurship

    NARCIS (Netherlands)

    Lerner, Daniel; Hatak, Isabella; Rauch, Andreas

    2018-01-01

    A growing number of studies suggest a link between disinhibition and entrepreneurship. Separately, psychology literature has theorized and empirically shown that the roots of disinhibition can largely be traced to two psychophysiological systems – the behavioral inhibition system (BIS) and

  11. Development and optimization of hairy root culture systems in ...

    African Journals Online (AJOL)

    Transformation of Withania somnifera was carried out by using three Agrobacterium rhizogenes strains (ATCC 15834, R1000 and K599) for hairy root induction. Induction of hairy root was carried out in leaf, petiole and internodal explants. Hairy root induction was successful only in ATCC 15834 and R1000. The highest ...

  12. Cotton growth potassium deficiency stress is influenced by photosynthetic apparatus and root system

    International Nuclear Information System (INIS)

    Hussain, Z.U.; Arshad, M.

    2010-01-01

    Due to rapid depletion of soil potassium (K) and increasing cost of K fertilizers in Pakistan, the K-use efficient crop genotypes become very important for agricultural sustain ability. However, limited research has been done on this important issue particularly in cotton, an important fibre crop. We studied the growth and biomass production of three cotton genotypes (CIM-506, NIAB- 78 and NIBGE-2) different in K-use efficiency in a K-deficient solution culture. Genotypes differed significantly for biomass production, absolute growth rates (shoot, root, leaf, total), leaf area, mean leaf area and relative growth rate of leaf under K deficiency stress, besides specific leaf area. The relative growth rate (shoot, root, total) did not differ significantly, except for leaf. For all these characters, NIBGE-2 was the best performer followed by NIAB-78 and CIM-506. Shoot dry weight was significantly related with (in decreasing order of significance): mean leaf area, leaf dry weight, leaf area, root dry weight, absolute growth rate of shoot, absolute growth rate of root, absolute growth rate total, absolute growth rate root, relative growth rate leaf, relative growth rate total and relative growth rate shoot. Hence, the enhanced biomass accumulation of cotton genotypes under K deficiency stress is related to their efficient photosynthetic apparatus and root system, appeared to be the most important morphological markers while breeding for K-use efficient cotton genotypes.(author)

  13. archiDART v3.0: A new data analysis pipeline allowing the topological analysis of plant root systems.

    Science.gov (United States)

    Delory, Benjamin M; Li, Mao; Topp, Christopher N; Lobet, Guillaume

    2018-01-01

    Quantifying plant morphology is a very challenging task that requires methods able to capture the geometry and topology of plant organs at various spatial scales. Recently, the use of persistent homology as a mathematical framework to quantify plant morphology has been successfully demonstrated for leaves, shoots, and root systems. In this paper, we present a new data analysis pipeline implemented in the R package archiDART to analyse root system architectures using persistent homology. In addition, we also show that both geometric and topological descriptors are necessary to accurately compare root systems and assess their natural complexity.

  14. Switchgrass ecotypes alter microbial contribution to deep-soil C

    Science.gov (United States)

    Roosendaal, Damaris; Stewart, Catherine E.; Denef, Karolien; Follett, Ronald F.; Pruessner, Elizabeth; Comas, Louise H.; Varvel, Gary E.; Saathoff, Aaron; Palmer, Nathan; Sarath, Gautam; Jin, Virginia L.; Schmer, Marty; Soundararajan, Madhavan

    2016-05-01

    Switchgrass (Panicum virgatum L.) is a C4, perennial grass that is being developed as a bioenergy crop for the United States. While aboveground biomass production is well documented for switchgrass ecotypes (lowland, upland), little is known about the impact of plant belowground productivity on microbial communities down deep in the soil profiles. Microbial dynamics in deeper soils are likely to exert considerable control on ecosystem services, including C and nutrient cycles, due to their involvement in such processes as soil formation and ecosystem biogeochemistry. Differences in root biomass and rooting characteristics of switchgrass ecotypes could lead to distinct differences in belowground microbial biomass and microbial community composition. We quantified root abundance and root architecture and the associated microbial abundance, composition, and rhizodeposit C uptake for two switchgrass ecotypes using stable-isotope probing of microbial phospholipid fatty acids (PLFAs) after 13CO2 pulse-chase labeling. Kanlow, a lowland ecotype with thicker roots, had greater plant biomass above- and belowground (g m-2), greater root mass density (mg cm-3), and lower specific root length (m g-1) compared to Summer, an upland ecotype with finer root architecture. The relative abundance of bacterial biomarkers dominated microbial PLFA profiles for soils under both Kanlow and Summer (55.4 and 53.5 %, respectively; P = 0.0367), with differences attributable to a greater relative abundance of Gram-negative bacteria in soils under Kanlow (18.1 %) compared to soils under Summer (16.3 %; P = 0.0455). The two ecotypes also had distinctly different microbial communities process rhizodeposit C: greater relative atom % 13C excess in Gram-negative bacteria (44.1 ± 2.3 %) under the thicker roots of Kanlow and greater relative atom % 13C excess in saprotrophic fungi under the thinner roots of Summer (48.5 ± 2.2 %). For bioenergy production systems, variation between switchgrass

  15. Endodontic management of C-shaped root canal system of mandibular first molar by using a modified technique of self-adjusting file system.

    Science.gov (United States)

    Helvacioglu-Yigit, Dilek

    2015-01-01

    C-shaped canal system is a seldom-found root canal anatomy which displays a challenge in all stages of endodontic treatment. According to the literature, this type of canal morphology is not a common finding in the mandibular first molar teeth. This case report presents endodontic management of a mandibular first molar with a C-shaped canal system. Root canal system was cleaned and shaped by nickel-titanium (NiTi) rotary instruments combined with self-adjusting file (SAF). Obturation was performed using warm, vertical condensation combined with the injection of warm gutta-percha. Follow-up examination 12 months later showed that the tooth was asymptomatic. The radiological findings presented no signs of periapical pathology. The clinician must be aware of the occurence and complexity of C-shaped canals in mandibular first molar teeth to perform a successful root canal treatment. The supplementary use of SAF after application of rotary instruments in C-shaped root canals might be a promising approach in endodontic treatment of this type of canal morphology.

  16. Comparison between Arabidopsis and Rice for Main Pathways of K(+) and Na(+) Uptake by Roots.

    Science.gov (United States)

    Nieves-Cordones, Manuel; Martínez, Vicente; Benito, Begoña; Rubio, Francisco

    2016-01-01

    K(+) is an essential macronutrient for plants. It is acquired by specific uptake systems located in roots. Although the concentrations of K(+) in the soil solution are widely variable, K(+) nutrition is secured by uptake systems that exhibit different affinities for K(+). Two main systems have been described for root K(+) uptake in several species: the high-affinity HAK5-like transporter and the inward-rectifier AKT1-like channel. Other unidentified systems may be also involved in root K(+) uptake, although they only seem to operate when K(+) is not limiting. The use of knock-out lines has allowed demonstrating their role in root K(+) uptake in Arabidopsis and rice. Plant adaptation to the different K(+) supplies relies on the finely tuned regulation of these systems. Low K(+)-induced transcriptional up-regulation of the genes encoding HAK5-like transporters occurs through a signal cascade that includes changes in the membrane potential of root cells and increases in ethylene and reactive oxygen species concentrations. Activation of AKT1 channels occurs through phosphorylation by the CIPK23/CBL1 complex. Recently, activation of the Arabidopsis HAK5 by the same complex has been reported, pointing to CIPK23/CBL as a central regulator of the plant's adaptation to low K(+). Na(+) is not an essential plant nutrient but it may be beneficial for some plants. At low concentrations, Na(+) improves growth, especially under K(+) deficiency. Thus, high-affinity Na(+) uptake systems have been described that belong to the HKT and HAK families of transporters. At high concentrations, typical of saline environments, Na(+) accumulates in plant tissues at high concentrations, producing alterations that include toxicity, water deficit and K(+) deficiency. Data concerning pathways for Na(+) uptake into roots under saline conditions are still scarce, although several possibilities have been proposed. The apoplast is a significant pathway for Na(+) uptake in rice grown under salinity

  17. Comparison between Arabidopsis and Rice for Main Pathways of K+ and Na+ Uptake by Roots

    Science.gov (United States)

    Nieves-Cordones, Manuel; Martínez, Vicente; Benito, Begoña; Rubio, Francisco

    2016-01-01

    K+ is an essential macronutrient for plants. It is acquired by specific uptake systems located in roots. Although the concentrations of K+ in the soil solution are widely variable, K+ nutrition is secured by uptake systems that exhibit different affinities for K+. Two main systems have been described for root K+ uptake in several species: the high-affinity HAK5-like transporter and the inward-rectifier AKT1-like channel. Other unidentified systems may be also involved in root K+ uptake, although they only seem to operate when K+ is not limiting. The use of knock-out lines has allowed demonstrating their role in root K+ uptake in Arabidopsis and rice. Plant adaptation to the different K+ supplies relies on the finely tuned regulation of these systems. Low K+-induced transcriptional up-regulation of the genes encoding HAK5-like transporters occurs through a signal cascade that includes changes in the membrane potential of root cells and increases in ethylene and reactive oxygen species concentrations. Activation of AKT1 channels occurs through phosphorylation by the CIPK23/CBL1 complex. Recently, activation of the Arabidopsis HAK5 by the same complex has been reported, pointing to CIPK23/CBL as a central regulator of the plant’s adaptation to low K+. Na+ is not an essential plant nutrient but it may be beneficial for some plants. At low concentrations, Na+ improves growth, especially under K+ deficiency. Thus, high-affinity Na+ uptake systems have been described that belong to the HKT and HAK families of transporters. At high concentrations, typical of saline environments, Na+ accumulates in plant tissues at high concentrations, producing alterations that include toxicity, water deficit and K+ deficiency. Data concerning pathways for Na+ uptake into roots under saline conditions are still scarce, although several possibilities have been proposed. The apoplast is a significant pathway for Na+ uptake in rice grown under salinity conditions, but in other plant species

  18. Primary root protophloem differentiation requires balanced phosphatidylinositol-4,5-biphosphate levels and systemically affects root branching.

    OpenAIRE

    Rodriguez-Villalon Antia; Gujas Bojan; van Wijk Ringo; Munnik Teun; Hardtke Christian S

    2015-01-01

    Protophloem is a specialized vascular tissue in growing plant organs, such as root meristems. In Arabidopsis mutants with impaired primary root protophloem differentiation, brevis radix (brx) and octopus (ops), meristematic activity and consequently overall root growth are strongly reduced. Second site mutation in the protophloem-specific presumed phosphoinositide 5-phosphatase cotyledon vascular pattern 2 (CVP2), but not in its homolog CVP2-like 1 (CVL1), partially rescues brx defects. Consi...

  19. Mineralization and hydrothermal alteration of the Tajroud vein system, south of Neyshabour

    Directory of Open Access Journals (Sweden)

    Mohsen Alikhani Banghani

    2013-10-01

    Full Text Available The Tajroud vein system is located 190 km southwest of Mashhad, and in the southern part of the Sabzevar zone. The vein host rocks consist of Eocene intermediate to silicic volcanic rocks. The mineralization occurs as open space filling, taking place as veins, veinlets and hydrothermal breccias. Based on field geology and textural evidence, three main stages of mineralization were identified. Stage I mainly contains quartz, pyrite, chalcopyrite and magnetite. Stage II, which has the same mineral assemblage as stage I, is the most important stage in terms of volume. Finally, stage III is characterized by repetitive quartz and calcite banding with negligible amounts of sulfide minerals. Hydrothermal alteration is developed around the veins and tends to be more intense in the vicinity of the veins. The plot of the Ishikawa alteration index (AI versus chlorite-carbonate-pyrite index (CCPI, known as alteration box plot, displays three main alteration trends. The hydrothermal alteration assemblage of quartz, adularia, chlorite, illite, calcite, and epidote that envelops the Tajroud vein system formed from the upwelling of near-neutral to weakly alkaline hydrothermal solutions. The mineralogic, alteration and geochemical characteristics of the studied area and comparison with epithermal ore deposits indicate that the Tajroud vein system represents an epithermal system of low-sulfidation type.

  20. Composite potato plants with transgenic roots on non-transgenic shoots: a model system for studying gene silencing in roots

    DEFF Research Database (Denmark)

    Horn, Patricia; Santala, Johanna; Nielsen, Steen Lykke

    2014-01-01

    induced phenotypically normal roots which, however, showed a reduced response to cytokinin as compared with non-transgenic roots. Nevertheless, both types of roots were infected to a similar high rate with the zoospores of Spongospora subterranea, a soilborne potato pathogen. The transgenic roots...

  1. Alterations in cytosol free calcium in horseradish roots simultaneously exposed to lanthanum(III) and acid rain.

    Science.gov (United States)

    Zhang, Xuanbo; Wang, Lihong; Zhou, Anhua; Zhou, Qing; Huang, Xiaohua

    2016-04-01

    The extensive use of rare earth elements (REEs) has increased their environmental levels. REE pollution concomitant with acid rain in many agricultural regions can affect crop growth. Cytosol free calcium ions (Ca(2+)) play an important role in almost all cellular activities. However, no data have been reported regarding the role of cytosol free Ca(2+) in plant roots simultaneously exposed to REE and acid rain. In this study, the effects of exposures to lanthanum(III) and acid rain, independently and in combination, on cytosol free Ca(2+) levels, root activity, metal contents, biomass, cytosol pH and La contents in horseradish roots were investigated. The simultaneous exposures to La(III) and acid rain increased or decreased the cytosol free Ca(2+) levels, depending on the concentration of La(III), and these effects were more evident than independent exposure to La(III) or acid rain. In combined exposures, cytosol free Ca(2+) played an important role in the regulation of root activity, metal contents and biomass. These roles were closely related to La(III) dose, acid rain strength and treatment mode (independent exposure or simultaneous exposure). A low concentration of La(III) (20 mg L(-1)) could alleviate the adverse effects on the roots caused by acid rain, and the combined exposures at higher concentrations of La(III) and acid rain had synergic effects on the roots. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Vertical distribution of the root system of linseed (Linum usitatissimum L. and legumes in pure and mixed sowing

    Directory of Open Access Journals (Sweden)

    Agnieszka Klimek-Kopyra

    2015-03-01

    Full Text Available Root competition for below-ground resources between edible plants may provide for long-term sustainability of agriculture systems. Intercropping can be more productive than a pure crop due to taking advantage of the morphological differences between species. In pure cropping, all biophysical interactions between plants occur through soil conditions. In intercropping, competition for water and nutrients is of major importance, but if the roots of one species occupy the zone just underneath the roots of the other crop, they can better use the resources of the root zone of the crop. The root system demonstrates a high degree of plasticity in its development in response to local heterogeneity of the soil profile and plant density. This study aimed at determining: (i the morphological characteristics of the root systems of linseed, pea and vetch depending on the method of sowing; (ii the root distribution in various soil types and at different soil profile depths (0–15 cm, 15–30 cm. Two three-year field experiments were conducted on two soil types in south Poland: soil A – Luvic Phaeozem (s1 and soil B – Eutric Cambisol (s2. These results show that linseed was more aggressive toward both legumes in mixture, but it produced lower yield compared to pure cropping. The environmental stress of plants in mixtures increased the relative weight of roots, which resulted in decreasing the root-shoot ratio (RSR.

  3. Regrowth of Cirsium arvense from intact roots and root fragments at different soil depths

    Directory of Open Access Journals (Sweden)

    Thomsen, Mette Goul

    2014-02-01

    Full Text Available In the present work we measured the shoot rate from intact roots and from root fragments of Cirsium arvense at different digging depths and the number of leaves were used as estimate of minimum regenerative capacity. The experiments were performed on four sites with three or four repetitions of each treatment. On each site plot, the soil was removed down to a given depth within a 1 x 1 m square. All plant parts was excavated from the soil and the soil was either replaced without any root material, or roots of C. arvense was cut into 10 cm long fragments and replaced into the source hole. Shoot number, aboveground biomass and number of leaves were measured. Digging depth and time explained 50% - 60% of the variation in biomass (P<0.001. Replacement of root fragments increased the shoot number in one out of four treatments but did not affect biomass produced compared to production from undisturbed root systems. Number of leaves showed that shoots from all digging depths passed the level of minimum regenerative capacity. We conclude that the intact root system from all depths was able to regenerate within one season and it has a high contribution to the produced biomass compared with root fragments in the upper soil layers.

  4. The Importance of Juvenile Root Traits for Crop Yields

    Science.gov (United States)

    White, Philip; Adu, Michael; Broadley, Martin; Brown, Lawrie; Dupuy, Lionel; George, Timothy; Graham, Neil; Hammond, John; Hayden, Rory; Neugebauer, Konrad; Nightingale, Mark; Ramsay, Gavin; Thomas, Catherine; Thompson, Jacqueline; Wishart, Jane; Wright, Gladys

    2014-05-01

    Genetic variation in root system architecture (RSA) is an under-exploited breeding resource. This is partly a consequence of difficulties in the rapid and accurate assessment of subterranean root systems. However, although the characterisation of root systems of large plants in the field are both time-consuming and labour-intensive, high-throughput (HTP) screens of root systems of juvenile plants can be performed in the field, glasshouse or laboratory. It is hypothesised that improving the root systems of juvenile plants can accelerate access to water and essential mineral elements, leading to rapid crop establishment and, consequently, greater yields. This presentation will illustrate how aspects of the juvenile root systems of potato (Solanum tuberosum L.) and oilseed rape (OSR; Brassica napus L.) correlate with crop yields and examine the reasons for such correlations. It will first describe the significant positive relationships between early root system development, phosphorus acquisition, canopy establishment and eventual yield among potato genotypes. It will report the development of a glasshouse assay for root system architecture (RSA) of juvenile potato plants, the correlations between root system architectures measured in the glasshouse and field, and the relationships between aspects of the juvenile root system and crop yields under drought conditions. It will then describe the development of HTP systems for assaying RSA of OSR seedlings, the identification of genetic loci affecting RSA in OSR, the development of mathematical models describing resource acquisition by OSR, and the correlations between root traits recorded in the HTP systems and yields of OSR in the field.

  5. Root and Nodulation Phenotypes of the Ethylene-Insensitive Sickle Mutant of Medicago truncatula

    Directory of Open Access Journals (Sweden)

    JOKO PRAYITNO

    2010-09-01

    Full Text Available The sickle (skl mutant of the model legume Medicago truncatula is an ethylene-sensitive mutant that have a ten-fold increase in nodule numbers. The nodulation and root phenotypes of the skl mutant were investigated and further characterised. The skl mutant had longer roots than the wild type, but when inoculated with Sinorhizobium, its root length was reduced to the level of wild type. Furthermore, lateral root numbers in uninoculated skl were similar to those in uninoculated wild type. However, when the root tips were decapitated, fewer lateral roots formed in skl than in wild type. Nodule numbers of the skl mutant were significantly reduced by low nitrate concentration (2.5 mM. These results suggest that skl mutant has alterations in both root and nodule development.

  6. Systemic allergic dermatitis caused by Apiaceae root vegetables

    DEFF Research Database (Denmark)

    Paulsen, Evy; Petersen, Thomas H; Fretté, Xavier C

    2014-01-01

    Immediate hypersensitivity reactions to root vegetables of the Umbelliferae plant family (Apiaceae) is well known. Delayed-type hypersensitivity is rarely reported.......Immediate hypersensitivity reactions to root vegetables of the Umbelliferae plant family (Apiaceae) is well known. Delayed-type hypersensitivity is rarely reported....

  7. Root profile in Multi-layered Dehesas: an approach to plant-to-plant Interaction

    Science.gov (United States)

    Rolo, V.; Moreno, G.

    2009-04-01

    Assessing plant-to-plant relationship is a key issue in agroforestry systems. Due to the sessile feature of plants most of these interactions take place within a restricted space, so characterizing the zone where the plant alters its environment is important to find overlapping areas where the facilitation or competition could occur. Main part of plan-to-plant interactions in the dehesa are located at belowground level, thus the main limited resources in Mediterranean ecosystems are soil nutrient and water. Hence a better knowledge of rooting plant profile can be useful to understand the functioning of the dehesa. The Iberian dehesa has always been considered as a silvopastoral system where, at least, two strata of vegetation coexist: native grasses and trees. However the dehesa is also a diverse system where cropland and encroached territories have been systematically combined, more or less periodically, with native pasture in order to obtain agricultural, pastoral and forestry outputs. These multipurpose mosaic-type systems generate several scenarios where the plant influence zone may be overlapped and the interaction, competition or facilitation, between plants can play an important role in the ecosystem functioning in terms of productivity and stability. In the present study our aim was to characterize the rooting profile of multi-layered dehesas in order to understand the competitive, and/or facilitative, relationships within the different plant strata. The root profile of Quercus ilex subsp. ballota, Cistus ladanifer, Retama spaherocarpa and natural grasses was studied. So 48 trenches, up to 2 meters deep, were excavated in 4 different environments: (i) grass; (ii) tree-grass; (iii) tree-shrub and (iv) tree-shrub-grass (12 trenches in each environment). The study was carried out in 4 dehesas, 2 encroached with C. ladanifer and 2 with R. spaherocarpa. In every trench soil samples were taken each 20 cm. Subsequently, all samples were sieved using different mesh

  8. Mechanics of integrating root causes into PRAs

    International Nuclear Information System (INIS)

    Bruske, S.Z.; Cadwallader, L.C.; Stepina, P.L.; Vesely, W.E.

    1985-01-01

    This paper presents a derivation of root cause importance, root cause data for selected components of a pressurized water reactor auxiliary feedwater system, an Accident Sequence Evaluation Program (ASEP) auxiliary feedwater system model, and the results of root cause importance calculations. The methodology shown herein is straightforward and is easily applied to existing probabilistic risk assessments. Root cause importance can greatly benefit the areas of design, maintenance, and inspection. Root cause importance for various components and circumstances can be evaluated

  9. QTL meta-analysis of root traits in Brassica napus under contrasting phosphorus supply in two growth systems.

    Science.gov (United States)

    Zhang, Ying; Thomas, Catherine L; Xiang, Jinxia; Long, Yan; Wang, Xiaohua; Zou, Jun; Luo, Ziliang; Ding, Guangda; Cai, Hongmei; Graham, Neil S; Hammond, John P; King, Graham J; White, Philip J; Xu, Fangsen; Broadley, Martin R; Shi, Lei; Meng, Jinling

    2016-09-14

    A high-density SNP-based genetic linkage map was constructed and integrated with a previous map in the Tapidor x Ningyou7 (TNDH) Brassica napus population, giving a new map with a total of 2041 molecular markers and an average marker density which increased from 0.39 to 0.97 (0.82 SNP bin) per cM. Root and shoot traits were screened under low and 'normal' phosphate (Pi) supply using a 'pouch and wick' system, and had been screened previously in an agar based system. The P-efficient parent Ningyou7 had a shorter primary root length (PRL), greater lateral root density (LRD) and a greater shoot biomass than the P-inefficient parent Tapidor under both treatments and growth systems. Quantitative trait loci (QTL) analysis identified a total of 131 QTL, and QTL meta-analysis found four integrated QTL across the growth systems. Integration reduced the confidence interval by ~41%. QTL for root and shoot biomass were co-located on chromosome A3 and for lateral root emergence were co-located on chromosomes A4/C4 and C8/C9. There was a major QTL for LRD on chromosome C9 explaining ~18% of the phenotypic variation. QTL underlying an increased LRD may be a useful breeding target for P uptake efficiency in Brassica.

  10. Hairy roots of Helianthus annuus: a model system to study phytoremediation of tetracycline and oxytetracycline.

    Science.gov (United States)

    Gujarathi, Ninad P; Haney, Bryan J; Park, Heidi J; Wickramasinghe, S Ranil; Linden, James C

    2005-01-01

    The release of antibiotics to the environment has to be controlled because of serious threats to human health. Hairy root cultures of Helianthus annuus (sunflower), along with their inherent rhizospheric activity, provide a fast growing, microbe-free environment for understanding plant-pollutant interactions. The root system catalyzes rapid disappearance of tetracycline (TC) and oxytetracycline (OTC) from aqueous media, which suggests roots have potential for phytoremediation of the two antibiotics in vivo. In addition, in vitro modifications of the two antibiotics by filtered, cell- and microbe-free root exudates suggest involvement of root-secreted compounds. The modification is confirmed from changes observed in UV spectra of exudate-treated OTC. Modification appears to be more dominant at the BCD chromophore of the antibiotic molecule. Kinetic analyses dismiss direct enzyme catalysis; the modification rates decrease with increasing OTC concentrations. The rates increase with increasing age of cultures from which root exudates are prepared. The decrease in modification rates upon addition of the antioxidant ascorbic acid (AA) suggests involvement of reactive oxygen species (ROS) in the antibiotic modification process.

  11. 3D Ground Penetrating Radar to Detect Tree Roots and Estimate Root Biomass in the Field

    Directory of Open Access Journals (Sweden)

    Shiping Zhu

    2014-06-01

    Full Text Available The objectives of this study were to detect coarse tree root and to estimate root biomass in the field by using an advanced 3D Ground Penetrating Radar (3D GPR system. This study obtained full-resolution 3D imaging results of tree root system using 500 MHz and 800 MHz bow-tie antennas, respectively. The measurement site included two larch trees, and one of them was excavated after GPR measurements. In this paper, a searching algorithm, based on the continuity of pixel intensity along the root in 3D space, is proposed, and two coarse roots whose diameters are more than 5 cm were detected and delineated correctly. Based on the detection results and the measured root biomass, a linear regression model is proposed to estimate the total root biomass in different depth ranges, and the total error was less than 10%. Additionally, based on the detected root samples, a new index named “magnitude width” is proposed to estimate the root diameter that has good correlation with root diameter compared with other common GPR indexes. This index also provides direct measurement of the root diameter with 13%–16% error, providing reasonable and practical root diameter estimation especially in the field.

  12. Isolation of a novel mutant gene for soil-surface rooting in rice (Oryza sativa L.).

    Science.gov (United States)

    Hanzawa, Eiko; Sasaki, Kazuhiro; Nagai, Shinsei; Obara, Mitsuhiro; Fukuta, Yoshimichi; Uga, Yusaku; Miyao, Akio; Hirochika, Hirohiko; Higashitani, Atsushi; Maekawa, Masahiko; Sato, Tadashi

    2013-11-20

    Root system architecture is an important trait affecting the uptake of nutrients and water by crops. Shallower root systems preferentially take up nutrients from the topsoil and help avoid unfavorable environments in deeper soil layers. We have found a soil-surface rooting mutant from an M2 population that was regenerated from seed calli of a japonica rice cultivar, Nipponbare. In this study, we examined the genetic and physiological characteristics of this mutant. The primary roots of the mutant showed no gravitropic response from the seedling stage on, whereas the gravitropic response of the shoots was normal. Segregation analyses by using an F2 population derived from a cross between the soil-surface rooting mutant and wild-type Nipponbare indicated that the trait was controlled by a single recessive gene, designated as sor1. Fine mapping by using an F2 population derived from a cross between the mutant and an indica rice cultivar, Kasalath, revealed that sor1 was located within a 136-kb region between the simple sequence repeat markers RM16254 and 2935-6 on the terminal region of the short arm of chromosome 4, where 13 putative open reading frames (ORFs) were found. We sequenced these ORFs and detected a 33-bp deletion in one of them, Os04g0101800. Transgenic plants of the mutant transformed with the genomic fragment carrying the Os04g0101800 sequence from Nipponbare showed normal gravitropic responses and no soil-surface rooting. These results suggest that sor1, a rice mutant causing soil-surface rooting and altered root gravitropic response, is allelic to Os04g0101800, and that a 33-bp deletion in the coding region of this gene causes the mutant phenotypes.

  13. Helical growth trajectories in plant roots interacting with stiff barriers

    Science.gov (United States)

    Gerbode, Sharon; Noar, Roslyn; Harrison, Maria

    2009-03-01

    Plant roots successfully navigate heterogeneous soil environments with varying nutrient and water concentrations, as well as a variety of stiff obstacles. While it is thought that the ability of roots to penetrate into a stiff lower soil layer is important for soil erosion, little is known about how a root actually responds to a rigid interface. We have developed a laser sheet imaging technique for recording the 3D growth dynamics of plant roots interacting with stiff barriers. We find that a root encountering an angled interface does not grow in a straight line along the surface, but instead follows a helical trajectory. These experiments build on the pioneering studies of roots grown on a tilted 2D surface, which reported ``root waving,'' a similar curved pattern thought to be caused by the root's sensitivity to both gravity and the rigid surface on which it is grown. Our measurements extend these results to the more physiologically relevant case of 3D growth, where the spiral trajectory can be altered by tuning the relative strengths of the gravity and touch stimuli, providing some intuition for the physical mechanism driving it.

  14. Aetiology, incidence and morphology of the C-shaped root canal system and its impact on clinical endodontics

    Science.gov (United States)

    Kato, A; Ziegler, A; Higuchi, N; Nakata, K; Nakamura, H; Ohno, N

    2014-01-01

    The C-shaped root canal constitutes an unusual root morphology that can be found primarily in mandibular second permanent molars. Due to the complexity of their structure, C-shaped root canal systems may complicate endodontic interventions. A thorough understanding of root canal morphology is therefore imperative for proper diagnosis and successful treatment. This review aims to summarize current knowledge regarding C-shaped roots and root canals, from basic morphology to advanced endodontic procedures. To this end, a systematic search was conducted using the MEDLINE, BIOSIS, Cochrane Library, EMBASE, Google Scholar, Web of Science, PLoS and BioMed Central databases, and many rarely cited articles were included. Furthermore, four interactive 3D models of extracted teeth are introduced that will allow for a better understanding of the complex C-shaped root canal morphology. In addition, the present publication includes an embedded best-practice video showing an exemplary root canal procedure on a tooth with a pronounced C-shaped root canal. The survey of this unusual structure concludes with a number of suggestions concerning future research efforts. PMID:24483229

  15. Unearthing the hidden world of roots: Root biomass and architecture differ among species within the same guild.

    Directory of Open Access Journals (Sweden)

    Katherine Sinacore

    Full Text Available The potential benefits of planting trees have generated significant interest with respect to sequestering carbon and restoring other forest based ecosystem services. Reliable estimates of carbon stocks are pivotal for understanding the global carbon balance and for promoting initiatives to mitigate CO2 emissions through forest management. There are numerous studies employing allometric regression models that convert inventory into aboveground biomass (AGB and carbon (C. Yet the majority of allometric regression models do not consider the root system nor do these equations provide detail on the architecture and shape of different species. The root system is a vital piece toward understanding the hidden form and function roots play in carbon accumulation, nutrient and plant water uptake, and groundwater infiltration. Work that estimates C in forests as well as models that are used to better understand the hydrologic function of trees need better characterization of tree roots. We harvested 40 trees of six different species, including their roots down to 2 mm in diameter and created species-specific and multi-species models to calculate aboveground (AGB, coarse root belowground biomass (BGB, and total biomass (TB. We also explore the relationship between crown structure and root structure. We found that BGB contributes ~27.6% of a tree's TB, lateral roots extend over 1.25 times the distance of crown extent, root allocation patterns varied among species, and that AGB is a strong predictor of TB. These findings highlight the potential importance of including the root system in C estimates and lend important insights into the function roots play in water cycling.

  16. Fine Mapping of QUICK ROOTING 1 and 2, Quantitative Trait Loci Increasing Root Length in Rice.

    Science.gov (United States)

    Kitomi, Yuka; Nakao, Emari; Kawai, Sawako; Kanno, Noriko; Ando, Tsuyu; Fukuoka, Shuichi; Irie, Kenji; Uga, Yusaku

    2018-02-02

    The volume that the root system can occupy is associated with the efficiency of water and nutrient uptake from soil. Genetic improvement of root length, which is a limiting factor for root distribution, is necessary for increasing crop production. In this report, we describe identification of two quantitative trait loci (QTLs) for maximal root length, QUICK ROOTING 1 ( QRO1 ) on chromosome 2 and QRO2 on chromosome 6, in cultivated rice ( Oryza sativa L.). We measured the maximal root length in 26 lines carrying chromosome segments from the long-rooted upland rice cultivar Kinandang Patong in the genetic background of the short-rooted lowland cultivar IR64. Five lines had longer roots than IR64. By rough mapping of the target regions in BC 4 F 2 populations, we detected putative QTLs for maximal root length on chromosomes 2, 6, and 8. To fine-map these QTLs, we used BC 4 F 3 recombinant homozygous lines. QRO1 was mapped between markers RM5651 and RM6107, which delimit a 1.7-Mb interval on chromosome 2, and QRO2 was mapped between markers RM20495 and RM3430-1, which delimit an 884-kb interval on chromosome 6. Both QTLs may be promising gene resources for improving root system architecture in rice. Copyright © 2018 Kitomi et al.

  17. Fine Mapping of QUICK ROOTING 1 and 2, Quantitative Trait Loci Increasing Root Length in Rice

    Directory of Open Access Journals (Sweden)

    Yuka Kitomi

    2018-02-01

    Full Text Available The volume that the root system can occupy is associated with the efficiency of water and nutrient uptake from soil. Genetic improvement of root length, which is a limiting factor for root distribution, is necessary for increasing crop production. In this report, we describe identification of two quantitative trait loci (QTLs for maximal root length, QUICK ROOTING 1 (QRO1 on chromosome 2 and QRO2 on chromosome 6, in cultivated rice (Oryza sativa L.. We measured the maximal root length in 26 lines carrying chromosome segments from the long-rooted upland rice cultivar Kinandang Patong in the genetic background of the short-rooted lowland cultivar IR64. Five lines had longer roots than IR64. By rough mapping of the target regions in BC4F2 populations, we detected putative QTLs for maximal root length on chromosomes 2, 6, and 8. To fine-map these QTLs, we used BC4F3 recombinant homozygous lines. QRO1 was mapped between markers RM5651 and RM6107, which delimit a 1.7-Mb interval on chromosome 2, and QRO2 was mapped between markers RM20495 and RM3430-1, which delimit an 884-kb interval on chromosome 6. Both QTLs may be promising gene resources for improving root system architecture in rice.

  18. Inhibition of histone deacetylation alters Arabidopsis root growth in response to auxin via PIN1 degradation.

    Science.gov (United States)

    Nguyen, Hoai Nguyen; Kim, Jun Hyeok; Jeong, Chan Young; Hong, Suk-Whan; Lee, Hojoung

    2013-10-01

    Our results showed the histone deacetylase inhibitors (HDIs) control root development in Arabidopsis via regulation of PIN1 degradation. Epigenetic regulation plays a crucial role in the expression of many genes in response to exogenous or endogenous signals in plants as well as other organisms. One of epigenetic mechanisms is modifications of histone, such as acetylation and deacetylation, are catalyzed by histone acetyltransferase (HAT) and histone deacetylase (HDAC), respectively. The Arabidopsis HDACs, HDA6, and HDA19, were reported to function in physiological processes, including embryo development, abiotic stress response, and flowering. In this study, we demonstrated that histone deacetylase inhibitors (HDIs) inhibit primary root elongation and lateral root emergence. In response to HDIs treatment, the PIN1 protein was almost abolished in the root tip. However, the PIN1 gene did not show decreased expression in the presence of HDIs, whereas IAA genes exhibited increases in transcript levels. In contrast, we observed a stable level of gene expression of stress markers (KIN1 and COR15A) and a cell division marker (CYCB1). Taken together, these results suggest that epigenetic regulation may control auxin-mediated root development through the 26S proteasome-mediated degradation of PIN1 protein.

  19. Extrusion of Debris from Primary Molar Root Canals following Instrumentation with Traditional and New File Systems.

    Science.gov (United States)

    Thakur, Bhagyashree; Pawar, Ajinkya M; Kfir, Anda; Neelakantan, Prasanna

    2017-11-01

    To assess the amount of debris extruded apically during instrumentation of distal canals of extracted primary molars by three instrument systems [ProTaper Universal (PTU), ProTaper NEXT (PTN), and self-adjusting file (SAF)] compared with conventional stainless steel hand K-files (HF, control). Primary mandibular molars (n = 120) with a single distal canal were selected and randomly divided into four groups (n = 30) for root canal instrumentation using group I, HF (to size 0.30/0.02 taper), group II, PTU (to size F3), group III, PTN (to size X3), and group IV, SAF. Debris extruded during instrumentation was collected in preweighed Eppendorf tubes, stored in an incubator at 70°C for 5 days and then weighed. Statistical analysis was performed by one-way analysis of variance (ANOVA), followed by Turkey's post hoc test (p = 0.05). All the groups resulted in extrusion of debris. There was statistically significant difference (p < 0.001) in the debris extrusion between the three groups: HF (0.00133 ± 0.00012), PTU (0.00109 ± 0.00005), PTN (0.00052 ± 0.00008), and SAF (0.00026 ± 0.00004). Instrumentation with SAF resulted in the least debris extrusion when used for shaping root canals of primary molar teeth. Debris extrusion in primary teeth poses an adverse effect on the stem cells and may also alter the permanent dental germ. Debris extrusion is rarely reported for primary teeth and it is important for the clinician to know which endodontic instrumentation leads to less extrusion of debris.

  20. Gamma ray irradiation to roots of tea-plants and induced mutant system

    International Nuclear Information System (INIS)

    Takeda, Yoshiyuki; Nekaku, Koji; Wada, Mitsumasa

    1990-01-01

    In order to utilize the useful mutation which is induced by irradiation for the breeding of tea-plants, the gamma-ray irradiation to the roots of tea-plants was carried out. The samples were the roots of tea-plants of four varieties dug up in February, 1984, and were adjusted to about 20 cm, then, put in the cold storage at 5degC for 9 months till the time of irradiation in November, 1984. However, a part of them was taken out in August, and planted in a field for 76 days to germinate, thereafter, used as the samples. The gamma-ray from a Co-60 source was irradiated in the radiation breeding laboratory of Agriculture Bioresources Research Institute at the total dose of 1, 2 and 3 kR and the dose rate of 500 R/h. The irradiated roots were planted as they are or in the state of being cut, and the rate of germination, the number of buds and the induced mutation were examined. Clear difference was not observed in the rate of germination and the number of buds between the irradiated samples and those without irradiation. The long roots were superior to the short roots regarding these items. The types of the induced mutation were mostly thin leaves, and also yellowing, mottling, fascination and so on occurred. The mutant system lacking trichomes on the back of new leaves is considered to be strong against tea anthracnose, and is valuable. (K.I.)

  1. Gamma ray irradiation to roots of tea-plants and induced mutant system

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Yoshiyuki; Nekaku, Koji; Wada, Mitsumasa (National Research Inst. of Vegetables, Ornamental Plants and Tea, Ano, Mie (Japan))

    1990-11-01

    In order to utilize the useful mutation which is induced by irradiation for the breeding of tea-plants, the gamma-ray irradiation to the roots of tea-plants was carried out. The samples were the roots of tea-plants of four varieties dug up in February, 1984, and were adjusted to about 20 cm, then, put in the cold storage at 5degC for 9 months till the time of irradiation in November, 1984. However, a part of them was taken out in August, and planted in a field for 76 days to germinate, thereafter, used as the samples. The gamma-ray from a Co-60 source was irradiated in the radiation breeding laboratory of Agriculture Bioresources Research Institute at the total dose of 1, 2 and 3 kR and the dose rate of 500 R/h. The irradiated roots were planted as they are or in the state of being cut, and the rate of germination, the number of buds and the induced mutation were examined. Clear difference was not observed in the rate of germination and the number of buds between the irradiated samples and those without irradiation. The long roots were superior to the short roots regarding these items. The types of the induced mutation were mostly thin leaves, and also yellowing, mottling, fascination and so on occurred. The mutant system lacking trichomes on the back of new leaves is considered to be strong against tea anthracnose, and is valuable. (K.I.).

  2. The root/rhizome system of seagrasses: an asset and a burden

    NARCIS (Netherlands)

    Hemminga, M.A.

    1998-01-01

    Large-scale declines in seagrass vegetation have been frequently observed in recent decades. Many of these declines can be traced to the reduction of light levels in the water column. In this paper, it is argued that the root/rhizome system offers a competitive advantage in nutrient-poor waters, but

  3. Root Systems Biology: Integrative Modeling across Scales, from Gene Regulatory Networks to the Rhizosphere1

    Science.gov (United States)

    Hill, Kristine; Porco, Silvana; Lobet, Guillaume; Zappala, Susan; Mooney, Sacha; Draye, Xavier; Bennett, Malcolm J.

    2013-01-01

    Genetic and genomic approaches in model organisms have advanced our understanding of root biology over the last decade. Recently, however, systems biology and modeling have emerged as important approaches, as our understanding of root regulatory pathways has become more complex and interpreting pathway outputs has become less intuitive. To relate root genotype to phenotype, we must move beyond the examination of interactions at the genetic network scale and employ multiscale modeling approaches to predict emergent properties at the tissue, organ, organism, and rhizosphere scales. Understanding the underlying biological mechanisms and the complex interplay between systems at these different scales requires an integrative approach. Here, we describe examples of such approaches and discuss the merits of developing models to span multiple scales, from network to population levels, and to address dynamic interactions between plants and their environment. PMID:24143806

  4. The microtubule associated protein END BINDING 1 represses root responses to mechanical cues.

    Science.gov (United States)

    Gleeson, Laura; Squires, Shannon; Bisgrove, Sherryl R

    2012-05-01

    The ability of roots to navigate around rocks and other debris as they grow through the soil requires a mechanism for detecting and responding to input from both touch and gravity sensing systems. The microtubule associated protein END BINDING 1b (EB1b) is involved in this process as mutants have defects responding to combinations of touch and gravity cues. This study investigates the role of EB1b in root responses to mechanical cues. We find that eb1b-1 mutant roots exhibit an increase over wild type in their response to touch and that the expression of EB1b genes in transgenic mutants restores the response to wild type levels, indicating that EB1b is an inhibitor of the response. Mutant roots are also hypersensitive to increased levels of mechanical stimulation, revealing the presence of another process that activates the response. These findings are supported by analyses of double mutants between eb1b-1 and seedlings carrying mutations in PHOSPHOGLUCOMUTASE (PGM), ALTERED RESPONSE TO GRAVITY1 (ARG1), or TOUCH3 (TCH3), genes that encode proteins involved in gravity sensing, signaling, or touch responses, respectively. A model is proposed in which root responses to mechanical cues are modulated by at least two competing regulatory processes, one that promotes touch-mediated growth and another, regulated by EB1b, which dampens root responses to touch and enhances gravitropism. © 2012. Published by Elsevier Ireland Ltd. All rights reserved.

  5. Public-domain software for root image analysis

    Directory of Open Access Journals (Sweden)

    Mirian Cristina Gomes Costa

    2014-10-01

    Full Text Available In the search for high efficiency in root studies, computational systems have been developed to analyze digital images. ImageJ and Safira are public-domain systems that may be used for image analysis of washed roots. However, differences in root properties measured using ImageJ and Safira are supposed. This study compared values of root length and surface area obtained with public-domain systems with values obtained by a reference method. Root samples were collected in a banana plantation in an area of a shallower Typic Carbonatic Haplic Cambisol (CXk, and an area of a deeper Typic Haplic Ta Eutrophic Cambisol (CXve, at six depths in five replications. Root images were digitized and the systems ImageJ and Safira used to determine root length and surface area. The line-intersect method modified by Tennant was used as reference; values of root length and surface area measured with the different systems were analyzed by Pearson's correlation coefficient and compared by the confidence interval and t-test. Both systems ImageJ and Safira had positive correlation coefficients with the reference method for root length and surface area data in CXk and CXve. The correlation coefficient ranged from 0.54 to 0.80, with lowest value observed for ImageJ in the measurement of surface area of roots sampled in CXve. The IC (95 % revealed that root length measurements with Safira did not differ from that with the reference method in CXk (-77.3 to 244.0 mm. Regarding surface area measurements, Safira did not differ from the reference method for samples collected in CXk (-530.6 to 565.8 mm² as well as in CXve (-4231 to 612.1 mm². However, measurements with ImageJ were different from those obtained by the reference method, underestimating length and surface area in samples collected in CXk and CXve. Both ImageJ and Safira allow an identification of increases or decreases in root length and surface area. However, Safira results for root length and surface area are

  6. Assessment of the root system of Brassica juncea (L.) czern. and Bidens pilosa L. exposed to lead polluted soils using rhizobox systems.

    Science.gov (United States)

    Graziani, Natalia Soledad; Salazar, María Julieta; Pignata, María Luisa; Rodriguez, Judith Hebelen

    2016-01-01

    The purpose of this study was to compare the behavior of the root system of one of the most frequently cited species in phytoremediation Indian mustard [Brassica juncea (L.) Czern.] and a representative perennial herb (Bidens pilosa L.) native of Argentina, for different concentrations of lead in soils through chemical and visualization techniques of the rhizosphere. Lead polluted soils from the vicinity of a lead recycling plant in the locality of Bouwer, were used in juxtaposed rhizobox systems planted with seedlings of B. juncea and B. pilosa with homogeneous and heterogeneous soil treatments. Root development, pH changes in the rhizosphere, dry weight biomass, lead content of root and aerial parts and potential extraction of lead by rhizosphere exudates were determined. In both species lead was mainly accumulated in roots. However, although B. juncea accumulated more lead than B. pilosa at elevated concentrations in soils, the latter achieved greater root and aerial development. No changes in the pH of the rhizosphere associated to lead were observed, despite different extractive potentials of lead in the exudates of the species analyzed. Our results indicated that Indian mustard did not behave as a hyperaccumulator in the conditions of the present study.

  7. Aplikasi Root Zone Cooling System Untuk Perbaikan Pembentukan Umbi Bawang Merah (Allium cepa var. aggregatum

    Directory of Open Access Journals (Sweden)

    Nurwahyuningsih

    2017-08-01

    Full Text Available Abstract The aim of this research can be formulated as follows: to analyze the effect of different root zone temperature to some extent the temperature is 10oC, 15oC, control and vernalization of plant growth and the formation of shallot bulbs by using aeroponic system. The experimental design used was a draft Plots Divided (Split Plot Design, which is arranged in a randomized block design with four replications. The main plot is a vernalization treatment (without vernalization and with vernalization. The subplots in the form of a nutrient solution temperature at 10oC, 15oC, and without cooling system as a control. The parameters measured were the number of leaves, the number of tillers, the number of bulbs, the weight of bulbs and the wet weight of root. There are no interaction between the annealing temperature by vernalization to the number of leaves, the bulb number, the weight of bulbs, and the weight of the roots. Cooling temperatures nutrient solution to improving root growth and bulb formation of shallot. Optimal root growth can improve nutrient uptaken by plants then can improve plant growth and bulb yield larger and heavier. Temperatures suitable for shallot cultivation in lowland tropical for producing tubers with quenching temperature is 10°C, non vernalization.

  8. Arabidopsis: an adequate model for dicot root systems

    Science.gov (United States)

    In the search for answers to pressing root developmental genetic issues, plant science has turned to a small genome dicot plant (Arabidopsis) to be used as a model to study and use to develop hypotheses for testing other species. Through out the published research only three classes of root are des...

  9. Histobacteriologic Conditions of the Apical Root Canal System and Periapical Tissues in Teeth Associated with Sinus Tracts.

    Science.gov (United States)

    Ricucci, Domenico; Loghin, Simona; Gonçalves, Lucio S; Rôças, Isabela N; Siqueira, José F

    2018-03-01

    This histobacteriologic study described the pattern of intraradicular and extraradicular infections in teeth with sinus tracts and chronic apical abscesses. The material comprised biopsy specimens from 24 (8 untreated and 16 treated) roots of teeth associated with apical periodontitis and a sinus tract. Specimens were obtained by periradicular surgery or extraction and were processed for histobacteriologic and histopathologic methods. Bacteria were found in the apical root canal system of all specimens, in the main root canal (22 teeth) and within ramifications (17 teeth). Four cases showed no extraradicular infection. Extraradicular bacteria occurred as a biofilm attached to the outer root surface in 17 teeth (5 untreated and 12 treated teeth), as actinomycotic colonies in 2 lesions, and as planktonic cells in 2 lesions. Extraradicular calculus formation (mineralized biofilm) was evident in 10 teeth. Teeth with chronic apical abscesses and sinus tracts showed a very complex infectious pattern in the apical root canal system and periapical lesion, with a predominance of biofilms. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  10. Microbial Growth and Carbon Use Efficiency in the Rhizosphere and Root-Free Soil

    Science.gov (United States)

    Blagodatskaya, Evgenia; Blagodatsky, Sergey; Anderson, Traute-Heidi; Kuzyakov, Yakov

    2014-01-01

    Plant-microbial interactions alter C and N balance in the rhizosphere and affect the microbial carbon use efficiency (CUE)–the fundamental characteristic of microbial metabolism. Estimation of CUE in microbial hotspots with high dynamics of activity and changes of microbial physiological state from dormancy to activity is a challenge in soil microbiology. We analyzed respiratory activity, microbial DNA content and CUE by manipulation the C and nutrients availability in the soil under Beta vulgaris. All measurements were done in root-free and rhizosphere soil under steady-state conditions and during microbial growth induced by addition of glucose. Microorganisms in the rhizosphere and root-free soil differed in their CUE dynamics due to varying time delays between respiration burst and DNA increase. Constant CUE in an exponentially-growing microbial community in rhizosphere demonstrated the balanced growth. In contrast, the CUE in the root-free soil increased more than three times at the end of exponential growth and was 1.5 times higher than in the rhizosphere. Plants alter the dynamics of microbial CUE by balancing the catabolic and anabolic processes, which were decoupled in the root-free soil. The effects of N and C availability on CUE in rhizosphere and root-free soil are discussed. PMID:24722409

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

    Directory of Open Access Journals (Sweden)

    Christopher Hepworth

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

  12. Iron- and ferritin-dependent reactive oxygen species distribution: impact on Arabidopsis root system architecture.

    Science.gov (United States)

    Reyt, Guilhem; Boudouf, Soukaina; Boucherez, Jossia; Gaymard, Frédéric; Briat, Jean-Francois

    2015-03-01

    Iron (Fe) homeostasis is integrated with the production of reactive oxygen species (ROS), and distribution at the root tip participates in the control of root growth. Excess Fe increases ferritin abundance, enabling the storage of Fe, which contributes to protection of plants against Fe-induced oxidative stress. AtFer1 and AtFer3 are the two ferritin genes expressed in the meristematic zone, pericycle and endodermis of the Arabidopsis thaliana root, and it is in these regions that we observe Fe stained dots. This staining disappears in the triple fer1-3-4 ferritin mutant. Fe excess decreases primary root length in the same way in wild-type and in fer1-3-4 mutant. In contrast, the Fe-mediated decrease of lateral root (LR) length and density is enhanced in fer1-3-4 plants due to a defect in LR emergence. We observe that this interaction between excess Fe, ferritin, and root system architecture (RSA) is in part mediated by the H2O2/O2·- balance between the root cell proliferation and differentiation zones regulated by the UPB1 transcription factor. Meristem size is also decreased in response to Fe excess in ferritin mutant plants, implicating cell cycle arrest mediated by the ROS-activated SMR5/SMR7 cyclin-dependent kinase inhibitors pathway in the interaction between Fe and RSA. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

  13. Soybean root growth and crop yield in reponse to liming at the beginning of a no-tillage system

    Directory of Open Access Journals (Sweden)

    Edson Campanhola Bortoluzzi

    2014-02-01

    Full Text Available Analyzing the soil near crop roots may reveal limitations to growth and yield even in a no-tillage system. The purpose of the present study was to relate the chemical and physical properties of soil under a no-tillage system to soybean root growth and plant yield after five years of use of different types of limestone and forms of application. A clayey Oxisol received application of dolomitic and calcitic limestones and their 1:1 combination in two forms: surface application, maintained on the soil surface; and incorporated, applied on the surface and incorporated mechanically. Soil physical properties (resistance to mechanical penetration, soil bulk density and soil aggregation, soil chemical properties (pH, exchangeable cations, H+Al, and cation exchange capacity and plant parameters (root growth system, soybean grain yield, and oat dry matter production were evaluated five years after setting up the experiment. Incorporation of lime neutralized exchangeable Al up to a depth of 20 cm without affecting the soil physical properties. The soybean root system reached depths of 40 cm or more with incorporated limestone, increasing grain yield an average of 31 % in relation to surface application, which limited the effect of lime up to a depth of 5 cm and root growth up to 20 cm. It was concluded that incorporation of limestone at the beginning of a no-tillage system ensures a favorable environment for root growth and soybean yield, while this intervention does not show long-term effects on soil physical properties under no-tillage. This suggests that there is resilience in the physical properties evaluated.

  14. Radiographic technical quality of root canal treatment performed by a new rotary single-file system.

    Science.gov (United States)

    Colombo, Marco; Bassi, Cristina; Beltrami, Riccardo; Vigorelli, Paolo; Spinelli, Antonio; Cavada, Andrea; Dagna, Alberto; Chiesa, Marco; Poggio, Claudio

    2017-01-01

    The aim of the present study was to evaluate radiographically the technical quality of root canal filling performed by postgraduate students with a new single-file Nickel-Titanium System (F6 Skytaper Komet) in clinical practice. Records of 74 patients who had received endodontic treatment by postgraduate students at the School of Dentistry, Faculty of Medicine, University of Pavia in the period between September 2015 and April 2016 were collected and examined: the final sample consisted 114 teeth and 204 root canals. The quality of endodontic treatment was evaluated by examining the length of the filling in relation to the radiographic apex, the density of the obturation according to the presence of voids and the taper of root canal filling. Chi-squared analysis was used to determine statistically significant differences between the technical quality of root fillings according to tooth's type, position and curvature. The results showed that 75,49%, 82,84% and 90,69% of root filled canals had adequate length, density and taper respectively. Overall, the technical quality of root canal fillings performed by postgraduates students was acceptable in 60,78% of the cases.

  15. Root inoculation with Pseudomonas putida KT2440 induces transcriptional and metabolic changes and systemic resistance in maize plants

    Directory of Open Access Journals (Sweden)

    Chantal ePlanchamp

    2015-01-01

    Full Text Available Pseudomonas putida KT2440 (KT2440 rhizobacteria colonize a wide range of plants. They have been extensively studied for their capacity to adhere to maize seeds, to tolerate toxic secondary metabolites produced by maize roots and to be attracted by maize roots. However, the response of maize plants to KT2440 colonization has not been investigated yet. Maize roots were inoculated with KT2440 and the local (roots and systemic (leaves early plant responses were investigated. The colonization behavior of KT2440 following application to maize seedlings was investigated and transcriptional analysis of stress- and defense-related genes as well as metabolite profiling of local and systemic maize tissues of KT2440-inoculated were performed. The local and systemic responses differed and more pronounced changes were observed in roots compared to leaves. Early in the interaction roots responded via jasmonic acid- and abscisic acid-dependent signaling. Interestingly, during later steps, the salicylic acid pathway was suppressed. Metabolite profiling revealed the importance of plant phospholipids in KT2440-maize interactions. An additional important maize secondary metabolite, a form of benzoxazinone, was also found to be differently abundant in roots three days after KT2440 inoculation. However, the transcriptional and metabolic changes observed in bacterized plants early during the interaction were minor and became even less pronounced with time, indicating an accommodation state of the plant to the presence of KT2440. Since the maize plants reacted to the presence of KT2440 in the rhizosphere, we also investigated the ability of these bacteria to trigger induced systemic resistance (ISR against the maize anthracnose fungus Colletotrichum graminicola. The observed resistance was expressed as strongly reduced leaf necrosis and fungal development in infected bacterized plants compared to non-bacterized controls, showing the potential of KT2440 to act as

  16. Influence of operator's experience on root canal shaping ability with a rotary nickel-titanium single-file reciprocating motion system.

    Science.gov (United States)

    Muñoz, Estefanía; Forner, Leopoldo; Llena, Carmen

    2014-04-01

    The aim of this study was to evaluate the influence of the operator's experience on the shaping of double-curvature simulated root canals with a nickel-titanium single-file reciprocating motion system. Sixty double-curvature root canals simulated in methacrylate blocks were prepared by 10 students without any experience in endodontics and by 10 professionals who had studied endodontics at the postgraduate level. The Reciproc-VDW system's R25 file was used in the root canal preparation. The blocks were photographed before and after the instrumentation, and the time of instrumentation was also evaluated. Changes in root canal dimensions were analyzed in 6 positions. Significant differences (P file reciprocating motion system Reciproc is not seen to be influenced by the operator's experience regarding the increase of the canal area. Previous training and the need to acquire experience are important in the use of this system, in spite of its apparent simplicity. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  17. Chrysanthemum cutting productivity and rooting ability are improved by grafting.

    Science.gov (United States)

    Zhang, Jing; Chen, Sumei; Liu, Ruixia; Jiang, Jiafu; Chen, Fadi; Fang, Weimin

    2013-01-01

    Chrysanthemum has been commercially propagated by rooting of cuttings, whereas the quality will decline over multiple collections from a single plant. Therefore, we compared the vigour, rooting ability, and some physiological parameters between cuttings harvested from nongrafted "Jinba" (non-grafted cuttings) with those collected from grafted "Jinba" plants onto Artemisia scoparia as a rootstock (grafted cuttings). The yield, length, node number, stem diameter, fresh weight, and dry weight of the grafted cuttings were superior to the non-grafted cuttings. Also grafted cuttings "Jinba" rooted 1 day earlier, but showing enhanced rooting quality including number, length, diameter, and dry weight of roots, where compared to the non-grafted. The physiological parameters that indicated contents of soluble protein, peroxidase activity, soluble sugar, and starch, ratios of soluble sugar/nitrogen ratio, and carbohydrate/nitrogen (C/N), as well as contents of indole-3-acetic acid (IAA) and abscisic acid (ABA), and IAA/ABA ratio were significantly increased in the grafted cuttings. This suggested their important parts in mediating rooting ability. Results from this study showed that grafting improved productivity and rooting ability related to an altered physiology, which provide a means to meet the increasing demand.

  18. Brassinosteroid signaling-dependent root responses to prolonged elevated ambient temperature.

    Science.gov (United States)

    Martins, Sara; Montiel-Jorda, Alvaro; Cayrel, Anne; Huguet, Stéphanie; Roux, Christine Paysant-Le; Ljung, Karin; Vert, Grégory

    2017-08-21

    Due to their sessile nature, plants have to cope with and adjust to their fluctuating environment. Temperature elevation stimulates the growth of Arabidopsis aerial parts. This process is mediated by increased biosynthesis of the growth-promoting hormone auxin. How plant roots respond to elevated ambient temperature is however still elusive. Here we present strong evidence that temperature elevation impinges on brassinosteroid hormone signaling to alter root growth. We show that elevated temperature leads to increased root elongation, independently of auxin or factors known to drive temperature-mediated shoot growth. We further demonstrate that brassinosteroid signaling regulates root responses to elevated ambient temperature. Increased growth temperature specifically impacts on the level of the brassinosteroid receptor BRI1 to downregulate brassinosteroid signaling and mediate root elongation. Our results establish that BRI1 integrates temperature and brassinosteroid signaling to regulate root growth upon long-term changes in environmental conditions associated with global warming.Moderate heat stimulates the growth of Arabidopsis shoots in an auxin-dependent manner. Here, Martins et al. show that elevated ambient temperature modifies root growth by reducing the BRI1 brassinosteroid-receptor protein level and downregulating brassinosteroid signaling.

  19. Phytotoxic cyanamide affects maize (Zea mays) root growth and root tip function: from structure to gene expression.

    Science.gov (United States)

    Soltys, Dorota; Rudzińska-Langwald, Anna; Kurek, Wojciech; Szajko, Katarzyna; Sliwinska, Elwira; Bogatek, Renata; Gniazdowska, Agnieszka

    2014-05-01

    Cyanamide (CA) is a phytotoxic compound produced by four Fabaceae species: hairy vetch, bird vetch, purple vetch and black locust. Its toxicity is due to complex activity that involves the modification of both cellular structures and physiological processes. To date, CA has been investigated mainly in dicot plants. The goal of this study was to investigate the effects of CA in the restriction of the root growth of maize (Zea mays), representing the monocot species. CA (3mM) reduced the number of border cells in the root tips of maize seedlings and degraded their protoplasts. However, CA did not induce any significant changes in the organelle structure of other root cells, apart from increased vacuolization. CA toxicity was also demonstrated by its effect on cell cycle activity, endoreduplication intensity, and modifications of cyclins CycA2, CycD2, and histone HisH3 gene expression. In contrast, the arrangement of microtubules was not altered by CA. Treatment of maize seedlings with CA did not completely arrest mitotic activity, although the frequency of dividing cells was reduced. Furthermore, prolonged CA treatment increased the proportion of endopolyploid cells in the root tip. Cytological malformations were accompanied by an induction of oxidative stress in root cells, which manifested as enhanced accumulation of H2O2. Exposure of maize seedlings to CA resulted in an increased concentration of auxin and stimulated ethylene emission. Taken together, these findings suggested that the inhibition of root growth by CA may be a consequence of stress-induced morphogenic responses. Copyright © 2014. Published by Elsevier GmbH.

  20. 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.

  1. Lateral root formation and the multiple roles of auxin

    NARCIS (Netherlands)

    Du, Yujuan; Scheres, Ben

    2018-01-01

    Root systems can display variable architectures that contribute to survival strategies of plants. The model plant Arabidopsis thaliana possesses a tap root system, in which the primary root and lateral roots (LRs) are major architectural determinants. The phytohormone auxin fulfils multiple roles

  2. Adsorption of heavy metal from aqueous solution by dehydrated root powder of long-root Eichhornia crassipes.

    Science.gov (United States)

    Li, Qiang; Chen, Bo; Lin, Peng; Zhou, Jiali; Zhan, Juhong; Shen, Qiuying; Pan, Xuejun

    2016-01-01

    The root powder of long-root Eichhornia crassipes, as a new kind of biodegradable adsorbent, has been tested for aqueous adsorption of Pb, Zn, Cu, and Cd. From FT-IR, we found that the absorption peaks of phosphorous compounds, carbonyl, and nitrogenous compounds displayed obvious changes before and after adsorption which illustrated that plant characteristics may play a role in binding with metals. Surface properties and morphology of the root powders have been characterized by means of SEM and BET. Energy spectrum analysis showed that the metals were adsorbed on root powders after adsorption. Then, optimum quantity of powder, pH values, and metal ion concentrations in single-system and multi-system were detected to discuss the characteristics and mechanisms of metal adsorption. Freundlich model and the second-order kinetics equation could well describe the adsorption of heavy metals in single-metal system. The adsorption of Pb, Zn, and Cd in the multi-metal system decreased with the concentration increased. At last, competitive adsorption of every two metals on root powder proved that Cu and Pb had suppressed the adsorption performance of Cd and Zn.

  3. Automatic non-destructive three-dimensional acoustic coring system for in situ detection of aquatic plant root under the water bottom

    Directory of Open Access Journals (Sweden)

    Katsunori Mizuno

    2016-05-01

    Full Text Available Digging is necessary to detect plant roots under the water bottom. However, such detection is affected by the transparency of water and the working skills of divers, usually requires considerable time for high-resolution sampling, and always damages the survey site. We developed a new automatic non-destructive acoustic measurement system that visualizes the space under the water bottom, and tested the system in the in situ detection of natural plant roots. The system mainly comprises a two-dimensional waterproof stage controlling unit and acoustic measurement unit. The stage unit was electrically controlled through a notebook personal computer, and the space under the water bottom was scanned in a two-dimensional plane with the stage unit moving in steps of 0.01 m (±0.0001 m. We confirmed a natural plant root with diameter of 0.025–0.030 m in the reconstructed three-dimensional acoustic image. The plant root was at a depth of about 0.54 m and the propagation speed of the wave between the bottom surface and plant root was estimated to be 1574 m/s. This measurement system for plant root detection will be useful for the non-destructive assessment of the status of the space under the water bottom.

  4. Dynamics of plant nutrient uptake as affected by biopore-associated root growth in arable subsoil

    DEFF Research Database (Denmark)

    Han, Eusun; Kautz, Timo; Huang, Ning

    2017-01-01

    %) precrops, respectively. On average root diameter and root dry mass of following crops were greater by 11 and 15 % after chicory than tall fescue. At anthesis chicory-barley treatment accumulated 10 % more K in comparison to tall fescue-barley treatment. P uptake of canola was greater (7 %) after tall...... fescue compared with chicory at the stage of fruit development. Conclusions: Our results suggest that the subsoil heterogenization by altered soil biopores hold relevance for plant root growth and overall crop performance. However, the effects depended on biopore size classes, root characteristics...

  5. Evaluation of the morphological alteration of the root surface radiated with a diode laser; Avaliacao da alteracao morfologica da superficie cimentaria irradiada com laser de diodo

    Energy Technology Data Exchange (ETDEWEB)

    Gulin, Mauricio

    2003-07-01

    The diode laser has been studied for periodontal therapy, as much for removal of calculus as for microbial reduction of periodontal pockets, as well as the visible analgesic effects and biomodulation capacity. For this reason the purpose of this study was to evaluate the morphological alteration of the root surface after radiation with the diode laser, 808 nm through analysis by scanning electron microscopy (SEM). Besides this, to verify the temperature variations caused during the radiation, a thermometer put into the dentinal wall of the root canal was used. In all, 18 teeth were used, 15 of which for the SEM study, and the other 3 were used to temperature variation analysis. The 25 samples were scraped on the root surface and planed with manual instruments. The other 5 were not subjected to any type of treatment. This, 6 groups of 5 samples each were formed. Control Group C whose samples had not received any treatment; Control Group C 1 was only scraped and polished conventionally with Hu-Friedy Gracey curettes 5 and 6; the other samples groups L1, L2, L3, L4 were radiated by diode laser using parameters of power 1,0 W; 1,2 W; 1,4 W; and 1,6 W respectively, 2 times for 10 seconds with 20 seconds intervals between each radiation in continuous mode. The results with relation to the increase of temperature in the interior of the root canal demonstrated that there was an increase of more than 5 degree Celsius. The results of the scanning electron microscope analysis of Control Group C demonstrated great irregularity and ridges on the root surface, with the presence of a dentine layer. Control Group C1 presented a similar aspect to Group L 1's, smoother and more homogeneous surface. Groups L2, L3, and L4 presented scratches alternating with smoother areas showing that fiber contacted the surface of the sample. The results reconfirmed the necessity of further studies using diode laser, with a beam of light emitted in an interrupted mode to improve the control of the

  6. Evaluation of the morphological alteration of the root surface radiated with a diode laser; Avaliacao da alteracao morfologica da superficie cimentaria irradiada com laser de diodo

    Energy Technology Data Exchange (ETDEWEB)

    Gulin, Mauricio

    2003-07-01

    The diode laser has been studied for periodontal therapy, as much for removal of calculus as for microbial reduction of periodontal pockets, as well as the visible analgesic effects and biomodulation capacity. For this reason the purpose of this study was to evaluate the morphological alteration of the root surface after radiation with the diode laser, 808 nm through analysis by scanning electron microscopy (SEM). Besides this, to verify the temperature variations caused during the radiation, a thermometer put into the dentinal wall of the root canal was used. In all, 18 teeth were used, 15 of which for the SEM study, and the other 3 were used to temperature variation analysis. The 25 samples were scraped on the root surface and planed with manual instruments. The other 5 were not subjected to any type of treatment. This, 6 groups of 5 samples each were formed. Control Group C whose samples had not received any treatment; Control Group C 1 was only scraped and polished conventionally with Hu-Friedy Gracey curettes 5 and 6; the other samples groups L1, L2, L3, L4 were radiated by diode laser using parameters of power 1,0 W; 1,2 W; 1,4 W; and 1,6 W respectively, 2 times for 10 seconds with 20 seconds intervals between each radiation in continuous mode. The results with relation to the increase of temperature in the interior of the root canal demonstrated that there was an increase of more than 5 degree Celsius. The results of the scanning electron microscope analysis of Control Group C demonstrated great irregularity and ridges on the root surface, with the presence of a dentine layer. Control Group C1 presented a similar aspect to Group L 1's, smoother and more homogeneous surface. Groups L2, L3, and L4 presented scratches alternating with smoother areas showing that fiber contacted the surface of the sample. The results reconfirmed the necessity of further studies using diode laser, with a beam of light emitted in an interrupted mode to improve the control of

  7. Living roots effect on 14C-labelled root litter decomposition

    International Nuclear Information System (INIS)

    Billes, G.; Bottner, P.

    1981-01-01

    Wheat was 14 C-labelled by cultivation on soil in pots, from seedling to maturity, in a chamber with constant CO 2 and 14 CO 2 levels. The 14 C-distribution was constant amongst the aerial parts, the roots and the soil in the whole pots. After cutting the plant tops, the pots were dried without disturbing the soil and root system. The pots were then incubated under controlled humidity and temperature conditions for 62 days. In the same time a second wheat cultivation was grown on one half of the pots in normal atmosphere without plant cultivation. The purpose of the work is to study the effect of living roots on decomposition of the former 14 C labelled roots litter. The CO 2 and the 14 CO 2 released from the soil were continuously measured. On incubation days 0, 18, 33 and 62, the remaining litter was separated from soil, and the organic matter was fractionated by repeated hydrolysis and NaOH extraction. Root litter disappeared faster when living roots were present than in bare soil. The accumulation and mineralization rates of humified components in soil followed two stages. While the roots of second wheat cultivation grew actively (until earing), the strong acid hydrolysable components accumulated in larger amount than in the case of bare soil. After earing, while roots activity was depressed, these components were partly mineralized and the 14 CO 2 release was then higher with plants than with bare soil. The humification and mineralization rate were related with living plant phenology stages. (orig.)

  8. Genetic transformation of rare Verbascum eriophorum Godr. plants and metabolic alterations revealed by NMR-based metabolomics.

    Science.gov (United States)

    Marchev, Andrey; Yordanova, Zhenya; Alipieva, Kalina; Zahmanov, Georgi; Rusinova-Videva, Snezhana; Kapchina-Toteva, Veneta; Simova, Svetlana; Popova, Milena; Georgiev, Milen I

    2016-09-01

    To develop a protocol to transform Verbascum eriophorum and to study the metabolic differences between mother plants and hairy root culture by applying NMR and processing the datasets with chemometric tools. Verbascum eriophorum is a rare species with restricted distribution, which is poorly studied. Agrobacterium rhizogenes-mediated genetic transformation of V. eriophorum and hairy root culture induction are reported for the first time. To determine metabolic alterations, V. eriophorum mother plants and relevant hairy root culture were subjected to comprehensive metabolomic analyses, using NMR (1D and 2D). Metabolomics data, processed using chemometric tools (and principal component analysis in particular) allowed exploration of V. eriophorum metabolome and have enabled identification of verbascoside (by means of 2D-TOCSY NMR) as the most abundant compound in hairy root culture. Metabolomics data contribute to the elucidation of metabolic alterations after T-DNA transfer to the host V. eriophorum genome and the development of hairy root culture for sustainable bioproduction of high value verbascoside.

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Günter eNeumann

    2014-01-01

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

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

    Science.gov (United States)

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

    2014-01-01

    Development and activity of plant roots exhibit high adaptive variability. Although it is well-documented, that physicochemical soil properties can strongly influence root morphology and root exudation, particularly under field conditions, a comparative assessment is complicated by the impact of additional factors, such as climate and cropping history. To overcome these limitations, in this study, field soils originating from an unique experimental plot system with three different soil types, which were stored at the same field site for 10 years and exposed to the same agricultural management practice, were used for an investigation on effects of soil type on root development and root exudation. Lettuce (Lactuca sativa L. cv. Tizian) was grown as a model plant under controlled environmental conditions in a minirhizotrone system equipped with root observation windows (rhizoboxes). Root exudates were collected by placing sorption filters onto the root surface followed by subsequent extraction and GC-MS profiling of the trapped compounds. Surprisingly, even in absence of external stress factors with known impact on root exudation, such as pH extremes, water and nutrient limitations/toxicities or soil structure effects (use of sieved soils), root growth characteristics (root length, fine root development) as well as profiles of root exudates were strongly influenced by the soil type used for plant cultivation. The results coincided well with differences in rhizosphere bacterial communities, detected in field-grown lettuce plants cultivated on the same soils (Schreiter et al., this issue). The findings suggest that the observed differences may be the result of plant interactions with the soil-specific microbiomes. PMID:24478764

  12. Parallelization and implementation of approximate root isolation for nonlinear system by Monte Carlo

    Science.gov (United States)

    Khosravi, Ebrahim

    1998-12-01

    This dissertation solves a fundamental problem of isolating the real roots of nonlinear systems of equations by Monte-Carlo that were published by Bush Jones. This algorithm requires only function values and can be applied readily to complicated systems of transcendental functions. The implementation of this sequential algorithm provides scientists with the means to utilize function analysis in mathematics or other fields of science. The algorithm, however, is so computationally intensive that the system is limited to a very small set of variables, and this will make it unfeasible for large systems of equations. Also a computational technique was needed for investigating a metrology of preventing the algorithm structure from converging to the same root along different paths of computation. The research provides techniques for improving the efficiency and correctness of the algorithm. The sequential algorithm for this technique was corrected and a parallel algorithm is presented. This parallel method has been formally analyzed and is compared with other known methods of root isolation. The effectiveness, efficiency, enhanced overall performance of the parallel processing of the program in comparison to sequential processing is discussed. The message passing model was used for this parallel processing, and it is presented and implemented on Intel/860 MIMD architecture. The parallel processing proposed in this research has been implemented in an ongoing high energy physics experiment: this algorithm has been used to track neutrinoes in a super K detector. This experiment is located in Japan, and data can be processed on-line or off-line locally or remotely.

  13. Physical root-soil interactions

    Science.gov (United States)

    Kolb, Evelyne; Legué, Valérie; Bogeat-Triboulot, Marie-Béatrice

    2017-12-01

    Plant root system development is highly modulated by the physical properties of the soil and especially by its mechanical resistance to penetration. The interplay between the mechanical stresses exerted by the soil and root growth is of particular interest for many communities, in agronomy and soil science as well as in biomechanics and plant morphogenesis. In contrast to aerial organs, roots apices must exert a growth pressure to penetrate strong soils and reorient their growth trajectory to cope with obstacles like stones or hardpans or to follow the tortuous paths of the soil porosity. In this review, we present the main macroscopic investigations of soil-root physical interactions in the field and combine them with simple mechanistic modeling derived from model experiments at the scale of the individual root apex.

  14. Rooting depth varies differentially in trees and grasses as a function of mean annual rainfall in an African savanna.

    Science.gov (United States)

    Holdo, Ricardo M; Nippert, Jesse B; Mack, Michelle C

    2018-01-01

    A significant fraction of the terrestrial biosphere comprises biomes containing tree-grass mixtures. Forecasting vegetation dynamics in these environments requires a thorough understanding of how trees and grasses use and compete for key belowground resources. There is disagreement about the extent to which tree-grass vertical root separation occurs in these ecosystems, how this overlap varies across large-scale environmental gradients, and what these rooting differences imply for water resource availability and tree-grass competition and coexistence. To assess the extent of tree-grass rooting overlap and how tree and grass rooting patterns vary across resource gradients, we examined landscape-level patterns of tree and grass functional rooting depth along a mean annual precipitation (MAP) gradient extending from ~ 450 to ~ 750 mm year -1 in Kruger National Park, South Africa. We used stable isotopes from soil and stem water to make inferences about relative differences in rooting depth between these two functional groups. We found clear differences in rooting depth between grasses and trees across the MAP gradient, with grasses generally exhibiting shallower rooting profiles than trees. We also found that trees tended to become more shallow-rooted as a function of MAP, to the point that trees and grasses largely overlapped in terms of rooting depth at the wettest sites. Our results reconcile previously conflicting evidence for rooting overlap in this system, and have important implications for understanding tree-grass dynamics under altered precipitation scenarios.

  15. 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.

  16. UV-B Radiation Induces Root Bending Through the Flavonoid-Mediated Auxin Pathway in Arabidopsis.

    Science.gov (United States)

    Wan, Jinpeng; Zhang, Ping; Wang, Ruling; Sun, Liangliang; Wang, Wenying; Zhou, Huakun; Xu, Jin

    2018-01-01

    Ultraviolet (UV)-B radiation-induced root bending has been reported; however, the underlying mechanisms largely remain unclear. Here, we investigate whether and how auxin and flavonoids are involved in UV-B radiation-induced root bending in Arabidopsis using physiological, pharmacological, and genetic approaches. UV-B radiation modulated the direction of root growth by decreasing IAA biosynthesis and affecting auxin distribution in the root tips, where reduced auxin accumulation and asymmetric auxin distribution were observed. UV-B radiation increased the distribution of auxin on the nonradiated side of the root tips, promoting growth and causing root bending. Further analysis indicated that UV-B induced an asymmetric accumulation of flavonoids; this pathway is involved in modulating the accumulation and asymmetric distribution of auxin in root tips and the subsequent redirection of root growth by altering the distribution of auxin carriers in response to UV-B radiation. Taken together, our results indicate that UV-B radiation-induced root bending occurred through a flavonoid-mediated phototropic response to UV-B radiation.

  17. Sistema radicular do fórmio, sisal e bambu imperial Root systems of new zealand flax, sisal, and imperial bamboo

    Directory of Open Access Journals (Sweden)

    Júlio César Medina

    1963-01-01

    Full Text Available Os autores apresentam e discutem os resultados de estudos preliminares sôbre o sistema radicular do fórmio (Phormium tenax Forster, sisal (Agave sisalana Perrine e bambu .imperial (Bambusa vulgaris Schrad. var. vittata A. ,& C, Riv.. Concluem, que o sistema radicular do fórmio é relativamente raso, o do sisal bastante superficial é o do bambu imperial se limitada às primeiras carnadas do solo.Results of preliminary studies on root-systems of New Zealand flax (Phormium tenax Forster, sisal (Agave sisalana Perrine, and imperial bamboo (Bambusa vulgaris Schrad. var. vittata A. & C. Riv. plants by the method of soil block, are apresented and discussed by the authors. According to local soil conditions, it is concluded that the root-system of New Zealand flax is relatively superficial, with the main concentration of roots in the 12 in. soil top layer. In sisal, the root-systems of the three plants investigated were found to occur in the soil surface layer, with more of 90% of the roots in the top 6 in. Finally, in the imperial bamboo clump atudied, the main concentration of roots was found in the layer 6-12 in. deep.

  18. A novel interaction between plant-beneficial rhizobacteria and roots: colonization induces corn resistance against the root herbivore Diabrotica speciosa.

    Science.gov (United States)

    Santos, Franciele; Peñaflor, Maria Fernanda G V; Paré, Paul W; Sanches, Patrícia A; Kamiya, Aline C; Tonelli, Mateus; Nardi, Cristiane; Bento, José Mauricio S

    2014-01-01

    A number of soil-borne microorganisms, such as mycorrhizal fungi and rhizobacteria, establish mutualistic interactions with plants, which can indirectly affect other organisms. Knowledge of the plant-mediated effects of mutualistic microorganisms is limited to aboveground insects, whereas there is little understanding of what role beneficial soil bacteria may play in plant defense against root herbivory. Here, we establish that colonization by the beneficial rhizobacterium Azospirillum brasilense affects the host selection and performance of the insect Diabrotica speciosa. Root larvae preferentially orient toward the roots of non-inoculated plants versus inoculated roots and gain less weight when feeding on inoculated plants. As inoculation by A. brasilense induces higher emissions of (E)-β-caryophyllene compared with non-inoculated plants, it is plausible that the non-preference of D. speciosa for inoculated plants is related to this sesquiterpene, which is well known to mediate belowground insect-plant interactions. To the best of our knowledge, this is the first study showing that a beneficial rhizobacterium inoculant indirectly alters belowground plant-insect interactions. The role of A. brasilense as part of an integrative pest management (IPM) program for the protection of corn against the South American corn rootworm, D. speciosa, is considered.

  19. Arbuscular mycorrhizal assemblages in native plant roots change in the presence of invasive exotic grasses

    Science.gov (United States)

    Hawkes, C.V.; Belnap, J.; D'Antonio, C.; Firestone, M.K.

    2006-01-01

    Plant invasions have the potential to significantly alter soil microbial communities, given their often considerable aboveground effects. We examined how plant invasions altered the arbuscular mycorrhizal fungi of native plant roots in a grassland site in California and one in Utah. In the California site, we used experimentally created plant communities composed of exotic (Avena barbata, Bromus hordeaceus) and native (Nassella pulchra, Lupinus bicolor) monocultures and mixtures. In the Utah semi-arid grassland, we took advantage of invasion by Bromus tectorum into long-term plots dominated by either of two native grasses, Hilaria jamesii or Stipa hymenoides. Arbuscular mycorrhizal fungi colonizing roots were characterized with PCR amplification of the ITS region, cloning, and sequencing. We saw a significant effect of the presence of exotic grasses on the diversity of mycorrhizal fungi colonizing native plant roots. In the three native grasses, richness of mycorrhizal fungi decreased; in the native forb at the California site, the number of fungal RFLP patterns increased in the presence of exotics. The exotic grasses also caused the composition of the mycorrhizal community in native roots to shift dramatically both in California, with turnover of Glomus spp., and Utah, with replacement of Glomus spp. by apparently non-mycorrhizal fungi. Invading plants may be able to influence the network of mycorrhizal fungi in soil that is available to natives through either earlier root activity or differential carbon provision compared to natives. Alteration of the soil microbial community by plant invasion can provide a mechanism for both successful invasion and the resulting effects of invaders on the ecosystem. ?? Springer 2006.

  20. Method and Apparatus Providing Deception and/or Altered Operation in an Information System Operating System

    Science.gov (United States)

    Cohen, Fred; Rogers, Deanna T.; Neagoe, Vicentiu

    2008-10-14

    A method and/or system and/or apparatus providing deception and/or execution alteration in an information system. In specific embodiments, deceptions and/or protections are provided by intercepting and/or modifying operation of one or more system calls of an operating system.

  1. Endodontic treatment of mandibular molar with root dilaceration using Reciproc single-file system.

    Science.gov (United States)

    Meireles, Daniely Amorin; Bastos, Mariana Mena Barreto; Marques, André Augusto Franco; Garcia, Lucas da Fonseca Roberti; Sponchiado, Emílio Carlos

    2013-08-01

    Biomechanical preparation of root canals with accentuated curvature is challenging. New rotatory systems, such as Reciproc, require a shorter period of time to prepare curved canals, and became a viable alternative for endodontic treatment of teeth with root dilaceration. Thus, this study aimed to report a clinical case of endodontic therapy of root with accentuated dilaceration using Reciproc single-file system. Mandibular right second molar was diagnosed as asymptomatic irreversible pulpitis. Pulp chamber access was performed, and glide path was created with #10 K-file (Dentsply Maillefer) and PathFile #13, #16 and #19 (Dentsply Maillefer) up to the temporary working length. The working length measured corresponded to 20 mm in the mesio-buccal and mesio-lingual canals, and 22 mm in the distal canal. The R25 file (VDW GmbH) was used in all the canals for instrumentation and final preparation, followed by filling with Reciproc gutta-percha cones (VDW GmbH) and AH Plus sealer (Dentsply Maillefer), using thermal compaction technique. The case has been receiving follow-up for 6 mon and no painful symptomatology or periapical lesions have been found. Despite the difficulties, the treatment could be performed in a shorter period of time than the conventional methods.

  2. Endodontic treatment of mandibular molar with root dilaceration using Reciproc single-file system

    Directory of Open Access Journals (Sweden)

    Daniely Amorin Meireles

    2013-08-01

    Full Text Available Biomechanical preparation of root canals with accentuated curvature is challenging. New rotatory systems, such as Reciproc, require a shorter period of time to prepare curved canals, and became a viable alternative for endodontic treatment of teeth with root dilaceration. Thus, this study aimed to report a clinical case of endodontic therapy of root with accentuated dilaceration using Reciproc single-file system. Mandibular right second molar was diagnosed as asymptomatic irreversible pulpitis. Pulp chamber access was performed, and glide path was created with #10 K-file (Dentsply Maillefer and PathFile #13, #16 and #19 (Dentsply Maillefer up to the temporary working length. The working length measured corresponded to 20 mm in the mesio-buccal and mesio-lingual canals, and 22 mm in the distal canal. The R25 file (VDW GmbH was used in all the canals for instrumentation and final preparation, followed by filling with Reciproc gutta-percha cones (VDW GmbH and AH Plus sealer (Dentsply Maillefer, using thermal compaction technique. The case has been receiving follow-up for 6 mon and no painful symptomatology or periapical lesions have been found. Despite the difficulties, the treatment could be performed in a shorter period of time than the conventional methods.

  3. [Root canal treatment of mandibular first premolar with 4 root canals: a case report].

    Science.gov (United States)

    Liu, Xin-yang; Zhan, Fu-Liang

    2015-10-01

    The mandibular first premolar can be considered one of the most challenging teeth to treat, due to the complexity of its root canal morphology and increased incidence of multiple canals. A case of endodontic treatment of a mandibular first premolar exhibiting a total of 4 distinct root canals and 4 apical foramina was described. Anatomic variation of root canal morphology should be considered in endodontic treatment to ensure a favorable healing outcome, and its identification could be enhanced by careful examination using a dental operating microscope. Obturation of root canals using a warm vertical compaction technique with a highly-radiopaque root canal sealer, such as AH Plus, after careful ultrasonic activated irrigation might allow the flow of sealer into the narrowed but unprepared part of the canal, thereby facilitating optimum chemo-mechanical debridement of the root canal system.

  4. Quantifying the contribution of the root system of alpine vegetation in the soil aggregate stability of moraine

    Directory of Open Access Journals (Sweden)

    Csilla Hudek

    2017-03-01

    Full Text Available One fifth of the world's population is living in mountains or in their surrounding areas. This anthropogenic pressure continues to grow with the increasing number of settlements, especially in areas connected to touristic activities, such as the Italian Alps. The process of soil formation on high mountains is particularly slow and these soils are particularly vulnerable to soil degradation. In alpine regions, extreme meteorological events are increasingly frequent due to climate change, speeding up the process of soil degradation and increasing the number of severe erosion processes, shallow landslides and debris flows. Vegetation cover plays a crucial role in the stabilization of mountain soils thereby reducing the risk of natural hazards effecting downslope areas. Soil aggregate stability is one of the main soil properties that can be linked to soil loss processes. Soils developed on moraines in recently deglaciated areas typically have low levels of soil aggregation, and a limited or discontinuous vegetation cover making them more susceptible to degradation. However, soil structure can be influenced by the root system of the vegetation. Roots are actively involved in the formation of water-stable soil aggregation, increasing the stability of the soil and its nutrient content. In the present study, we aim to quantify the effect of the root system of alpine vegetation on the soil aggregate stability of the forefield of the Lys glacier, in the Aosta Valley (NW-Italy. This proglacial area provides the opportunity to study how the root system of ten pioneer alpine species from different successional stages can contribute to soil development and soil stabilization. To quantify the aggregate stability of root permeated soils, a modified wet sieving method was employed. The root length per soil volume of the different species was also determined and later correlated with the aggregate stability results. The results showed that soil aggregate

  5. Fine-tuning by strigolactones of root response to low phosphate.

    Science.gov (United States)

    Kapulnik, Yoram; Koltai, Hinanit

    2016-03-01

    Strigolactones are plant hormones that regulate the development of different plant parts. In the shoot, they regulate axillary bud outgrowth and in the root, root architecture and root-hair length and density. Strigolactones are also involved with communication in the rhizosphere, including enhancement of hyphal branching of arbuscular mycorrhizal fungi. Here we present the role and activity of strigolactones under conditions of phosphate deprivation. Under these conditions, their levels of biosynthesis and exudation increase, leading to changes in shoot and root development. At least for the latter, these changes are likely to be associated with alterations in auxin transport and sensitivity. On the other hand, strigolactones may positively affect plant-mycorrhiza interactions and thereby promote phosphate acquisition by the plant. Strigolactones may be a way for plants to fine-tune their growth pattern under phosphate deprivation. © 2015 Institute of Botany, Chinese Academy of Sciences.

  6. Root tips moving through soil

    Science.gov (United States)

    Curlango-Rivera, Gilberto

    2011-01-01

    Root elongation occurs by the generation of new cells from meristematic tissue within the apical 1–2 mm region of root tips. Therefore penetration of the soil environment is carried out by newly synthesized plant tissue, whose cells are inherently vulnerable to invasion by pathogens. This conundrum, on its face, would seem to reflect an intolerable risk to the successful establishment of root systems needed for plant life. Yet root tip regions housing the meristematic tissues repeatedly have been found to be free of microbial infection and colonization. Even when spore germination, chemotaxis, and/or growth of pathogens are stimulated by signals from the root tip, the underlying root tissue can escape invasion. Recent insights into the functions of root border cells, and the regulation of their production by transient exposure to external signals, may shed light on long-standing observations. PMID:21455030

  7. Measurements of water uptake of maize roots: the key function of lateral roots

    Science.gov (United States)

    Ahmed, M. A.; Zarebanadkouki, M.; Kroener, E.; Kaestner, A.; Carminati, A.

    2014-12-01

    Maize (Zea mays L.) is one of the most important crop worldwide. Despite its importance, there is limited information on the function of different root segments and root types of maize in extracting water from soils. Therefore, the aim of this study was to investigate locations of root water uptake in maize. We used neutron radiography to: 1) image the spatial distribution of maize roots in soil and 2) trace the transport of injected deuterated water (D2O) in soil and roots. Maizes were grown in aluminum containers (40×38×1 cm) filled with a sandy soil. When the plants were 16 days old, we injected D2O into selected soil regions containing primary, seminal and lateral roots. The experiments were performed during the day (transpiring plants) and night (not transpiring plants). The transport of D2O into roots was simulated using a new convection-diffusion numerical model of D2O transport into roots. By fitting the observed D2O transport we quantified the diffusional permeability and the water uptake of the different root segments. The maize root architecture consisted of a primary root, 4-5 seminal roots and many lateral roots connected to the primary and seminal roots. Laterals emerged from the proximal 15 cm of the primary and seminal roots. Water uptake occurred primarily in lateral roots. Lateral roots had the highest diffusional permeability (9.4×10-7), which was around six times higher that the diffusional permeability of the old seminal segments (1.4×10-7), and two times higher than the diffusional permeability of the young seminal segments (4.7×10-7). The radial flow of D2O into the lateral (6.7×10-5 ) was much higher than in the young seminal roots (1.1×10-12). The radial flow of D2O into the old seminal was negligible. We concluded that the function of the primary and seminal roots was to collect water from the lateral roots and transport it to the shoot. A maize root system with lateral roots branching from deep primary and seminal roots would be

  8. Adventitious rooting declines with the vegetative to reproductive switch and involves a changed auxin homeostasis.

    Science.gov (United States)

    Rasmussen, Amanda; Hosseini, Seyed Abdollah; Hajirezaei, Mohammed-Reza; Druege, Uwe; Geelen, Danny

    2015-03-01

    Adventitious rooting, whereby roots form from non-root tissues, is critical to the forestry and horticultural industries that depend on propagating plants from cuttings. A major problem is that age of the tissue affects the ability of the cutting to form adventitious roots. Here, a model system has been developed using Pisum sativum to differentiate between different interpretations of ageing. It is shown that the decline in adventitious rooting is linked to the ontogenetic switch from vegetative to floral and is mainly attributed to the cutting base. Using rms mutants it is demonstrated that the decline is not a result of increased strigolactones inhibiting adventitious root formation. Monitoring endogenous levels of a range of other hormones including a range of cytokinins in the rooting zone revealed that a peak in jasmonic acid is delayed in cuttings from floral plants. Additionally, there is an early peak in indole-3-acetic acid levels 6h post excision in cuttings from vegetative plants, which is absent in cuttings from floral plants. These results were confirmed using DR5:GUS expression. Exogenous supplementation of young cuttings with either jasmonic acid or indole-3-acetic acid promoted adventitious rooting, but neither of these hormones was able to promote adventitious rooting in mature cuttings. DR5:GUS expression was observed to increase in juvenile cuttings with increasing auxin treatment but not in the mature cuttings. Therefore, it seems the vegetative to floral ontogenetic switch involves an alteration in the tissue's auxin homeostasis that significantly reduces the indole-3-acetic acid pool and ultimately results in a decline in adventitious root formation. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  9. Immune system alterations in amyotrophic lateral sclerosis

    DEFF Research Database (Denmark)

    Hovden, H; Frederiksen, J L; Pedersen, S W

    2013-01-01

    Amyotrophic lateral sclerosis is a disease of which the underlying cause and pathogenesis are unknown. Cumulatative data clearly indicates an active participation by the immune system in the disease. An increasingly recognized theory suggests a non-cell autonomous mechanism, meaning that multiple...... cells working together are necessary for the pathogenesis of the disease. Observed immune system alterations could indicate an active participation in this mechanism. Damaged motor neurons are able to activate microglia, astrocytes and the complement system, which further can influence each other...... and contribute to neurodegeneration. Infiltrating peripheral immune cells appears to correlate with disease progression, but their significance and composition is unclear. The deleterious effects of this collaborating system of cells appear to outweigh the protective aspects, and revealing this interplay might...

  10. Fusarium oxysporum mediates systems metabolic reprogramming of chickpea roots as revealed by a combination of proteomics and metabolomics.

    Science.gov (United States)

    Kumar, Yashwant; Zhang, Limin; Panigrahi, Priyabrata; Dholakia, Bhushan B; Dewangan, Veena; Chavan, Sachin G; Kunjir, Shrikant M; Wu, Xiangyu; Li, Ning; Rajmohanan, Pattuparambil R; Kadoo, Narendra Y; Giri, Ashok P; Tang, Huiru; Gupta, Vidya S

    2016-07-01

    Molecular changes elicited by plants in response to fungal attack and how this affects plant-pathogen interaction, including susceptibility or resistance, remain elusive. We studied the dynamics in root metabolism during compatible and incompatible interactions between chickpea and Fusarium oxysporum f. sp. ciceri (Foc), using quantitative label-free proteomics and NMR-based metabolomics. Results demonstrated differential expression of proteins and metabolites upon Foc inoculations in the resistant plants compared with the susceptible ones. Additionally, expression analysis of candidate genes supported the proteomic and metabolic variations in the chickpea roots upon Foc inoculation. In particular, we found that the resistant plants revealed significant increase in the carbon and nitrogen metabolism; generation of reactive oxygen species (ROS), lignification and phytoalexins. The levels of some of the pathogenesis-related proteins were significantly higher upon Foc inoculation in the resistant plant. Interestingly, results also exhibited the crucial role of altered Yang cycle, which contributed in different methylation reactions and unfolded protein response in the chickpea roots against Foc. Overall, the observed modulations in the metabolic flux as outcome of several orchestrated molecular events are determinant of plant's role in chickpea-Foc interactions. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  11. Evaluation of interference of calcium hydroxide-based intracanal medication in filling root canal systems.

    Science.gov (United States)

    Vilela, Deyla Duarte; Neto, Manoel Matos; Villela, Alexandre Mascarenhas; Pithon, Matheus Melo

    2011-09-01

    To evaluate the interference of the intracanal medication Calen® (SSWhite, Sao Paulo, Brazil) on the filling of simulated lateral canals. Twenty human anterior teeth were used. Before the endodontic filling procedures the access of cavity was made, and after this root canals were made in all the teeth to simulate the presence of lateral canals. After preparation, the teeth were randomly divided into two groups (n=10). In group I, the root canal system was filled directly after chemicalmechanical preparation; in group II, endodontic treatment was performed in multiple sessions, and after preparation the calcium hydroxide-based intracanal medication Calen® was inserted. After the period of 7 days, the root canals were vigorously irrigated and then they were filled. Next, the teeth were radiographed to verify the quality of the filling. The results demonstrated that the teeth treated in a single session, without calcium hydroxide medication, presented 47 canals out of 60 with radiographic evidence of filling, whereas the teeth in which intracanal medication was used, only 07 presented a radiographic image compatible with filling (p < 0.05). The use of the calcium hydroxide-based medication Calen made it difficult to obtain a hermetic filling of the root canal system. The clinical significance of this work basing on the fact that once the dentist knowing that property obliteration of calcium hydroxide can be taken care when they are used in the presence of lateral canals.

  12. Influence of a passive sonic irrigation system on the elimination of bacteria from root canal systems: a clinical study.

    Science.gov (United States)

    Huffaker, S Kirk; Safavi, Kamran; Spangberg, Larz S W; Kaufman, Blythe

    2010-08-01

    The present investigation evaluated the ability of a new passive sonic irrigation (sonic group) system (EndoActivator) to eliminate cultivable bacteria from root canals in vivo and compared it with that of standard syringe irrigation (control group). Data were obtained by using bacteriologic sampling of root canals treated by endodontic residents. Sampling results from 1 session of treatment were then compared with results obtained after intervisit calcium hydroxide disinfection and a second session of treatment. There was no significant difference in the ability of sonic group and control group to eliminate cultivable bacteria from root canals (P > .05). A second session and intervisit calcium hydroxide disinfection were able to eliminate cultivable bacteria from significantly more teeth than a single session of treatment (P treatment of apical periodontitis. Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  13. Effects of chemical alteration on fracture mechanical properties in hydrothermal systems

    Science.gov (United States)

    Callahan, O. A.; Eichhubl, P.; Olson, J. E.

    2015-12-01

    Fault and fracture networks often control the distribution of fluids and heat in hydrothermal and epithermal systems, and in related geothermal and mineral resources. Additional chemical influences on conduit evolution are well documented, with dissolution and precipitation of mineral species potentially changing the permeability of fault-facture networks. Less well understood are the impacts of chemical alteration on the mechanical properties governing fracture growth and fracture network geometry. We use double-torsion (DT) load relaxation tests under ambient air conditions to measure the mode-I fracture toughness (KIC) and subcritical fracture growth index (SCI) of variably altered rock samples obtained from outcrop in Dixie Valley, NV. Samples from southern Dixie Valley include 1) weakly altered granite, characterized by minor sericite in plagioclase, albitization and vacuolization of feldspars, and incomplete replacement of biotite with chlorite, and 2) granite from an area of locally intense propylitic alteration with chlorite-calcite-hematite-epidote assemblages. We also evaluated samples of completely silicified gabbro obtained from the Dixie Comstock epithermal gold deposit. In the weakly altered granite KIC and SCI are 1.3 ±0.2 MPam1/2 (n=8) and 59 ±25 (n=29), respectively. In the propylitic assemblage KIC is reduced to 0.6 ±0.1 MPam1/2 (n=11), and the SCI increased to 75 ±36 (n = 33). In both cases, the altered materials have lower fracture toughness and higher SCI than is reported for common geomechanical standards such as Westerly Granite (KIC ~1.7 MPam1/2; SCI ~48). Preliminary analysis of the silicified gabbro shows a significant increase in fracture toughness, 3.6 ±0.4 MPam1/2 (n=2), and SCI, 102 ±45 (n=19), compared to published values for gabbro (2.9 MPam1/2 and SCI = 32). These results suggest that mineralogical and textural changes associated with different alteration assemblages may result in spatially variable rates of fracture

  14. The effects of arbuscular mycorrhizal fungi and root interaction on the competition between Trifolium repens and Lolium perenne.

    Science.gov (United States)

    Ren, Haiyan; Gao, Tao; Hu, Jian; Yang, Gaowen

    2017-01-01

    Understanding the factors that alter competitive interactions and coexistence between plants is a key issue in ecological research. A pot experiment was conducted to test the effects of root interaction and arbuscular mycorrhizal fungi (AMF) inoculation on the interspecies competition between Trifolium repens and Lolium perenne under different proportions of mixed sowing by the combination treatment of two levels of AMF inoculation (inoculation and non-inoculation) and two levels of root interaction (root interaction and non-root interaction). Overall, the aboveground and belowground biomass of T. repens and L. perenne were not altered by AMF inoculation across planting ratios, probably because the fertile soil reduced the positive effect of AMF on plant growth. Both inter- and intraspecies root interaction significantly decreased the aboveground biomass of T. repens , but tended to increase the aboveground biomass of L. perenne across planting ratios, and thus peaked at the 4:4 polyculture. These results showed that T. repens competed poorly with L. perenne because of inter and intraspecies root interaction. Our results indicate that interspecies root interaction regulates the competitive ability of grass L. perenne and legume T. repens in mixtures and further makes great contribution for overyielding. Furthermore, AMF may not be involved in plant-plant interaction in fertile condition.

  15. The effects of arbuscular mycorrhizal fungi and root interaction on the competition between Trifolium repens and Lolium perenne

    Directory of Open Access Journals (Sweden)

    Haiyan Ren

    2017-12-01

    Full Text Available Understanding the factors that alter competitive interactions and coexistence between plants is a key issue in ecological research. A pot experiment was conducted to test the effects of root interaction and arbuscular mycorrhizal fungi (AMF inoculation on the interspecies competition between Trifolium repens and Lolium perenne under different proportions of mixed sowing by the combination treatment of two levels of AMF inoculation (inoculation and non-inoculation and two levels of root interaction (root interaction and non-root interaction. Overall, the aboveground and belowground biomass of T. repens and L. perenne were not altered by AMF inoculation across planting ratios, probably because the fertile soil reduced the positive effect of AMF on plant growth. Both inter- and intraspecies root interaction significantly decreased the aboveground biomass of T. repens, but tended to increase the aboveground biomass of L. perenne across planting ratios, and thus peaked at the 4:4 polyculture. These results showed that T. repens competed poorly with L. perenne because of inter and intraspecies root interaction. Our results indicate that interspecies root interaction regulates the competitive ability of grass L. perenne and legume T. repens in mixtures and further makes great contribution for overyielding. Furthermore, AMF may not be involved in plant–plant interaction in fertile condition.

  16. Salinity altered root distribution and increased diversity of bacterial communities in the rhizosphere soil of Jerusalem artichoke

    Science.gov (United States)

    Yang, Hui; Hu, Jinxiang; Long, Xiaohua; Liu, Zhaopu; Rengel, Zed

    2016-02-01

    The interaction between roots and bacterial communities in halophytic species is poorly understood. Here, we used Jerusalem artichoke cultivar Nanyu 1 (NY-1) to characterise root distribution patterns and determine diversity and abundance of bacteria in the rhizosphere soil under variable salinity. Root growth was not inhibited within the salinity range 1.2 to 1.9 g salt/kg, but roots were mainly confined to 0-20 cm soil layer vertically and 0-30 cm horizontally from the plant centre. Root concentrations of K+, Na+, Mg2+ and particularly Ca2+ were relatively high under salinity stress. High salinity stress decreased soil invertase and catalase activity. Using a next-generation, Illumina-based sequencing approach, we determined higher diversity of bacteria in the rhizosphere soil at high than low salinity. More than 15,500 valid reads were obtained, and Proteobacteria, Acidobacteria, Bacteroidetes and Actinobacteria predominated in all samples, accounting for >80% of the reads. On a genus level, 636 genera were common to the low and high salinity treatments at 0-5 cm and 5-10 cm depth. The abundance of Steroidobacter and Sphingomonas was significantly decreased by increasing salinity. Higher Shannon and Chao 1 indices with increasing severity of salt stress indicated that high salt stress increased diversity in the bacterial communities.

  17. Cadmium Toxicity Induced Alterations in the Root Proteome of Green Gram in Contrasting Response towards Iron Supplement

    Directory of Open Access Journals (Sweden)

    Sowbiya Muneer

    2014-04-01

    Full Text Available Cadmium signifies a severe threat to crop productivity and green gram is a notably iron sensitive plant which shows considerable variation towards cadmium stress. A gel-based proteomics analysis was performed with the roots of green gram exposed to iron and cadmium combined treatments. The resulting data show that twenty three proteins were down-regulated in iron-deprived roots either in the absence (−Fe/−Cd or presence (−Fe/+Cd of cadmium. These down-regulated proteins were however well expressed in roots under iron sufficient conditions, even in the presence of cadmium (+Fe/+Cd. The functional classification of these proteins determined that 21% of the proteins are associated with nutrient metabolism. The other proteins in higher quantities are involved in either transcription or translation regulation, and the rest are involved in biosynthesis metabolism, antioxidant pathways, molecular chaperones and stress response. On the other hand, several protein spots were also absent in roots in response to iron deprivation either in absence (−Fe/−Cd or presence (−Fe/+Cd of cadmium but were well expressed in the presence of iron (+Fe/+Cd. Results suggest that green gram plants exposed to cadmium stress are able to change the nutrient metabolic balance in roots, but in the mean time regulate cadmium toxicity through iron supplements.

  18. Distribution of linker histone variants during plant cell differentiation in the developmental zones of the maize root, dedifferentiation in callus culture after auxin treatment

    Directory of Open Access Journals (Sweden)

    ANASTASIOS ALATZAS

    2008-01-01

    Full Text Available Although several linker histone variants have been studied in both animal and plant organisms, little is known about their distribution during processes that involve alterations in chromatin function, such as differentiation, dedifferentiation and hormone treatment. In this study, we identified linker histone variants by using specific anti-histone Hl antibodies. Each variant's ratio to total Hl in the three developmental zones of maize (Zea mays L. root and in callus cultures derived from them was estimated in order to define possible alterations either during plant cell differentiation or during their dedifferentiation. We also evaluated linker histone variants' ratios in the developmental zones of maize roots treated with auxin in order to examine the effects of exogenous applied auxin to linker histone variant distribution. Finally, immunohistochemical detection was used to identify the root tissues containing each variant and correlate them with the physiological status of the plant cells. According to the results presented in this study, linker histone variants' ratios are altered in the developmental zones of maize root, while they are similar to the meristematic zone in samples from callus cultures and to the differentiation zone in samples from roots treated with auxin. We propose that the alterations in linker histone variants' ratios are correlated with plant cell differentiation and dedifferentiation.

  19. Effects of linuron on a rooted aquatic macrophyte in sediment-dosed test systems

    NARCIS (Netherlands)

    Buresova, H.; Crum, S.J.H.; Belgers, J.D.M.; Adriaanse, P.I.; Arts, G.H.P.

    2013-01-01

    Effects of linuron on the sediment-rooted aquatic macrophyte Myriophyllum spicatum L. were studied in sediment-dosed test systems following a proposed guideline with extended test duration. Sediment, pore water, overlying water and macrophyte shoots were sampled weekly for chemical analyses. Linuron

  20. Optimizing the chemical aspect of root canal irrigation

    OpenAIRE

    de Macedo, R.G.

    2013-01-01

    Root canal treatment is aimed at the removal of inflamed and infected tissue present in the root canal system. It will prevent the entrance of new microorganisms or nutrients in order to maintain or create a healthy environment around the root. There is sufficient evidence that shows that traditional endodontic therapy cannot make the root canal system completely free of bacteria. Moreover, it may not always result in complete healing of apical periodontitis, highlighting the need of optimizi...

  1. Comparison of Dentinal Crack Formation With Reciproc, Mtwo and ProTaper Root Canal Preparation Systems

    Directory of Open Access Journals (Sweden)

    Nazari Moghaddam

    2016-06-01

    Full Text Available Background Instrumentation with rotary instruments could potentially cause dentinal cracks possibly leading to tooth fracture. Reciproc files require a single file to finalize the root canal preparation and the effect of this procedure has not been compared with other systems. Objectives The aim of this study was to compare the incidence of dentinal micro-cracks following root canal preparations with ProTaper, Mtwo and Reciproc files. Materials and Methods In an experimental in vitro trial, 80 maxillary and mandibular first molars were selected and their crowns and distal roots were cut. The roots were then examined to remove any previous cracks and defects. An impression polyether material was used to simulate teeth periodontal ligament (PDL. The teeth were divided to four experimental groups (n = 20 and prepared using Reciproc, Mtwo and ProTaper or remained unprepared as a control group. The specimens were then sectioned horizontally on 3, 5 and 9 mm from the apex and number of micro-cracks was determined by stereomicroscope. The incidence of dentinal cracks on different systems or sections were statistically analyzed by means of the chi-square test. Results Dentinal defects on 3-mm, 5-mm and 9-mm sections from the apex were noted in 10 (5.6%; 7 (3.9% and 9 (5.0% samples of all, respectively. Following canal preparation using Reciproc, ProTaper and Mtwo systems, the defects were observed in 7 (3.9%, 12 (6.7% and 7 (3.9% the sections, respectively. No significant differences were observed regarding the defect incidence on the studied instrumentation files or sections. Conclusions Regarding the study limitations, dentinal cracks were observed in all files and distances from the apex. Although there was more crack incidence in ProTaper files, no significant differences were noted regarding the studied systems and sections from the apex.

  2. Altered gravity affects ventral root activity during fictive swimming and the static vestibuloocular reflex in young tadpoles (Xenopus laevis).

    Science.gov (United States)

    Böser, S; Dournon, C; Gualandris-Parisot, L; Horn, E

    2008-03-01

    During early periods of life, modifications of the gravitational environment affect the development of sensory, neuronal and motor systems. The vestibular system exerts significant effects on motor networks that control eye and body posture as well as swimming. The objective of the present study was to study whether altered gravity (AG) affects vestibuloocular and spinal motor systems in a correlated manner. During the French Soyuz taxi flight Andromède to the International Space Station ISS (launch: October 21, 2001; landing: October 31, 2001) Xenopus laevis embryos were exposed for 10 days to microgravity (microg). In addition, a similar experiment with 3g-hypergravity (3g) was performed in the laboratory. At onset of AG, embryos had reached developmental stages 24 to 27. After exposure to AG, each tadpole was tested for its roll-induced vestibuloocular reflex (rVOR) and 3 hours later it was tested for the neuronal activity recorded from the ventral roots (VR) during fictive swimming. During the post-AG recording periods tadpoles had reached developmental stages 45 to 47. It was observed that microgravity affected VR activity during fictive swimming and rVOR. In particular, VR activity changes included a significant decrease of the rostrocaudal delay and a significant increase of episode duration. The rVOR-amplitude was transiently depressed. Hypergravity was less effective on the locomotor pattern; occurring effects on fictive swimming were the opposite of microg effects. As after microgravity, the rVOR was depressed after 3g-exposure. All modifications of the rVOR and VR-activity recovered to normal levels within 4 to 7 days after termination of AG. Significant correlations between the rVOR amplitude and VR activity of respective tadpoles during the recording period have been observed in both tadpoles with or without AG experience. The data are consistent with the assumptions that during this period of life which is characterized by a progressive development

  3. A heterogeneous boron distribution in soil influences the poplar root system architecture development

    Science.gov (United States)

    Rees, R.; Robinson, B. H.; Hartmann, S.; Lehmann, E.; Schulin, R.

    2009-04-01

    Poplars are well suited for the phytomanagement of boron (B)-contaminated sites, due to their high transpiration rate and tolerance to elevated soil B concentrations. However, the uptake and the fate of B in poplar stands are not well understood. This information is crucial to improve the design of phytomanagement systems, where the primary role of poplars is to reduce B leaching by reducing the water flux through the contaminated material. Like other trace elements, B occurs heterogeneously in soils. Concentrations can differ up to an order of magnitude within centimetres. These gradients affect plant root growth and thus via preferential flow along the roots water and mass transport in soils to ground and surface waters. Generally there are three possible reactions of plant roots to patches with elevated trace element concentrations in soils: indifference, avoidance, or foraging. While avoidance or indifference might seem to be the most obvious strategies, foraging cannot be excluded a priori, because of the high demand of poplars for B compared to other tree species. We aimed to determine the rooting strategies of poplars in soils where B is either homo- or heterogeneously distributed. We planted 5 cm cuttings of Populus tremula var. Birmensdorf clones in aluminum (Al) containers with internal dimensions of 64 x 67 x 1.2 cm. The soil used was subsoil from northern Switzerland with a naturally low B and organic C concentration. We setup two treatments and a control with three replicates each. We spiked a bigger and a smaller portion of the soil with the same amount of B(OH)3-salt, in order to obtain soil concentrations of 7.5 mg B kg-1 and 20 mg B kg-1. We filled the containers with (a) un-spiked soil, (b) the 7.5 mg B kg-1 soil and (c) heterogeneously. The heterogeneous treatment consisted of one third 20 mg B kg-1 soil and two thirds control soil. We grew the poplars in a small greenhouse over 2 months and from then on in a climate chamber for another 3 months

  4. Do shallow soil, low water availability, or their combination increase the competition between grasses with different root systems in karst soil?

    Science.gov (United States)

    Zhao, Yajie; Li, Zhou; Zhang, Jing; Song, Haiyan; Liang, Qianhui; Tao, Jianping; Cornelissen, Johannes H C; Liu, Jinchun

    2017-04-01

    Uneven soil depth and low water availability are the key limiting factors to vegetation restoration and reconstruction in limestone soils such as in vulnerable karst regions. Belowground competition will possibly increase under limited soil resources. Here, we investigate whether low resource availability (including shallow soil, low water availability, and shallow soil and low water availability combined) stimulates the competition between grasses with different root systems in karst soil, by assessing their growth response, biomass allocation, and morphological plasticity. In a full three-way factorial blocked design of soil depth by water availability by neighbor identity, we grew Festuca arundinacea (deep-rooted) and Lolium perenne (shallow-rooted) under normal versus shallow soil depth, high versus low water availability, and in monoculture (conspecific neighbor) versus mixture (neighbor of the other species). The key results were as follows: (1) total biomass and aboveground biomass in either of the species decreased with reduction of resources but were not affected by planting patterns (monoculture or mixture) even at low resource levels. (2) For F. arundinacea, root biomass, root mass fraction, total root length, and root volume were higher in mixture than in monoculture at high resource level (consistent with resource use complementarity), but lower in mixture than in monoculture at low resource levels (consistent with interspecific competition). In contrast for L. perenne, either at high or low resource level, these root traits had mostly similar values at both planting patterns. These results suggest that deep-rooted and shallow-rooted plant species can coexist in karst regions under current climatic regimes. Declining resources, due to shallow soil, a decrease in precipitation, or combined shallow soil and karst drought, increased the root competition between plants of deep-rooted and shallow-rooted species. The root systems of deep-rooted plants may be

  5. The graphics editor in ROOT

    International Nuclear Information System (INIS)

    Antcheva, Ilka; Brun, Rene; Hof, Carsten; Rademakers, Fons

    2006-01-01

    A well-designed Graphical User Interface (GUI) has critical importance in any computer application. The user interface is where the end users and the complex system intersect. An effective interface design can make a powerful and complex system, such as ROOT, easy and intuitive to learn and operate. This paper describes the main goals we defined and the design solution we found developing the graphics editor in ROOT

  6. The inflow of Cs-137 in soil with root litter and root exudates of Scots pine

    Science.gov (United States)

    Shcheglov, Alexey; Tsvetnova, Olga; Popova, Evgenia

    2017-04-01

    In the model experiment on evaluation of Cs-137 inflow in the soil with litter of roots and woody plants root exudates on the example of soil and water cultures of Scots pine (Pinus sylvestris L.) was shown, that through 45 days after the deposit Cs-137 solution on pine needles (specific activity of solution was 3.718*106 Bk) of the radionuclide in all components of model systems has increased significantly: needles, small branches and trunk by Cs-137 surface contamination during the experiment; roots as a result of the internal distribution of the radionuclide in the plant; soil and soil solution due to the of receipt Cs-137 in the composition of root exudates and root litter. Over 99% of the total reserve of Cs-137 accumulated in the components of the soil and water systems, accounted for bodies subjected to external pollution (needles and small branches) and soil solution, haven't been subjected to surface contamination. At the same contamination of soil and soil solution by Cs-137 in the model experiment more than a> 99.9% was due to root exudates

  7. An In-Situ Root-Imaging System in the Context of Surface Detection of CO2

    Science.gov (United States)

    Apple, M. E.; Prince, J. B.; Bradley, A. R.; Zhou, X.; Lakkaraju, V. R.; Male, E. J.; Pickles, W.; Thordsen, J. J.; Dobeck, L.; Cunningham, A.; Spangler, L.

    2009-12-01

    Carbon sequestration is a valuable method of spatially confining CO2 belowground. The Zero Emissions Research Technology, (ZERT), site is an experimental facility in a former agricultural field on the Montana State University campus in Bozeman, Montana, where CO2 was experimentally released at a rate of 200kg/day in 2009 into a 100 meter underground injection well running parallel to the ground surface. This injection well, or pipe, has deliberate leaks at intervals, and CO2 travels from these leaks upward to the surface of the ground. The ZERT site is a model system designed with the purpose of testing methods of surface detection of CO2. One important aspect of surface detection is the determination of the effects of CO2 on the above and belowground portions of plants growing above sequestration fields. At ZERT, these plants consist of a pre-existing mixture of herbaceous species present at the agricultural field. Species growing at the ZERT site include several grasses, Dactylis glomerata (Orchard Grass), Poa pratensis (Kentucky Bluegrass), and Bromus japonicus (Japanese Brome); the nitrogen-fixing legumes Medicago sativa, (Alfalfa), and Lotus corniculatus, (Birdsfoot trefoil); and an abundance of Taraxacum officinale, (Dandelion). Although the aboveground parts of the plants at high CO2 are stressed, as indicated by changes in hyperspectral plant signatures, leaf fluorescence and leaf chlorophyll content, we are interested in determining whether the roots are also stressed. To do so, we are combining measurements of soil conductivity and soil moisture with root imaging. We are using an in-situ root-imaging system manufactured by CID, Inc. (Camas, WA), along with image analysis software (Image-J) to analyze morphometric parameters in the images and to determine what effects, if any, the presence of leaking and subsequently upwelling CO2 has on the phenology of root growth, growth and turnover of individual fine and coarse roots, branching patterns, and root

  8. Anchorage failure of young trees in sandy soils is prevented by a rigid central part of the root system with various designs

    Science.gov (United States)

    Danquechin Dorval, Antoine; Meredieu, Céline; Danjon, Frédéric

    2016-01-01

    Background and Aims Storms can cause huge damage to European forests. Even pole-stage trees with 80-cm rooting depth can topple. Therefore, good anchorage is needed for trees to survive and grow up from an early age. We hypothesized that root architecture is a predominant factor determining anchorage failure caused by strong winds. Methods We sampled 48 seeded or planted Pinus pinaster trees of similar aerial size from four stands damaged by a major storm 3 years before. The trees were gathered into three classes: undamaged, leaning and heavily toppled. After uprooting and 3D digitizing of their full root architectures, we computed the mechanical characteristics of the main components of the root system from our morphological measurements. Key Results Variability in root architecture was quite large. A large main taproot, either short and thick or long and thin, and guyed by a large volume of deep roots, was the major component that prevented stem leaning. Greater shallow root flexural stiffness mainly at the end of the zone of rapid taper on the windward side also prevented leaning. Toppling in less than 90-cm-deep soil was avoided in trees with a stocky taproots or with a very big leeward shallow root. Toppled trees also had a lower relative root biomass – stump excluded – than straight trees. Conclusions It was mainly the flexural stiffness of the central part of the root system that secured anchorage, preventing a weak displacement of the stump. The distal part of the longest taproot and attached deep roots may be the only parts of the root system contributing to anchorage through their maximum tensile load. Several designs provided good anchorage, depending partly on available soil depth. Pole-stage trees are in-between the juvenile phase when they fail by toppling and the mature phase when they fail by uprooting. PMID:27456136

  9. Cover crop root, shoot, and rhizodeposit contributions to soil carbon in a no- till corn bioenergy cropping system

    Science.gov (United States)

    Austin, E.; Grandy, S.; Wickings, K.; McDaniel, M. D.; Robertson, P.

    2016-12-01

    Crop residues are potential biofuel feedstocks, but residue removal may result in reduced soil carbon (C). The inclusion of a cover crop in a corn bioenergy system could provide additional biomass and as well as help to mitigate the negative effects of residue removal by adding belowground C to stable soil C pools. In a no-till continuous corn bioenergy system in the northern portion of the US corn belt, we used 13CO2 pulse labeling to trace C in a winter rye (secale cereale) cover crop into different soil C pools for two years following rye termination. Corn stover contributed 66 (another 163 was in harvested corn stover), corn roots 57, rye shoot 61, rye roots 59, and rye rhizodeposits 27 g C m-2 to soil C. Five months following cover crop termination, belowground cover crop inputs were three times more likely to remain in soil C pools and much of the root-derived C was in mineral- associated soil fractions. Our results underscore the importance of cover crop roots vs. shoots as a source of soil C. Belowground C inputs from winter cover crops could substantially offset short term stover removal in this system.

  10. Effect of channel size on sweet potato storage root enlargement in the Tuskegee University hydroponic nutrient film system

    Science.gov (United States)

    Morris, Carlton E.; Martinez, Edwin; Bonsi, C. K.; Mortley, Desmond G.; Hill, Walter A.; Ogbuehi, Cyriacus R.; Loretan, Phil A.

    1989-01-01

    The potential of the sweet potato as a food source for future long term manned space missions is being evaluated for NASA's Controlled Ecological Life Support Systems (CELSS) program. Sweet potatoes have been successfully grown in a specially designed Tuskegee University nutrient film technique (TU NFT) system. This hydroponic system yielded storage roots as high as 1790 g/plant fresh weight. In order to determine the effect of channel size on the yield of sweet potatoes, the width and depth of the growing channels were varied in two separate experiments. Widths were studied using the rectangular TU NFT channels with widths of 15 cm (6 in), 30 cm (12 in) and 45 cm (18 in). Channel depths of 5 cm (2 in), 10 cm (4 in), and 15 cm (6 in) were studied using a standard NASA fan shaped Biomass Production Chamber (BPC) channel. A comparison of preliminary results indicated that, except for storage root number, the growth and yield of sweet potatoes were not affected by channel width. Storage root yield was affected by channel depth although storage root number and foliage growth were not. Both experiments are being repeated.

  11. Structure, root systems and periodicity of savanna plants and vegetations in Northern Surinam

    NARCIS (Netherlands)

    Donselaar-ten Bokkel Huinink, van W.A.E.

    1966-01-01

    From July 1958 to May 1959 an investigation was carried out of the relation between physiognomic characteristics of the vegetation and the habitat on some savannas in the vicinity of Zanderij, Surinam. Root systems, structure, periodicity and characteristics of the leaves were considered, both of

  12. To evaluate and compare the efficacy, cleaning ability of hand and two rotary systems in root canal retreatment.

    Science.gov (United States)

    Shivanand, Sunita; Patil, Chetan R; Thangala, Venugopal; Kumar, Pabbati Ravi; Sachdeva, Jyoti; Krishna, Akash

    2013-05-01

    To evaluate and compare the efficacy, cleaning ability of hand and two rotary systems in root canal retreatment. Sixty extracted premolars were retreated with following systems: Group -ProTaper Universal retreatment files, Group 2-ProFile system, Group 3-H-file. Specimens were split longitudinally and amount of remaining gutta-percha on the canal walls was assessed using direct visual scoring with the aid of stereomicroscope. Results were statistically analyzed using ANOVA test. Completely clean root canal walls were not achieved with any of the techniques investigated. However, all three systems proved to be effective for gutta-percha removal. Significant difference was found between ProTaper universal retreatment file and H-file, and also between ProFile and H-file. Under the conditions of the present study, ProTaper Universal retreatment files left significantly less guttapercha and sealer than ProFile and H-file. Rotary systems in combination with gutta-percha solvents can perform superiorly as compared to the time tested traditional hand instrumentation in root canal retreatment.

  13. Mercury-induced biochemical and proteomic changes in rice roots.

    Science.gov (United States)

    Chen, Yun-An; Chi, Wen-Chang; Huang, Tsai-Lien; Lin, Chung-Yi; Quynh Nguyeh, Thi Thuy; Hsiung, Yu-Chywan; Chia, Li-Chiao; Huang, Hao-Jen

    2012-06-01

    Mercury (Hg) is a serious environmental pollution threats to the planet. Accumulation of Hg in plants disrupts many cellular-level functions and inhibits growth and development, but the mechanism is not fully understood. We investigated cellular, biochemical and proteomic changes in rice roots under Hg stress. Root growth rate was decreased and Hg, reactive oxygen species (ROS), and malondialdehyde (MDA) content and lipoxygenase activity were increased significantly with increasing Hg concentration in roots. We revealed a time-dependent alteration in total glutathione content and enzymatic activity of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) and peroxidase (POD) during Hg stress. 2-D electrophoresis revealed differential expression of 25 spots with Hg treatment of roots: 14 spots were upregulated and 11 spots downregulated. These differentially expressed proteins were identified by ESI-MS/MS to be involved in cellular functions including redox and hormone homeostasis, chaperone activity, metabolism, and transcription regulation. These results may provide new insights into the molecular basis of the Hg stress response in plants. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  14. Pulp regeneration in a full-length human tooth root using a hierarchical nanofibrous microsphere system.

    Science.gov (United States)

    Li, Xiangwei; Ma, Chi; Xie, Xiaohua; Sun, Hongchen; Liu, Xiaohua

    2016-04-15

    While pulp regeneration using tissue engineering strategy has been explored for over a decade, successful regeneration of pulp tissues in a full-length human root with a one-end seal that truly simulates clinical endodontic treatment has not been achieved. To address this challenge, we designed and synthesized a unique hierarchical growth factor-loaded nanofibrous microsphere scaffolding system. In this system, vascular endothelial growth factor (VEGF) binds with heparin and is encapsulated in heparin-conjugated gelatin nanospheres, which are further immobilized in the nanofibers of an injectable poly(l-lactic acid) (PLLA) microsphere. This hierarchical microsphere system not only protects the VEGF from denaturation and degradation, but also provides excellent control of its sustained release. In addition, the nanofibrous PLLA microsphere integrates the extracellular matrix-mimicking architecture with a highly porous injectable form, efficiently accommodating dental pulp stem cells (DPSCs) and supporting their proliferation and pulp tissue formation. Our in vivo study showed the successful regeneration of pulp-like tissues that fulfilled the entire apical and middle thirds and reached the coronal third of the full-length root canal. In addition, a large number of blood vessels were regenerated throughout the canal. For the first time, our work demonstrates the success of pulp tissue regeneration in a full-length root canal, making it a significant step toward regenerative endodontics. The regeneration of pulp tissues in a full-length tooth root canal has been one of the greatest challenges in the field of regenerative endodontics, and one of the biggest barriers for its clinical application. In this study, we developed a unique approach to tackle this challenge, and for the first time, we successfully regenerated living pulp tissues in a full-length root canal, making it a significant step toward regenerative endodontics. This study will make positive scientific

  15. 76 FR 4471 - Privacy Act of 1974; Report of Modified or Altered System of Records

    Science.gov (United States)

    2011-01-25

    ... 1974; Report of Modified or Altered System of Records AGENCY: Division of Respiratory Disease Studies... System of Records. SUMMARY: The Department of Health and Human Services proposes to alter System of... System of Records will be effective 40 days from the date submitted to the OMB, unless NIOSH receives...

  16. Effect of Metal Artifacts on Detection of Vertical Root Fractures Using Two Cone Beam Computed Tomography Systems.

    Science.gov (United States)

    Safi, Yaser; Aghdasi, Mohammad Mehdi; Ezoddini-Ardakani, Fatemeh; Beiraghi, Samira; Vasegh, Zahra

    2015-01-01

    Vertical root fracture (VRF) is common in endodontically treated teeth. Conventional and digital radiographies have limitations for detection of VRFs. Cone-beam computed tomography (CBCT) offers greater detection accuracy of VRFs in comparison with conventional radiography. This study compared the effects of metal artifacts on detection of VRFs by using two CBCT systems. Eighty extracted premolars were selected and sectioned at the level of the cemento enamel junction (CEJ). After preparation, root canals were filled with gutta-percha. Subsequently, two thirds of the root fillings were removed for post space preparation and a custom-made post was cemented into each canal. The teeth were randomly divided into two groups (n=40). In the test group, root fracture was created with Instron universal testing machine. The control teeth remained intact. CBCT scans of all teeth were obtained with either New Tom VGI or Soredex Scanora 3D. Three observers analyzed the images for detection of VRF. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for VRF detection and percentage of probable cases were calculated for each imaging system and compared using non-parametric tests considering the non-normal distribution of data. The inter-observer reproducibility was calculated using the weighted kappa coefficient. There were no statistically significant differences in sensitivity, specificity, PPV and NPV between the two CBCT systems. The effect of metal artifacts on VRF detection was not significantly different between the two CBCT systems.

  17. A novel interaction between plant-beneficial rhizobacteria and roots: colonization induces corn resistance against the root herbivore Diabrotica speciosa.

    Directory of Open Access Journals (Sweden)

    Franciele Santos

    Full Text Available A number of soil-borne microorganisms, such as mycorrhizal fungi and rhizobacteria, establish mutualistic interactions with plants, which can indirectly affect other organisms. Knowledge of the plant-mediated effects of mutualistic microorganisms is limited to aboveground insects, whereas there is little understanding of what role beneficial soil bacteria may play in plant defense against root herbivory. Here, we establish that colonization by the beneficial rhizobacterium Azospirillum brasilense affects the host selection and performance of the insect Diabrotica speciosa. Root larvae preferentially orient toward the roots of non-inoculated plants versus inoculated roots and gain less weight when feeding on inoculated plants. As inoculation by A. brasilense induces higher emissions of (E-β-caryophyllene compared with non-inoculated plants, it is plausible that the non-preference of D. speciosa for inoculated plants is related to this sesquiterpene, which is well known to mediate belowground insect-plant interactions. To the best of our knowledge, this is the first study showing that a beneficial rhizobacterium inoculant indirectly alters belowground plant-insect interactions. The role of A. brasilense as part of an integrative pest management (IPM program for the protection of corn against the South American corn rootworm, D. speciosa, is considered.

  18. 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...

  19. Periapical repair after root canal filling with different root canal sealers.

    Science.gov (United States)

    Tanomaru-Filho, Mário; Tanomaru, Juliane Maria Guerreiro; Leonardo, Mario Roberto; da Silva, Lea Assed Bezerra

    2009-01-01

    The aim of this study was to evaluate periapical repair after root canal filling with different endodontic sealers. Sixty-four root canals from dog s teeth were filled, divided into 4 groups (n=16). Root canals were instrumented with K-type files and irrigated with 1% sodium hypochlorite solution. Root canals were filled in the same session by active lateral condensation of the cones and sealers: Intrafill, AH Plus, Roeko Seal and Resilon/Epiphany System. After 90 days, the animals were euthanized and the tissues to be evaluated were processed and stained with hematoxylin and eosin. For histopathological analysis, the following parameters were evaluated: inflammatory process, mineralized tissue resorption, and apical mineralized tissue deposition. Histopathological analysis demonstrated that Intrafill had less favorable results in terms of apical and periapical repair, compared to the other sealers (p0.05). In conclusion, AH Plus and the materials Roeko Seal and Epiphany are good options for clinical use in Endodontics.

  20. Endodontic management of a mandibular first molar with six root canal systems.

    Science.gov (United States)

    Jain, Dilip; Reddy, Smitha; Venigalla, Bhuvan Shome; Kamishetty, Shekhar

    2015-01-01

    Internal anatomy of pulp is complex. The first mandibular molars typically have two roots, one mesial with two root canals and another distal root, which contains one or two canals. A 20-year-old female patient reported with intermittent pain and incomplete root canal treatment in left lower back region since 1-week. Refined access cavity revealed initially two canals in mesial and two canals in the distal root. With operating microscope and cone beam computerized tomography, two additional canals (L-mesio-buccal and B-mesio-lingual) were identified in mesial root. One-year follow-up showed patient was asymptomatic and complete healing of periapical radiolucency.

  1. Tests of a system to exclude roots from buried radioactive waste in a warm, humid climate

    International Nuclear Information System (INIS)

    Murphy, C.E. Jr.; Corey, J.C.; Adriano, D.C.; Decker, O.D.; Griggs, R.D.

    1989-01-01

    Vegetation is commonly used to stabilize the ground covering buried waste sites. However, constituents of buried waste can be brought to the surface if the waste is penetrated by plant roots. An ideal waste burial system would allow the use of vegetation to stabilize the soil above the buried waste but would exclude roots from the waste. One system that shows considerable promise is a slow release encapsulation of a root growth inhibitor (Trifluralin). Projected lifetimes of the capsule are in the order of 100 years. The capsule is bonded to a geotextile, which provides an easy means of distributing the capsule evenly over the area to be protected. Vegetation grown in the soil above the barrier has provided good ground cover, although some decrease in growth has been found in some species. Of the species tested the sensitivity to the biobarrier, as measured by the distance root growth stops near the barrier, is bamboo> bahia grass> bermuda grass> soybean. Potential uses for the biobarrier at the Savannah River Site (SRS) include the protection of clay caps over buried, low-level saltstone and protection of gravel drains and clay caps over decommissioned seepage basins. Trails of the biobarrier as part of waste site caps are scheduled to begin during the next 12 months

  2. Jatropha curcas L. Root Structure and Growth in Diverse Soils

    Science.gov (United States)

    Valdés-Rodríguez, Ofelia Andrea; Sánchez-Sánchez, Odilón; Pérez-Vázquez, Arturo; Caplan, Joshua S.; Danjon, Frédéric

    2013-01-01

    Unlike most biofuel species, Jatropha curcas has promise for use in marginal lands, but it may serve an additional role by stabilizing soils. We evaluated the growth and structural responsiveness of young J. curcas plants to diverse soil conditions. Soils included a sand, a sandy-loam, and a clay-loam from eastern Mexico. Growth and structural parameters were analyzed for shoots and roots, although the focus was the plasticity of the primary root system architecture (the taproot and four lateral roots). The sandy soil reduced the growth of both shoot and root systems significantly more than sandy-loam or clay-loam soils; there was particularly high plasticity in root and shoot thickness, as well as shoot length. However, the architecture of the primary root system did not vary with soil type; the departure of the primary root system from an index of perfect symmetry was 14 ± 5% (mean ± standard deviation). Although J. curcas developed more extensively in the sandy-loam and clay-loam soils than in sandy soil, it maintained a consistent root to shoot ratio and root system architecture across all types of soil. This strong genetic determination would make the species useful for soil stabilization purposes, even while being cultivated primarily for seed oil. PMID:23844412

  3. Jatropha curcas L. root structure and growth in diverse soils.

    Science.gov (United States)

    Valdés-Rodríguez, Ofelia Andrea; Sánchez-Sánchez, Odilón; Pérez-Vázquez, Arturo; Caplan, Joshua S; Danjon, Frédéric

    2013-01-01

    Unlike most biofuel species, Jatropha curcas has promise for use in marginal lands, but it may serve an additional role by stabilizing soils. We evaluated the growth and structural responsiveness of young J. curcas plants to diverse soil conditions. Soils included a sand, a sandy-loam, and a clay-loam from eastern Mexico. Growth and structural parameters were analyzed for shoots and roots, although the focus was the plasticity of the primary root system architecture (the taproot and four lateral roots). The sandy soil reduced the growth of both shoot and root systems significantly more than sandy-loam or clay-loam soils; there was particularly high plasticity in root and shoot thickness, as well as shoot length. However, the architecture of the primary root system did not vary with soil type; the departure of the primary root system from an index of perfect symmetry was 14 ± 5% (mean ± standard deviation). Although J. curcas developed more extensively in the sandy-loam and clay-loam soils than in sandy soil, it maintained a consistent root to shoot ratio and root system architecture across all types of soil. This strong genetic determination would make the species useful for soil stabilization purposes, even while being cultivated primarily for seed oil.

  4. Jatropha curcas L. Root Structure and Growth in Diverse Soils

    Directory of Open Access Journals (Sweden)

    Ofelia Andrea Valdés-Rodríguez

    2013-01-01

    Full Text Available Unlike most biofuel species, Jatropha curcas has promise for use in marginal lands, but it may serve an additional role by stabilizing soils. We evaluated the growth and structural responsiveness of young J. curcas plants to diverse soil conditions. Soils included a sand, a sandy-loam, and a clay-loam from eastern Mexico. Growth and structural parameters were analyzed for shoots and roots, although the focus was the plasticity of the primary root system architecture (the taproot and four lateral roots. The sandy soil reduced the growth of both shoot and root systems significantly more than sandy-loam or clay-loam soils; there was particularly high plasticity in root and shoot thickness, as well as shoot length. However, the architecture of the primary root system did not vary with soil type; the departure of the primary root system from an index of perfect symmetry was 14±5% (mean ± standard deviation. Although J. curcas developed more extensively in the sandy-loam and clay-loam soils than in sandy soil, it maintained a consistent root to shoot ratio and root system architecture across all types of soil. This strong genetic determination would make the species useful for soil stabilization purposes, even while being cultivated primarily for seed oil.

  5. Evolutionary potential of root chemical defense: genetic correlations with shoot chemistry and plant growth.

    Science.gov (United States)

    Parker, J D; Salminen, J-P; Agrawal, Anurag A

    2012-08-01

    Root herbivores can affect plant fitness, and roots often contain the same secondary metabolites that act as defenses in shoots, but the ecology and evolution of root chemical defense have been little investigated. Here, we investigated genetic variance, heritability, and correlations among defensive phenolic compounds in shoot vs. root tissues of common evening primrose, Oenothera biennis. Across 20 genotypes, there were roughly similar concentrations of total phenolics in shoots vs. roots, but the allocation of particular phenolics to shoots vs. roots varied along a continuum of genotype growth rate. Slow-growing genotypes allocated 2-fold more of the potential pro-oxidant oenothein B to shoots than roots, whereas fast-growing genotypes had roughly equivalent above and belowground concentrations. Phenolic concentrations in both roots and shoots were strongly heritable, with mostly positive patterns of genetic covariation. Nonetheless, there was genotype-specific variation in the presence/absence of two major ellagitannins (oenothein A and its precursor oenothein B), indicating two different chemotypes based on alterations in this chemical pathway. Overall, the presence of strong genetic variation in root defenses suggests ample scope for the evolution of these compounds as defenses against root herbivores.

  6. Root causes occurrence of low BIM adoption in Malaysia: System dynamics modelling approach

    Science.gov (United States)

    Mamter, Shahela; Aziz, Abdul Rashid Abdul; Zulkepli, Jafri

    2017-11-01

    The global implementation of BIM in the construction field is increasing worldwide. Due to the advantages offered by BIM, its implementation is considered important in the construction projects. Nevertheless, the Construction Industry Transformation Plan has reported that the adoption of Building Information Modelling (BIM) in Malaysia is still low and it is estimated at only 10 percent adoption amongst construction stake players. The barriers influencing the occurrence of low adoption BIM in Malaysia have been studied by some researchers. However, these researchers did not investigate the root causes which might lead to the recurring of the barriers to BIM adoption. Root causes that immediately occurrence of barriers, also known as precipitants or trigger causes. This conceptual paper developed the causal loop diagram (CLD) which presents the relationship between the perceived variables using system dynamic modelling approach. The findings revealed a novelty validated diagrams that design the holistic dynamic relationship on the root causes occurrence of low BIM adoption. Nonetheless, the diagram subject to more empirical testing for its practicability and further refinement upon more results expected to emerge as the research progresses.

  7. Drought Stress Results in a Compartment-Specific Restructuring of the Rice Root-Associated Microbiomes

    Directory of Open Access Journals (Sweden)

    Christian Santos-Medellín

    2017-07-01

    Full Text Available Plant roots support complex microbial communities that can influence plant growth, nutrition, and health. While extensive characterizations of the composition and spatial compartmentalization of these communities have been performed in different plant species, there is relatively little known about the impact of abiotic stresses on the root microbiota. Here, we have used rice as a model to explore the responses of root microbiomes to drought stress. Using four distinct genotypes, grown in soils from three different fields, we tracked the drought-induced changes in microbial composition in the rhizosphere (the soil immediately surrounding the root, the endosphere (the root interior, and unplanted soils. Drought significantly altered the overall bacterial and fungal compositions of all three communities, with the endosphere and rhizosphere compartments showing the greatest divergence from well-watered controls. The overall response of the bacterial microbiota to drought stress was taxonomically consistent across soils and cultivars and was primarily driven by an enrichment of multiple Actinobacteria and Chloroflexi, as well as a depletion of several Acidobacteria and Deltaproteobacteria. While there was some overlap in the changes observed in the rhizosphere and endosphere communities, several drought-responsive taxa were compartment specific, a pattern likely arising from preexisting compositional differences, as well as plant-mediated processes affecting individual compartments. These results reveal that drought stress, in addition to its well-characterized effects on plant physiology, also results in restructuring of root microbial communities and suggest the possibility that constituents of the altered plant microbiota might contribute to plant survival under extreme environmental conditions.

  8. 78 FR 64196 - Privacy Act Altered System of Records

    Science.gov (United States)

    2013-10-28

    ... records to COMMERCE/DEPARTMENT-20, Biographical Files and Social Networks. The amendment serves to modify... DEPARTMENT OF COMMERCE [Docket No. 130730666-3877-02] Privacy Act Altered System of Records AGENCY: Department of Commerce. ACTION: Notice; Commerce/Department-20, Biographical Files. SUMMARY: The Department...

  9. Computed tomography scanning can monitor the effects of soil medium on root system development: An example of salt stress in corn

    Directory of Open Access Journals (Sweden)

    Sowmyalakshmi eSubramanian

    2015-04-01

    Full Text Available Seeds and young seedlings often encounter high soluble salt levels in the upmost soil layers, impeding vigorous growth by affecting root establishment. Computed tomography (CT scanning used at low X-ray doses can help study root development in such conditions non-destructively, because plants are allowed to grow throughout the experiment. Using a high-resolution Toshiba XVision CT scanner, we studied corn (Zea mays L. root growth under optimal and salt-stressed conditions in 3D and on a weekly basis over 3 weeks. Two groups of 3 corn plants were grown in the controlled environment of a growth chamber, in mid-sized plastic pots filled with sieved and autoclaved sand. Seedlings were subjected to first CT scanning one week after seed planting. Our main research objectives concerning root systems were: (i to quantify structural complexity from fractal dimensions estimated on skeletal 3-D images built from CT scanning data; (ii to measure growth from volumes and derived relative rates, after isolating primary and secondary roots from the soil medium in CT scanning data; and (iii to assess differences in complexity and growth per week and over Weeks 1–3 for groups of corn plants. Differences between groups were present from Week 1; starting in Week 2 secondary roots were present and could be isolated, which refined the complexity and growth analyses of root systems. Besides expected Week main effects (P < 0.01 or 0.05, Week x Group interaction (P < 0.05 or 0.10 and Group main effects were observed, which is remarkable given the small sample sizes. Graphical, quantitative and statistical analyses of CT scanning data were thus completed at an unprecedented level, and provided new and important insights regarding root system development. Repeated CT scanning is the key to a better understanding of the establishment in the soil medium of crop plants such as corn and the assessment of salt stress effects on developing root systems, in complexity and

  10. Orthodontic tooth movement and root resorption in ovariectomized rats treated by systemic administration of zoledronic acid.

    Science.gov (United States)

    Sirisoontorn, Irin; Hotokezaka, Hitoshi; Hashimoto, Megumi; Gonzales, Carmen; Luppanapornlarp, Suwannee; Darendeliler, M Ali; Yoshida, Noriaki

    2012-05-01

    The effect of zoledronic acid, a potent and novel bisphosphonate, on tooth movement and orthodontically induced root resorption in osteoporotic animals systemically treated with zoledronic acid as similarly used in postmenopausal patients has not been elucidated. Therefore, this study was undertaken. Fifteen 10-week-old female Wistar rats were divided into 3 groups: ovariectomy, ovariectomy + zoledronic acid, and control. Only the ovariectomy and ovariectomy + zoledronic acid groups underwent ovariectomies. Two weeks after the ovariectomy, zoledronic acid was administered only to the ovariectomy + zoledronic acid group. Four weeks after the ovariectomy, 25-g nickel-titanium closed-coil springs were applied to observe tooth movement and orthodontically induced root resorption. There were significant differences in the amounts of tooth movement and orthodontically induced root resorption between the ovariectomy and the control groups, and also between the ovariectomy and the ovariectomy + zoledronic acid groups. There was no statistically significant difference in tooth movement and orthodontically induced root resorption between the ovariectomy + zoledronic acid and the control groups. Zoledronic acid inhibited significantly more tooth movement and significantly reduced the severity of orthodontically induced root resorption in the ovariectomized rats. The ovariectomy + zoledronic acid group showed almost the same results as did the control group in both tooth movement and orthodontically induced root resorption. Zoledronic acid inhibits excessive orthodontic tooth movement and also reduces the risk of severe orthodontically induced root resorption in ovariectomized rats. Copyright © 2012 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  11. Impact of DNA mismatch repair system alterations on human fertility and related treatments.

    Science.gov (United States)

    Hu, Min-hao; Liu, Shu-yuan; Wang, Ning; Wu, Yan; Jin, Fan

    2016-01-01

    DNA mismatch repair (MMR) is one of the biological pathways, which plays a critical role in DNA homeostasis, primarily by repairing base-pair mismatches and insertion/deletion loops that occur during DNA replication. MMR also takes part in other metabolic pathways and regulates cell cycle arrest. Defects in MMR are associated with genomic instability, predisposition to certain types of cancers and resistance to certain therapeutic drugs. Moreover, genetic and epigenetic alterations in the MMR system demonstrate a significant relationship with human fertility and related treatments, which helps us to understand the etiology and susceptibility of human infertility. Alterations in the MMR system may also influence the health of offspring conceived by assisted reproductive technology in humans. However, further studies are needed to explore the specific mechanisms by which the MMR system may affect human infertility. This review addresses the physiological mechanisms of the MMR system and associations between alterations of the MMR system and human fertility and related treatments, and potential effects on the next generation.

  12. Regulation of Arabidopsis root development by nitrate availability.

    Science.gov (United States)

    Zhang, H; Forde, B G

    2000-01-01

    When the root systems of many plant species are exposed to a localized source of nitrate (NO3- they respond by proliferating their lateral roots to colonize the nutrient-rich zone. This study reviews recent work with Arabidopsis thaliana in which molecular genetic approaches are being used to try to understand the physiological and genetic basis for this response. These studies have led to the conclusion that there are two distinct pathways by which NO3- modulates root branching in Arabidopsis. On the one hand, meristematic activity in lateral root tips is stimulated by direct contact with an enriched source of NO3- (the localized stimulatory effect). On the other, a critical stage in the development of the lateral root (just after its emergence from the primary root) is highly susceptible to inhibition by a systemic signal that is related to the amount of NO3- absorbed by the plant (the systemic inhibitory effect). Evidence has been obtained that the localized stimulatory effect is a direct effect of the NO3- ion itself rather than a nutritional effect. A NO3(-)-inducible MADS-box gene (ANR1) has been identified which encodes a component of the signal transduction pathway linking the external NO3- supply to the increased rate of lateral root elongation. Experiments using auxin-resistant mutants have provided evidence for an overlap between the auxin and NO3- response pathways in the control of lateral root elongation. The systemic inhibitory effect, which does not affect lateral root initiation but delays the activation of the lateral root meristem, appears to be positively correlated with the N status of the plant and is postulated to involve a phloem-mediated signal from the shoot.

  13. A review of the influence of root-associating fungi and root exudates on the success of invasive plants

    Directory of Open Access Journals (Sweden)

    Cindy Bongard

    2012-08-01

    Full Text Available Plant-fungal interactions are essential for understanding the distribution and abundance of plants species. Recently, arbuscular mycorrhizal fungal (AMF partners of non-indigenous invasive plants have been hypothesized to be a critical factor influencing the invasion processes. AMF are known to improve nutrient and moisture uptake, as well as disrupt parasitic and pathogenic microbes in the host plant. Such benefits may enable invaders to establish significant and persistent populations in environments previously dominated by natives. Coupling these findings with studies on invader pathogen-disrupting root exudates is not well documented in the literature describing plant invasion strategies. The interaction effects of altered AMF associations and the impact of invader root exudates would be more relevant than understanding the AMF dynamics or the phytochemistry of successful invaders in isolation, particularly given that AMF and root exudates can have a similar role in pathogen control but function quite differently. One means to achieve this goal is to assess these strategies concurrently by characterizing both the general (mostly pathogens or commensals and AM-specific fungal colonization patterns found in field collected root samples of successful invaders, native plants growing within dense patches of invaders, and native plants growing separately from invaders. In this review I examine the emerging evidence of the ways in which AMF-plant interactions and the production of defensive root exudates provide pathways to invasive plant establishment and expansion, and conclude that interaction studies must be pursued to achieve a more comprehensive understanding of successful plant invasion.

  14. Root exudates from grafted-root watermelon showed a certain contribution in inhibiting Fusarium oxysporum f. sp. niveum.

    Directory of Open Access Journals (Sweden)

    Ning Ling

    Full Text Available Grafting watermelon onto bottle gourd rootstock is commonly used method to generate resistance to Fusarium oxysporum f. sp. niveum (FON, but knowledge of the effect of the root exudates of grafted watermelon on this soil-borne pathogen in rhizosphere remains limited. To investigate the root exudate profiles of the own-root bottle gourd, grafted-root watermelon and own-root watermelon, recirculating hydroponic culture system was developed to continuously trap these root exudates. Both conidial germination and growth of FON were significantly decreased in the presence of root exudates from the grafted-root watermelon compared with the own-root watermelon. HPLC analysis revealed that the composition of the root exudates released by the grafted-root watermelon differed not only from the own-root watermelon but also from the bottle gourd rootstock plants. We identified salicylic acid in all 3 root exudates, chlorogenic acid and caffeic acid in root exudates from own-root bottle gourd and grafted-root watermelon but not own-root watermelon, and abundant cinnamic acid only in own-root watermelon root exudates. The chlorogenic and caffeic acid were candidates for potentiating the enhanced resistance of the grafted watermelon to FON, therefore we tested the effects of the two compounds on the conidial germination and growth of FON. Both phenolic acids inhibited FON conidial germination and growth in a dose-dependent manner, and FON was much more susceptible to chlorogenic acid than to caffeic acid. In conclusion, the key factor in attaining the resistance to Fusarium wilt is grafting on the non-host root stock, however, the root exudates profile also showed some contribution in inhibiting FON. These results will help to better clarify the disease resistance mechanisms of grafted-root watermelon based on plant-microbe communication and will guide the improvement of strategies against Fusarium-mediated wilt of watermelon plants.

  15. Characterization of mature maize (Zea mays L.) root system architecture and complexity in a diverse set of Ex-PVP inbreds and hybrids.

    Science.gov (United States)

    Hauck, Andrew L; Novais, Joana; Grift, Tony E; Bohn, Martin O

    2015-01-01

    The mature root system is a vital plant organ, which is critical to plant performance. Commercial maize (Zea mays L.) breeding has resulted in a steady increase in plant performance over time, along with noticeable changes in above ground vegetative traits, but the corresponding changes in the root system are not presently known. In this study, roughly 2500 core root systems from field trials of a set of 10 diverse elite inbreds formerly protected by Plant Variety Protection plus B73 and Mo17 and the 66 diallel intercrosses among them were evaluated for root traits using high throughput image-based phenotyping. Overall root architecture was modeled by root angle (RA) and stem diameter (SD), while root complexity, the amount of root branching, was quantified using fractal analysis to obtain values for fractal dimension (FD) and fractal abundance (FA). For each trait, per se line effects were highly significant and the most important contributor to trait performance. Mid-parent heterosis and specific combining ability was also highly significant for FD, FA, and RA, while none of the traits showed significant general combining ability. The interaction between the environment and the additive line effect was also significant for all traits. Within the inbred and hybrid generations, FD and FA were highly correlated (rp ≥ 0.74), SD was moderately correlated to FD and FA (0.69 ≥ rp ≥ 0.48), while the correlation between RA and other traits was low (0.13 ≥ rp ≥ -0.40). Inbreds with contrasting effects on complexity and architecture traits were observed, suggesting that root complexity and architecture traits are inherited independently. A more comprehensive understanding of the maize root system and the way it interacts with the environment will be useful for defining adaptation to nutrient acquisition and tolerance to stress from drought and high plant densities, critical factors in the yield gains of modern hybrids.

  16. Root rots

    Science.gov (United States)

    Kathryn Robbins; Philip M. Wargo

    1989-01-01

    Root rots of central hardwoods are diseases caused by fungi that infect and decay woody roots and sometimes also invade the butt portion of the tree. By killing and decaying roots, root rotting fungi reduce growth, decrease tree vigor, and cause windthrow and death. The most common root diseases of central hardwoods are Armillaria root rot, lnonotus root rot, and...

  17. Fertilizer application and root development analyzed by neutron imaging

    International Nuclear Information System (INIS)

    Nihei, Naoto; Tanoi, Keitaro; Nakanishi, Tomoko M.

    2013-01-01

    We studied the development of the soybean root system under different application of fertilizer applying neutron imaging technique. When neutron beam was irradiated, the root image as well as fertilizer imbedded in a thin aluminum container was clearly projected, since water amount in roots are higher than that in soil. Through image analysis, the development of root system was studied under different application of the fertilizer. The development of a main root with lateral roots was observed without applying fertilizer. When the fertilizer was homogeneously supplied to the soil, the morphological development of the root showed the similar pattern to that grown without fertilizer, in different to the amount of the fertilizer. In the case of local application of the fertilizer, lateral position or downward to the main root, the inhibition of the root growth was observed, suggesting that the localization of the fertilizer is responsible for reduction of the soybean yield. (author)

  18. Optimizing root system architecture in biofuel crops for sustainable energy production and soil carbon sequestration.

    Science.gov (United States)

    To, Jennifer Pc; Zhu, Jinming; Benfey, Philip N; Elich, Tedd

    2010-09-08

    Root system architecture (RSA) describes the dynamic spatial configuration of different types and ages of roots in a plant, which allows adaptation to different environments. Modifications in RSA enhance agronomic traits in crops and have been implicated in soil organic carbon content. Together, these fundamental properties of RSA contribute to the net carbon balance and overall sustainability of biofuels. In this article, we will review recent data supporting carbon sequestration by biofuel crops, highlight current progress in studying RSA, and discuss future opportunities for optimizing RSA for biofuel production and soil carbon sequestration.

  19. X-Ray Computed Tomography Reveals the Response of Root System Architecture to Soil Texture1[OPEN

    Science.gov (United States)

    Rogers, Eric D.; Monaenkova, Daria; Mijar, Medhavinee; Goldman, Daniel I.

    2016-01-01

    Root system architecture (RSA) impacts plant fitness and crop yield by facilitating efficient nutrient and water uptake from the soil. A better understanding of the effects of soil on RSA could improve crop productivity by matching roots to their soil environment. We used x-ray computed tomography to perform a detailed three-dimensional quantification of changes in rice (Oryza sativa) RSA in response to the physical properties of a granular substrate. We characterized the RSA of eight rice cultivars in five different growth substrates and determined that RSA is the result of interactions between genotype and growth environment. We identified cultivar-specific changes in RSA in response to changing growth substrate texture. The cultivar Azucena exhibited low RSA plasticity in all growth substrates, whereas cultivar Bala root depth was a function of soil hardness. Our imaging techniques provide a framework to study RSA in different growth environments, the results of which can be used to improve root traits with agronomic potential. PMID:27208237

  20. Effects of aluminum on nucleoli in root tip cells and selected physiological and biochemical characters in Allium cepa var. agrogarum L.

    Science.gov (United States)

    Qin, Rong; Jiao, Yunqiu; Zhang, Shanshan; Jiang, Wusheng; Liu, Donghua

    2010-10-21

    Increased Al concentration causes reduction of mitotic activity, induction of nucleolar alteration, increase of the production of ROS and alteration of several antioxidant enzyme activities in plant cells. Allium cepa is an excellent plant and a useful biomarker for environmental monitoring. Limited information is available about the effects of Al on nucleoli, antioxidant enzyme system, contents of MDA and soluble protein in A. cepa. Therefore, we carried out the investigation in order to better understand the effects of Al on the growth, nucleoli in root tip cells and selected physiological and biochemical characters. The results showed that the root growth exposed to 50 μM Al was inhibited significantly. 50 μM Al could induce some particles of argyrophilic proteins scattered in the nuclei and extruded from the nucleoli into the cytoplasm. The nucleolus did not disaggregate normally and still remained its characteristic structure during metaphase. Nucleolar reconstruction was inhibited. 50 μM Al induced high activities of SOD and POD in leaves and roots significantly (P nucleoli and the alterations of antioxidant enzyme activities, MDA and soluble protein contents in Allium cepa can serve as useful biomarkers, which can provide valuable information for monitoring and forecasting effects of exposure to Al in real scenarios conditions. Among the antioxidant enzymes SOD and POD appear to play a key role in the antioxidant defense mechanism under Al toxicity condition. Data from MDA concentration show that Al indirectly produces superoxide radicals, resulting in increased lipid peroxidative products and oxidative stress.

  1. 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

  2. Novel MtCEP1 peptides produced in vivo differentially regulate root development in Medicago truncatula.

    Science.gov (United States)

    Mohd-Radzman, Nadiatul A; Binos, Steve; Truong, Thy T; Imin, Nijat; Mariani, Michael; Djordjevic, Michael A

    2015-08-01

    Small, post-translationally modified and secreted peptides regulate diverse plant developmental processes. Due to low natural abundance, it is difficult to isolate and identify these peptides. Using an improved peptide isolation protocol and Orbitrap mass spectrometry, nine 15-amino-acid CEP peptides were identified that corresponded to the two domains encoded by Medicago truncatula CEP1 (MtCEP1). Novel arabinosylated and hydroxylated peptides were identified in root cultures overexpressing MtCEP1. The five most abundant CEP peptides were hydroxylated and these species were detected also in low amounts in vector control samples. Synthetic peptides with different hydroxylation patterns differentially affected root development. Notably, the domain 1 peptide hydroxylated at Pro4 and Pro11 (D1:HyP4,11) imparted the strongest inhibition of lateral root emergence when grown with 5mM KNO3 and stimulated the highest increase in nodule number when grown with 0mM KNO3. Inhibition of lateral root emergence by D1:HyP4,11 was not alleviated by removing peptide exposure. In contrast, the domain 2 peptide hydroxylated at Pro11 (D2:HyP11) increased stage III-IV lateral root primordium numbers by 6-fold (P emerge. Auxin addition at levels which stimulated lateral root formation in wild-type plants had little or no ameliorating effect on CEP peptide-mediated inhibition of lateral root formation or emergence. Both peptides increased and altered the root staining pattern of the auxin-responsive reporter GH3:GUS suggesting CEPs alter auxin sensitivity or distribution. The results showed that CEP primary sequence and post-translational modifications influence peptide activities and the improved isolation procedure effectively and reproducibly identifies and characterises CEPs. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  3. Fungi in neotropical epiphyte roots.

    Science.gov (United States)

    Bermudes, D; Benzing, D H

    1989-01-01

    Roots of thirty-eight Ecuadoran vascular epiphytes, representing eleven angiosperm families, were examined for the presence of symbiotic microorganisms. Most orchid roots contained fungal endophytes like those that regularly infect terrestrial counterparts. Hyphae were also common in and on nonorchid roots, but assignments of these relationships to known mycorrhizal morphologies was not possible in all cases. Evidence of vesicular-arbuscular mycorrhizae (VAM) existed in a number of subjects while in Ericaceae and Campanulaceae a fungal association similar to the demateaceous surface fungi (DSF) described for alpine and prarie plants was usually present. Some associations were characterized by multicellular propagules on root surfaces. The significance of these findings and the factors likely to influence occurrence and consequences of root-fungus mutualisms in tropical forest canopies are discussed. Facts and considerations that could aid future inquiry on these systems are provided.

  4. 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.

  5. Exogenous nitrate induces root branching and inhibits primary root growth in Capsicum chinense Jacq.

    Science.gov (United States)

    Celis-Arámburo, Teresita de Jesús; Carrillo-Pech, Mildred; Castro-Concha, Lizbeth A; Miranda-Ham, María de Lourdes; Martínez-Estévez, Manuel; Echevarría-Machado, Ileana

    2011-12-01

    The effects of nitrate (NO₃⁻) on the root system are complex and depend on several factors, such as the concentration available to the plant, endogenous nitrogen status and the sensitivity of the species. Though these effects have been widely documented on Arabidopsis and cereals, no reports are available in the Capsicum genus. In this paper, we have determined the effect of an exogenous in vitro application of this nutrient on root growth in habanero pepper (Capsicum chinense Jacq.). Exposure to NO₃⁻ inhibited primary root growth in both, dose- and time-dependent manners. The highest inhibition was attained with 0.1 mM NO₃⁻ between the fourth and fifth days of treatment. Inhibition of primary root growth was observed by exposing the root to both homogeneous and heterogeneous conditions of the nutrient; in contrast, ammonium was not able to induce similar changes. NO₃⁻-induced inhibition of primary root growth was reversed by treating the roots with IAA or NPA, a polar auxin transport inhibitor. Heterogeneous NO₃⁻ application stimulated the formation and elongation of lateral roots in the segment where the nutrient was present, and this response was influenced by exogenous phytohormones. These results demonstrate that habanero pepper responds to NO₃⁻ in a similar fashion to other species with certain particular differences. Therefore, studies in this model could help to elucidate the mechanisms by which roots respond to NO₃⁻ in fluctuating soil environments. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  6. One-visit endodontic retreatment of combined external/internal root resorption using a calcium-enriched mixture.

    Science.gov (United States)

    Asgary, Saeed; Ahmadyar, Maryam

    2012-01-01

    Combined external and internal root resorption (ERR/IRR) is a rare endodontic disease that leads to alteration of the root canal anatomy. This report describes the management of an endodontically failed molar that was severely affected by ERR/IRR. Radiographic examination demonstrated inadequate obturation of the root canals associated with ERR/IRR and a large periradicular lesion. During nonsurgical endodontic retreatment, the root canals were subjected to conventional chemomechanical debridement. In the same session, the entire distal root canal was obturated using a calcium-enriched mixture (CEM) cement, and the mesial canals were obturated with gutta-percha/sealer. The clinical findings and follow-up radiographs indicated favorable treatment outcomes after 12 months. One-visit application of CEM cement could be a successful approach for the management of combined ERR/IRR.

  7. Rhizobial infection in Adesmia bicolor (Fabaceae) roots.

    Science.gov (United States)

    Bianco, Luciana

    2014-09-01

    The native legume Adesmia bicolor shows nitrogen fixation efficiency via symbiosis with soil rhizobia. The infection mechanism by means of which rhizobia infect their roots has not been fully elucidated to date. Therefore, the purpose of the present study was to identify the infection mechanism in Adesmia bicolor roots. To this end, inoculated roots were processed following conventional methods as part of our root anatomy study, and the shape and distribution of root nodules were analyzed as well. Neither root hairs nor infection threads were observed in the root system, whereas infection sites-later forming nodules-were observed in the longitudinal sections. Nodules were found to form between the main root and the lateral roots. It can be concluded that in Adesmia bicolor, a bacterial crack entry infection mechanism prevails and that such mechanism could be an adaptive strategy of this species which is typical of arid environments.

  8. Adult root structure of Mediterranean shrubs: relationship with post-fire regenerative syndrome.

    Science.gov (United States)

    Saura-Mas, S; Lloret, F

    2014-01-01

    Life-history attributes can impose differences on root system structures and properties related to nutrient and water uptake. Here, we assess whether plants with different post-fire regenerative strategies (resprouters, seeders and seeder-resprouters) differ in the topological and morphological properties of their root systems (external path, altitude, magnitude, topological index, specific root length, root length, root-to-shoot biomass ratio, length of the main axis of the root system and link length). To achieve these objectives, we sampled individuals from eight woody species in a shrubland located in the western Mediterranean Basin. We sampled the adult root systems using manual field excavation with the aid of an air compressor. The results indicate that resprouters have a higher root-to-shoot ratio, confirming their higher ability to store water, starch and nutrients and to invest in the belowground biomass. Moreover, this pattern would allow them to explore deeper parts of the soil layers. Seeder species would benefit from a higher specific root length, pointing to increased relative root growth and water uptake rates. This study confirms that seeders and resprouters may differ in nutrient and water uptake ability according to the characteristics of their root system. Species that can both resprout and establish seedlings after fire had different patterns of root system structure; in particular, root:shoot ratio was more similar to resprouters and specific root length was closer to seeders, supporting the distinct functional performance of this type of species. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  9. Early Effects of Altered Gravity Environments on Plant Cell Growth and Cell Proliferation: Characterization of Morphofunctional Nucleolar Types in an Arabidopsis Cell Culture System

    Energy Technology Data Exchange (ETDEWEB)

    Manzano, Ana I.; Herranz, Raúl; Manzano, Aránzazu [Centro de Investigaciones Biológicas (CSIC), Madrid (Spain); Loon, Jack J. W. A. van [Department of Oral and Maxillofacial Surgery/Oral Pathology, Dutch Experiment Support Center, VU University Medical Center, Amsterdam (Netherlands); Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam (Netherlands); ESA-ESTEC, TEC-MMG, Noordwijk (Netherlands); Medina, F. Javier, E-mail: fjmedina@cib.csic.es [Centro de Investigaciones Biológicas (CSIC), Madrid (Spain)

    2016-02-05

    Changes in the cell growth rate of an in vitro cellular system in Arabidopsis thaliana induced by short exposure to an altered gravity environment have been estimated by a novel approach. The method consisted of defining three structural nucleolar types which are easy and reliable indicators of the ribosome biogenesis activity and, consequently, of protein biosynthesis, a parameter strictly correlated to cell growth in this cellular system. The relative abundance of each nucleolar type was statistically assessed in different conditions of gravity. Samples exposed to simulated microgravity for 200 min showed a significant decrease in nucleolar activity compared to 1g controls, whereas samples exposed to hypergravity (2g) for the same period showed nucleolar activity slightly increased. These effects could be considered as an early cellular response to the environmental alteration, given the short duration of the treatment. The functional significance of the structural data was validated by a combination of several different well-known parameters, using microscopical, flow cytometry, qPCR, and proteomic approaches, which showed that the decreased cell growth rate was decoupled from an increased cell proliferation rate under simulated microgravity, and the opposite trend was observed under hypergravity. Actually, not all parameters tested showed the same quantitative changes, indicating that the response to the environmental alteration is time-dependent. These results are in agreement with previous observations in root meristematic cells and they show the ability of plant cells to produce a response to gravity changes, independently of their integration into plant organs.

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

    OpenAIRE

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

    2014-01-01

    Development and activity of plant roots exhibits high adaptive variability. Although it is well-documented, that physicochemical soil properties can strongly influence root morphology and root exudation, particularly under field conditions, a comparative assessment is complicated by the impact of additional factors, such as climate and cropping history. To overcome these limitations, in this study, field soils originating from an unique experimental plot system with three different soil types...

  11. Roots bridge water to nutrients: a study of utilizing hydraulic redistribution through root systems to extract nutrients in the dry soils

    Science.gov (United States)

    Yan, J.; Ghezzehei, T. A.

    2017-12-01

    The rhizosphere is the region of soil that surrounds by individual plant roots. While its small volume and narrow region compared to bulk soil, the rhizosphere regulates numerous processes that determine physical structure, nutrient distribution, and biodiversity of soils. One of the most important and distinct functions of the rhizosphere is the capacity of roots to bridge and redistribute soil water from wet soil layers to drier layers. This process was identified and defined as hydraulic lift or hydraulic redistribution, a passive process driven by gradients in water potentials and it has attracted much research attention due to its important role in global water circulation and agriculture security. However, while previous studies mostly focused on the hydrological or physiological impacts of hydraulic redistribution, limited research has been conducted to elucidate its role in nutrient cycling and uptake. In this study, we aim to test the possibility of utilizing hydraulic redistribution to facilitate the nutrient movement and uptake from resource segregated zone. Our overarching hypothesis is that plants can extract nutrients from the drier but nutrient-rich regions by supplying sufficient amounts of water from the wet but nutrient-deficient regions. To test our hypothesis, we designed split-root systems of tomatoes with unequal supply of water and nutrients in different root compartments. More specifically, we transplanted tomato seedlings into sand or soil mediums, and grew them under conditions with alternate 12-h lightness and darkness. We continuously monitored the temperature, water and nutrient content of soils in these separated compartments. The above and below ground biomass were also quantified to evaluate the impacts on the plant growth. The results were compared to a control with evenly supply of water and nutrients to assess the plant growth, nutrient leaching and uptake without hydraulic redistribution.

  12. Influence of microgravity on cellular differentiation in root caps of Zea mays

    Science.gov (United States)

    Moore, R.; Fondren, W. M.; McClelen, C. E.; Wang, C. L.

    1987-01-01

    We launched imbibed seeds of Zea mays into outer space aboard the space shuttle Columbia to determine the influence of microgravity on cellular differentiation in root caps. The influence of microgravity varied with different stages of cellular differentiation. Overall, microgravity tended to 1) increase relative volumes of hyaloplasm and lipid bodies, 2) decrease the relative volumes of plastids, mitochondria, dictyosomes, and the vacuome, and 3) exert no influence on the relative volume of nuclei in cells comprising the root cap. The reduced allocation of dictyosomal volume in peripheral cells of flight-grown seedlings correlated positively with their secretion of significantly less mucilage than peripheral cells of Earth-grown seedlings. These results indicate that 1) microgravity alters the patterns of cellular differentiation and structures of all cell types comprising the root cap, and 2) the influence of microgravity on cellular differentiation in root caps of Zea mays is organelle specific.

  13. Do ectomycorrhizal and arbuscular mycorrhizal temperate tree species systematically differ in root order-related fine root morphology and biomass?

    OpenAIRE

    Kubisch, Petra; Hertel, Dietrich; Leuschner, Christoph

    2015-01-01

    While most temperate broad-leaved tree species form ectomycorrhizal (EM) symbioses, a few species have arbuscular mycorrhizas (AM). It is not known whether EM and AM tree species differ systematically with respect to fine root morphology, fine root system size and root functioning. In a species-rich temperate mixed forest, we studied the fine root morphology and biomass of three EM and three AM tree species from the genera Acer, Carpinus, Fagus, Fraxinus, and Tilia searching for principal dif...

  14. Root production, distribution, and turnover in conventional and organic northern highbush blueberry systems

    Science.gov (United States)

    Northern highbush blueberry (Vaccinium corymbosum L.) is a shallow-rooted crop with very fine, fibrous roots. Recently, we installed minirhizotrons (root observation tubes) in a conventional and an organic blueberry planting in western Oregon. We wanted to know exactly when and where new roots were ...

  15. A comparison of three rotary systems and hand instrumentation technique for the elimination of Enterococcus faecalis from the root canal.

    Science.gov (United States)

    Gorduysus, Melahat; Nagas, Emre; Torun, Ozgur Yildirim; Gorduysus, Omer

    2011-12-01

    The aim of this study was to compare the in vitro reduction of a bacterial population in a root canal by mechanical instrumentation using three rotary systems and hand instrumentation technique. The root canals contaminated with a suspension of Enterococcus faecalis were instrumented using ProTaper, K3, HeroShaper and K-file hand instrumentation technique. Later the root canals were sampled. After serial dilutions, samples were incubated in culture media for 24 h. Bacterial colonies were counted and the results were given as number of colony-forming units per millilitre. The results showed that all the canal instrumentation systems reduced the number of bacterial cells in the root canals. Statistically, ProTaper instruments were more effective in reducing the number of bacteria than the other rotary files or hand instruments. © 2010 The Authors. Australian Endodontic Journal © 2010 Australian Society of Endodontology.

  16. 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.

  17. Mycorrhization helper bacteria: a case of specificity for altering ectomycorrhiza architecture but not ectomycorrhiza formation.

    Science.gov (United States)

    Aspray, Thomas J; Frey-Klett, Pascale; Jones, Julie E; Whipps, John M; Garbaye, Jean; Bending, Gary D

    2006-11-01

    Mycorrhization helper bacteria (MHB), isolated from phylogenetically distinct ectomycorrhizal symbioses involving Lactarius rufus, Laccaria bicolor or Suillus luteus, were tested for fungus specificity to enhance L. rufus-Pinus sylvestris or L. bicolor-P. sylvestris mycorrhiza formation. As MHB isolated from the L. rufus and S. luteus mycorrhiza were originally characterised using a microcosm system, we assessed their ability to enhance mycorrhiza formation in a glasshouse system in order to determine the extent to which MHB are system-specific. Paenibacillus sp. EJP73, an MHB for L. rufus in the microcosm, significantly enhanced L. bicolor mycorrhiza formation in the glasshouse, demonstrating that the MHB effect of this bacterium is neither fungus-specific nor limited to the original experimental system. Although the five MHB strains studied were unable to significantly enhance L. rufus mycorrhiza formation, two of them did have a significant effect on dichotomous short root branching by L. rufus. The effect was specific to Paenibacillus sp. EJP73 and Burkholderia sp. EJP67, the two strains isolated from L. rufus mycorrhiza, and was not associated with auxin production. Altered mycorrhiza architecture rather than absolute number of mycorrhizal roots may be an important previously overlooked parameter for defining MHB effects.

  18. Contributions of roots and rootstocks to sustainable, intensified crop production.

    Science.gov (United States)

    Gregory, Peter J; Atkinson, Christopher J; Bengough, A Glyn; Else, Mark A; Fernández-Fernández, Felicidad; Harrison, Richard J; Schmidt, Sonja

    2013-03-01

    Sustainable intensification is seen as the main route for meeting the world's increasing demands for food and fibre. As demands mount for greater efficiency in the use of resources to achieve this goal, so the focus on roots and rootstocks and their role in acquiring water and nutrients, and overcoming pests and pathogens, is increasing. The purpose of this review is to explore some of the ways in which understanding root systems and their interactions with soils could contribute to the development of more sustainable systems of intensive production. Physical interactions with soil particles limit root growth if soils are dense, but root-soil contact is essential for optimal growth and uptake of water and nutrients. X-ray microtomography demonstrated that maize roots elongated more rapidly with increasing root-soil contact, as long as mechanical impedance was not limiting root elongation, while lupin was less sensitive to changes in root-soil contact. In addition to selecting for root architecture and rhizosphere properties, the growth of many plants in cultivated systems is profoundly affected by selection of an appropriate rootstock. Several mechanisms for scion control by rootstocks have been suggested, but the causal signals are still uncertain and may differ between crop species. Linkage map locations for quantitative trait loci for disease resistance and other traits of interest in rootstock breeding are becoming available. Designing root systems and rootstocks for specific environments is becoming a feasible target.

  19. 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

  20. Computed tomography evaluation of rotary systems on the root canal transportation and centering ability

    Directory of Open Access Journals (Sweden)

    André PAGLIOSA

    2015-01-01

    Full Text Available Abstract : The endodontic preparation of curved and narrow root canals is challenging, with a tendency for the prepared canal to deviate away from its natural axis. The aim of this study was to evaluate, by cone-beam computed tomography, the transportation and centering ability of curved mesiobuccal canals in maxillary molars after biomechanical preparation with different nickel-titanium (NiTi rotary systems. Forty teeth with angles of curvature ranging from 20° to 40° and radii between 5.0 mm and 10.0 mm were selected and assigned into four groups (n = 10, according to the biomechanical preparative system used: Hero 642 (HR, Liberator (LB, ProTaper (PT, and Twisted File (TF. The specimens were inserted into an acrylic device and scanned with computed tomography prior to, and following, instrumentation at 3, 6 and 9 mm from the root apex. The canal degree of transportation and centering ability were calculated and analyzed using one-way ANOVA and Tukey’s tests (α = 0.05. The results demonstrated no significant difference (p > 0.05 in shaping ability among the rotary systems. The mean canal transportation was: -0.049 ± 0.083 mm (HR; -0.004 ± 0.044 mm (LB; -0.003 ± 0.064 mm (PT; -0.021 ± 0.064 mm (TF. The mean canal centering ability was: -0.093 ± 0.147 mm (HR; -0.001 ± 0.100 mm (LB; -0.002 ± 0.134 mm (PT; -0.033 ± 0.133 mm (TF. Also, there was no significant difference among the root segments (p > 0.05. It was concluded that the Hero 642, Liberator, ProTaper, and Twisted File rotary systems could be safely used in curved canal instrumentation, resulting in satisfactory preservation of the original canal shape.

  1. Computed tomography evaluation of rotary systems on the root canal transportation and centering ability

    International Nuclear Information System (INIS)

    Pagliosa, Andre; Raucci-Neto, Walter; Silva-Souza, Yara Teresinha Correa; Alfredo, Edson; Sousa-Neto, Manoel Damiao; Versiani, Marco Aurelio

    2015-01-01

    The endodontic preparation of curved and narrow root canals is challenging, with a tendency for the prepared canal to deviate away from its natural axis. The aim of this study was to evaluate, by cone-beam computed tomography, the transportation and centering ability of curved mesiobuccal canals in maxillary molars after biomechanical preparation with different nickel-titanium (NiTi) rotary systems. Forty teeth with angles of curvature ranging from 20° to 40° and radii between 5.0 mm and 10.0 mm were selected and assigned into four groups (n = 10), according to the biomechanical preparative system used: Hero 642 (HR), Liberator (LB), ProTaper (PT), and Twisted File (TF). The specimens were inserted into an acrylic device and scanned with computed tomography prior to, and following, instrumentation at 3, 6 and 9 mm from the root apex. The canal degree of transportation and centering ability were calculated and analyzed using one-way ANOVA and Tukey’s tests (α = 0.05). The results demonstrated no significant difference (p > 0.05) in shaping ability among the rotary systems. The mean canal transportation was: -0.049 ± 0.083 mm (HR); -0.004 ± 0.044 mm (LB); -0.003 ± 0.064 mm (PT); -0.021 ± 0.064 mm (TF). The mean canal centering ability was: -0.093 ± 0.147 mm (HR); -0.001 ± 0.100 mm (LB); -0.002 ± 0.134 mm (PT); -0.033 ± 0.133 mm (TF). Also, there was no significant difference among the root segments (p > 0.05). It was concluded that the Hero 642, Liberator, ProTaper, and Twisted File rotary systems could be safely used in curved canal instrumentation, resulting in satisfactory preservation of the original canal shape. (author)

  2. Computed tomography evaluation of rotary systems on the root canal transportation and centering ability

    Energy Technology Data Exchange (ETDEWEB)

    Pagliosa, Andre; Raucci-Neto, Walter; Silva-Souza, Yara Teresinha Correa; Alfredo, Edson, E-mail: ysousa@unaerp.br [Universidade de Ribeirao Preto (UNAERP), SP (Brazil). Fac. de Odontologia; Sousa-Neto, Manoel Damiao; Versiani, Marco Aurelio [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Fac. de Odoentologia

    2015-03-01

    The endodontic preparation of curved and narrow root canals is challenging, with a tendency for the prepared canal to deviate away from its natural axis. The aim of this study was to evaluate, by cone-beam computed tomography, the transportation and centering ability of curved mesiobuccal canals in maxillary molars after biomechanical preparation with different nickel-titanium (NiTi) rotary systems. Forty teeth with angles of curvature ranging from 20° to 40° and radii between 5.0 mm and 10.0 mm were selected and assigned into four groups (n = 10), according to the biomechanical preparative system used: Hero 642 (HR), Liberator (LB), ProTaper (PT), and Twisted File (TF). The specimens were inserted into an acrylic device and scanned with computed tomography prior to, and following, instrumentation at 3, 6 and 9 mm from the root apex. The canal degree of transportation and centering ability were calculated and analyzed using one-way ANOVA and Tukey’s tests (α = 0.05). The results demonstrated no significant difference (p > 0.05) in shaping ability among the rotary systems. The mean canal transportation was: -0.049 ± 0.083 mm (HR); -0.004 ± 0.044 mm (LB); -0.003 ± 0.064 mm (PT); -0.021 ± 0.064 mm (TF). The mean canal centering ability was: -0.093 ± 0.147 mm (HR); -0.001 ± 0.100 mm (LB); -0.002 ± 0.134 mm (PT); -0.033 ± 0.133 mm (TF). Also, there was no significant difference among the root segments (p > 0.05). It was concluded that the Hero 642, Liberator, ProTaper, and Twisted File rotary systems could be safely used in curved canal instrumentation, resulting in satisfactory preservation of the original canal shape. (author)

  3. Can diversity in root architecture explain plant water use efficiency? A modeling study.

    Science.gov (United States)

    Tron, Stefania; Bodner, Gernot; Laio, Francesco; Ridolfi, Luca; Leitner, Daniel

    2015-09-24

    Drought stress is a dominant constraint to crop production. Breeding crops with adapted root systems for effective uptake of water represents a novel strategy to increase crop drought resistance. Due to complex interaction between root traits and high diversity of hydrological conditions, modeling provides important information for trait based selection. In this work we use a root architecture model combined with a soil-hydrological model to analyze whether there is a root system ideotype of general adaptation to drought or water uptake efficiency of root systems is a function of specific hydrological conditions. This was done by modeling transpiration of 48 root architectures in 16 drought scenarios with distinct soil textures, rainfall distributions, and initial soil moisture availability. We find that the efficiency in water uptake of root architecture is strictly dependent on the hydrological scenario. Even dense and deep root systems are not superior in water uptake under all hydrological scenarios. Our results demonstrate that mere architectural description is insufficient to find root systems of optimum functionality. We find that in environments with sufficient rainfall before the growing season, root depth represents the key trait for the exploration of stored water, especially in fine soils. Root density, instead, especially near the soil surface, becomes the most relevant trait for exploiting soil moisture when plant water supply is mainly provided by rainfall events during the root system development. We therefore concluded that trait based root breeding has to consider root systems with specific adaptation to the hydrology of the target environment.

  4. Synchronous high-resolution phenotyping of leaf and root growth in Nicotiana tabacum over 24-h periods with GROWMAP-plant

    Directory of Open Access Journals (Sweden)

    Ruts Tom

    2013-01-01

    Full Text Available Abstract Background Root growth is highly responsive to temporal changes in the environment. On the contrary, diel (24 h leaf expansion in dicot plants is governed by endogenous control and therefore its temporal pattern does not strictly follow diel changes in the environment. Nevertheless, root and shoot are connected with each other through resource partitioning and changing environments for one organ could affect growth of the other organ, and hence overall plant growth. Results We developed a new technique, GROWMAP-plant, to monitor growth processes synchronously in leaf and root of the same plant with a high resolution over the diel period. This allowed us to quantify treatment effects on the growth rates of the treated and non-treated organ and the possible interaction between them. We subjected the root system of Nicotiana tabacum seedlings to three different conditions: constant darkness at 22°C (control, constant darkness at 10°C (root cooling, and 12 h/12 h light–dark cycles at 22°C (root illumination. In all treatments the shoot was kept under the same 12 h/12 h light–dark cycles at 22°C. Root growth rates were found to be constant when the root-zone environment was kept constant, although the root cooling treatment significantly reduced root growth. Root velocity was decreased after light-on and light-off events of the root illumination treatment, resulting in diel root growth rhythmicity. Despite these changes in root growth, leaf growth was not affected substantially by the root-zone treatments, persistently showing up to three times higher nocturnal growth than diurnal growth. Conclusion GROWMAP-plant allows detailed synchronous growth phenotyping of leaf and root in the same plant. Root growth was very responsive to the root cooling and root illumination, while these treatments altered neither relative growth rate nor diel growth pattern in the seedling leaf. Our results that were obtained simultaneously in growing

  5. Ex Vivo Comparison of Mtwo and RaCe Rotary File Systems in Root Canal Deviation: One File Only versus the Conventional Method.

    Science.gov (United States)

    Aminsobhani, Mohsen; Razmi, Hasan; Nozari, Solmaz

    2015-07-01

    Cleaning and shaping of the root canal system is an important step in endodontic therapy. New instruments incorporate new preparation techniques that can improve the efficacy of cleaning and shaping. The aim of this study was to compare the efficacy of Mtwo and RaCe rotary file systems in straightening the canal curvature using only one file or the conventional method. Sixty mesial roots of extracted human mandibular molars were prepared by RaCe and Mtwo nickel-titanium (NiTi) rotary files using the conventional and only one rotary file methods. The working length was 18 mm and the curvatures of the root canals were between 15-45°. By superimposing x-ray images before and after the instrumentation, deviation of the canals was assessed using Adobe Photoshop CS3 software. Preparation time was recorded. Data were analyzed using three-way ANOVA and Tukey's post hoc test. There were no significant differences between RaCe and Mtwo or between the two root canal preparation methods in root canal deviation in buccolingual and mesiodistal radiographs (P>0.05). Changes of root canal curvature in >35° subgroups were significantly more than in other subgroups with smaller canal curvatures. Preparation time was shorter in one file only technique. According to the results, the two rotary systems and the two root canal preparation methods had equal efficacy in straightening the canals; but the preparation time was shorter in one file only group.

  6. Systemic and local regulation of phosphate and nitrogen transporter genes by arbuscular mycorrhizal fungi in roots of winter wheat (Triticum aestivum L.).

    Science.gov (United States)

    Duan, Jianfeng; Tian, Hui; Drijber, Rhae A; Gao, Yajun

    2015-11-01

    Previous studies have reported that the expression of phosphate (Pi) or nitrogen (N) transporter genes in roots of plants could be regulated by arbuscular mycorrhizal (AM) fungi, but little is known whether the regulation is systemic or not. The present study investigated the systemic and local regulation of multiple phosphate and nitrogen transporter genes by four AM fungal species belonging to four genera in the roots of winter wheat. A split-root culture system with AM inoculated (MR) and non-inoculated root compartments (NR) was used to investigate the systemic or local responses of phosphate and nitrogen transporter genes to colonization by four AM fungi in the roots of wheat. The expression of four Pi transporter, five nitrate transporter, and three ammonium transporter genes was quantified using real-time PCR. Of the four AM fungi tested, all locally increased expression of the AM-inducible Pi transporter genes, and most locally decreased expression of a Pi-starvation inducible Pi transporter gene. The addition of N in soil increased the expression of either Pi starvation inducible Pi transporters or AM inducible Pi transporters. Inoculation with AM fungi either had no effect, or could locally or systemically down-regulate expression of nitrogen transporter genes depending on gene type and AM fungal species. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  7. Development of test method for evaluating root resistance of pavement used for roof garden caused by thickening growth of root

    Energy Technology Data Exchange (ETDEWEB)

    Ishihara, Saori; Tanaka, Kyoji [Tokyo Institute of Technology, Tokyo, (Japan)

    2010-07-01

    The growth of roots of plants can damage roof garden components, such as pavements. This paper developed a test method for evaluating the resistance of pavement used in roof gardens to damage from a thickening growth of roots. The study assessed the behaviour of plant roots and evaluated the force of root growth subjected to hypertrophy. A system to measure the enlargement force of roots was designed and used for measurements over a period of 8 months on a cherry blossom of 21 years growth. The enlargement force was approximately 440 N/cm. A mechanical simulated root was designed and used to carry out experimental tests on asphalt pavements. The tests results demonstrated the viability of simulated root for evaluation of root resistances in pavements and various components of roof gardens.

  8. Extracting Metrics for Three-dimensional Root Systems: Volume and Surface Analysis from In-soil X-ray Computed Tomography Data.

    Science.gov (United States)

    Suresh, Niraj; Stephens, Sean A; Adams, Lexor; Beck, Anthon N; McKinney, Adriana L; Varga, Tamas

    2016-04-26

    Plant roots play a critical role in plant-soil-microbe interactions that occur in the rhizosphere, as well as processes with important implications to climate change and crop management. Quantitative size information on roots in their native environment is invaluable for studying root growth and environmental processes involving plants. X-ray computed tomography (XCT) has been demonstrated to be an effective tool for in situ root scanning and analysis. We aimed to develop a costless and efficient tool that approximates the surface and volume of the root regardless of its shape from three-dimensional (3D) tomography data. The root structure of a Prairie dropseed (Sporobolus heterolepis) specimen was imaged using XCT. The root was reconstructed, and the primary root structure was extracted from the data using a combination of licensed and open-source software. An isosurface polygonal mesh was then created for ease of analysis. We have developed the standalone application imeshJ, generated in MATLAB(1), to calculate root volume and surface area from the mesh. The outputs of imeshJ are surface area (in mm(2)) and the volume (in mm(3)). The process, utilizing a unique combination of tools from imaging to quantitative root analysis, is described. A combination of XCT and open-source software proved to be a powerful combination to noninvasively image plant root samples, segment root data, and extract quantitative information from the 3D data. This methodology of processing 3D data should be applicable to other material/sample systems where there is connectivity between components of similar X-ray attenuation and difficulties arise with segmentation.

  9. Carbon contributions from roots in cotton based rotations

    Science.gov (United States)

    Tan, D. K. Y.; Hulugalle, N. R.

    2012-04-01

    Most research on the decline in soil organic carbon (SOC) stocks in Australian cotton farming systems has focussed on the inputs from above-ground crop residues, with contribution from roots being less studied. This paper aims to outline the contribution of cotton roots and roots of other crops to soil carbon stocks in furrow-irrigated Vertisols in several cotton (Gossypium hirsutum L.)-based rotations. Data was collected from cotton-based rotation systems: cotton monoculture, cotton-vetch (Vicia benghalensis) Roth.), cotton-wheat (Triticum aestivum L.), cotton-wheat-vetch, cotton-corn, corn-corn, cotton-sorghum (Sorghum bicolor L.) and from BollgardTM II (Bt) and non-Bt cotton. Land management systems were permanent beds, with or without standing stubble, and conventional tillage. Root growth in the surface 0.10 m was measured with the core-break method, and that in the 0.10 to 1.0 m depth with a minirhizotron and I-CAP image capture system. These measurements were used to derive root C added to soil through intra-seasonal root death (Clost), C in roots remaining at the end of season (Croot), and total root C added to soil (Ctotal = Croot + Clost). Ctotal in non-Bt cotton (Sicot 80RRF, 0.9 t C/ha/year) was higher than in Bt cotton (Sicot 80RRF, 0.6 t C/ha/year). Overall, Ctotal from cotton roots ranges between 0.5 to 5 t C/ha/year, with Clost contributing 25-70%. Ctotal was greater with vetch than with wheat and was in the order of vetch in cotton-wheat-vetch (5.1 t C/ha/year) > vetch in cotton-vetch (1.9 t C/ha/year) > wheat in cotton-wheat (1.6 t C/ha/year) = wheat in cotton-wheat-vetch (1.7 t C/ha/year). Intra-seasonal root mortality accounted for 12% of total root carbon in vetch and 36% in wheat. Average corn Ctotal with monoculture was 9.3 t/ha and with cotton-corn 5.0 t/ha. Ctotal averaged between both treatments was, thus, of the order of 7.7 t C/ha/year and average Clost 0.04 t/ha/yr. Sorghum roots contributed less carbon with conventional tillage (8.2 t

  10. C-shaped root canal in a maxillary first molar: a case report.

    Science.gov (United States)

    Yilmaz, Z; Tuncel, B; Serper, A; Calt, S

    2006-02-01

    This case report presents an unusual C-shaped root canal system in a maxillary first molar tooth. Although C-shaped root canals are most frequently seen in the mandibular second molar, they may also appear in maxillary molars. A literature search revealed only a few case reports of C-shaped root canal systems in maxillary molars. The present case describes a C-shaped canal in the buccal root of a maxillary first molar. The endodontic access cavity displayed two canal orifices, one leading to the canal system in the buccal root, the other into the palatal root canal system. In the buccal root, what appeared to be the mesial and distal canals joined to form a single C-shaped canal. --Careful examination of radiographs and the internal anatomy of teeth is essential.-- The location and morphology of root canals should be identified at high magnification under the microscope.

  11. Calcium activity of upper thoracic dorsal root ganglion neurons in zucker diabetic Fatty rats

    DEFF Research Database (Denmark)

    Ghorbani, Marie Louise; Nyborg, Niels C B; Fjalland, Bjarne

    2013-01-01

    The aim of the present study was to examine the calcium activity of C8-T5 dorsal root ganglion (DRG) neurons from Zucker diabetic fatty rats. In total, 8 diabetic ZDF fatty animals and 8 age-matched control ZDF lean rats were employed in the study. C8-T5 dorsal root ganglia were isolated bilatera......The aim of the present study was to examine the calcium activity of C8-T5 dorsal root ganglion (DRG) neurons from Zucker diabetic fatty rats. In total, 8 diabetic ZDF fatty animals and 8 age-matched control ZDF lean rats were employed in the study. C8-T5 dorsal root ganglia were isolated...... in calcium activity of the DRG neurons were found, potentially indicating altered neuronal responses during myocardial ischemia....

  12. Mechanical touch responses of Arabidopsis TCH1-3 mutant roots on inclined hard-agar surface

    Science.gov (United States)

    Zha, Guodong; Wang, Bochu; Liu, Junyu; Yan, Jie; Zhu, Liqing; Yang, Xingyan

    2016-01-01

    The gravity-induced mechanical touch stimulus can affect plant root architecture. Mechanical touch responses of plant roots are an important aspect of plant root growth and development. Previous studies have reported that Arabidopsis TCH1-3 genes are involved in mechano-related events, how-ever, the physiological functions of TCH1-3 genes in Arabidopsis root mechanoresponses remain unclear. In the present study, we applied an inclined hard agar plate method to produce mechanical touch stimulus, and provided evidence that altered mechanical environment could influence root growth. Furthermore, tch1-3 Arabidopsis mutants were investigated on inclined agar surfaces to explore the functions of TCH1-3 genes on Arabidopsis root mechanoresponses. The results showed that two tch2 mutants, cml24-2 and cml24-4, exhibited significantly reduced root length, biased skewing, and decreased density of lateral root. In addition, primary root length and density of lateral root of tch3 (cml12-2) was significantly decreased on inclined agar surfaces. This study indicates that the tch2 and tch3 mutants are hypersensitive to mechanical touch stimulus, and TCH2 (CML24-2 and CML24-4) and TCH3 (CML12-2) genes may participate in the mechanical touch response of Arabidopsis roots.

  13. Long-Term Effects of Season of Prescribed Burn on the Fine-Root Growth, Root Carbohydrates, and Foliar Dynamics of Mature Longleaf Pine

    Science.gov (United States)

    Eric A. Kuehler; Mary Anne Sword Sayer; James D. Haywood; C. Dan Andries

    2004-01-01

    Depending on the season and intensity of fire, as well as the phenology of foliage and new root growth, fire may damage foliage, and subsequently decrease whole-crown carbon fixation and allocation to the root system. In central Louisiana the authors investigated how season of prescribed burning affects fine-root dynamics, root carbohydrate relations, and leaf area...

  14. Proteomic and metabolomic analyses of soybean root tips under flooding stress.

    Science.gov (United States)

    Komatsu, Setsuko; Nakamura, Takuji; Sugimoto, Yurie; Sakamoto, Kazunori

    2014-01-01

    Flooding is one of the serious problems for soybean plants because it inhibits growth. Proteomic and metabolomic techniques were used to determine whether proteins and metabolites are altered in the root tips of soybeans under flooding stress. Two-day-old soybean plants were flooded for 2 days, and proteins and metabolites were extracted from root tips. Flooding-responsive proteins were identified using two-dimensional- or SDS-polyacrylamide gel electrophoresis- based proteomics techniques. Using both techniques, 172 proteins increased and 105 proteins decreased in abundance in the root tips of flood-stressed soybean. The abundance of methionine synthase, heat shock cognate protein, urease, and phosphoenol pyruvate carboxylase was significantly increased by flooding stress. Furthermore, 73 flooding-responsive metabolites were identified using capillary electrophoresis-mass spectrometry. The levels of gamma-aminobutyric acid, glycine, NADH2, and phosphoenol pyruvate were increased by flooding stress. Taken together, these results suggest that synthesis of phosphoenol pyruvate by way of oxaloacetate produced in the tricarboxylic acid cycle is activated in soybean root tips in response to flooding stress, and that flooding stress also leads to modulation of the urea cycle in the root tips.

  15. Disentangling the intertwined genetic bases of root and shoot growth in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Marie Bouteillé

    Full Text Available Root growth and architecture are major components of plant nutrient and water use efficiencies and these traits are the matter of extensive genetic analysis in several crop species. Because root growth relies on exported assimilate from the shoot, and changes in assimilate supply are known to alter root architecture, we hypothesized (i that the genetic bases of root growth could be intertwined with the genetic bases of shoot growth and (ii that the link could be either positive, with alleles favouring shoot growth also favouring root growth, or negative, because of competition for assimilates. We tested these hypotheses using a quantitative genetics approach in the model species Arabidopsis thaliana and the Bay-0 × Shahdara recombinant inbred lines population. In accordance with our hypothesis, root and shoot growth traits were strongly correlated and most root growth quantitative trait loci (QTLs colocalized with shoot growth QTLs with positive alleles originating from either the same or the opposite parent. In order to identify regions that could be responsible for root growth independently of the shoot, we generated new variables either based on root to shoot ratios, residuals of root to shoot correlations or coordinates of principal component analysis. These variables showed high heritability allowing genetic analysis. They essentially all yielded similar results pointing towards two regions involved in the root--shoot balance. Using Heterogeneous Inbred Families (a kind of near-isogenic lines, we validated part of the QTLs present in these two regions for different traits. Our study thus highlights the difficulty of disentangling intertwined genetic bases of root and shoot growth and shows that this difficulty can be overcome by using simple statistical tools.

  16. The effect of modifying rooting depths and nitrification inhibitors on nutrient uptake from organic biogas residues in maize

    Science.gov (United States)

    Dietrich, Charlotte C.; Koller, Robert; Nagel, Kerstin A.; Schickling, Anke; Schrey, Silvia D.; Jablonowski, Nicolai D.

    2017-04-01

    shallower layers, where their effect on plant growth was temporarily most pronounced. At final harvest (21 DAS) however, effects of nitrification inhibitors on plant height were visible only in deeper layers. Furthermore, the statistically significant interaction between the factors time x layer depths x nitrification inhibitors underlined the dynamic influence of nitrification inhibitors on plant growth over time and across rooting depths. This study offers insights into optimizing nutrient uptake and plant productivity by (re-) using residues from the biogas industry. It is among the first to monitor and try to explain the dynamics of nitrification inhibitors on root system architecture over time. A modified N-fertilization application scheme might also serve as a promising tool in optimizing phytoremediation and phytomining techniques through predictably altering root structure in fertilized layers. References: Nagel, K. A. ; Putz, A. ; Gilmer, F. ; Heinz, K. ; Fischbach, A. ; Pfeifer, J. ; Faget, M. ; Blossfeld, S. ; Ernst, M. ; Dimaki, C. ; Kastenholz, B. ; Kleinert, A.-K. ; Galinski, A. ; Scharr, H. ; Fiorani, F. ; Schurr, U. (2012): GROWSCREEN-Rhizo is a novel phenotyping robot enabling simultaneous measurements of root and shoot growth for plants grown in soil-filled rhizotrons.
Functional plant biology 39(11), 891-904.

  17. Root-Knot and Cyst Nematodes Activate Procambium-Associated Genes in Arabidopsis Roots

    Directory of Open Access Journals (Sweden)

    Yasuka L. Yamaguchi

    2017-07-01

    Full Text Available Developmental plasticity is one of the most striking features of plant morphogenesis, as plants are able to vary their shapes in response to environmental cues. Biotic or abiotic stimuli often promote organogenesis events in plants not observed under normal growth conditions. Root-knot nematodes (RKNs are known to parasitize multiple species of rooting plants and to induce characteristic tissue expansion called galls or root-knots on the roots of their hosts by perturbing the plant cellular machinery. Galls contain giant cells (GCs and neighboring cells, and the GCs are a source of nutrients for the parasitizing nematode. Highly active cell proliferation was observed in galls. However, the underlying mechanisms that regulate the symptoms triggered by the plant-nematode interaction have not yet been elucidated. In this study, we deciphered the molecular mechanism of gall formation with an in vitro infection assay system using RKN Meloidogyne incognita, and the model plant Arabidopsis thaliana. By taking advantages of this system, we performed next-generation sequencing-based transcriptome profiling, and found that the expression of procambium identity-associated genes were enriched during gall formation. Clustering analyses with artificial xylogenic systems, together with the results of expression analyses of the candidate genes, showed a significant correlation between the induction of gall cells and procambium-associated cells. Furthermore, the promoters of several procambial marker genes such as ATHB8, TDR and WOX4 were activated not only in M. incognita-induced galls, but similarly in M. javanica induced-galls and Heterodera schachtii-induced syncytia. Our findings suggest that phytoparasitic nematodes modulate the host’s developmental regulation of the vascular stem cells during gall formation.

  18. Root-Knot and Cyst Nematodes Activate Procambium-Associated Genes in Arabidopsis Roots.

    Science.gov (United States)

    Yamaguchi, Yasuka L; Suzuki, Reira; Cabrera, Javier; Nakagami, Satoru; Sagara, Tomomi; Ejima, Chika; Sano, Ryosuke; Aoki, Yuichi; Olmo, Rocio; Kurata, Tetsuya; Obayashi, Takeshi; Demura, Taku; Ishida, Takashi; Escobar, Carolina; Sawa, Shinichiro

    2017-01-01

    Developmental plasticity is one of the most striking features of plant morphogenesis, as plants are able to vary their shapes in response to environmental cues. Biotic or abiotic stimuli often promote organogenesis events in plants not observed under normal growth conditions. Root-knot nematodes (RKNs) are known to parasitize multiple species of rooting plants and to induce characteristic tissue expansion called galls or root-knots on the roots of their hosts by perturbing the plant cellular machinery. Galls contain giant cells (GCs) and neighboring cells, and the GCs are a source of nutrients for the parasitizing nematode. Highly active cell proliferation was observed in galls. However, the underlying mechanisms that regulate the symptoms triggered by the plant-nematode interaction have not yet been elucidated. In this study, we deciphered the molecular mechanism of gall formation with an in vitro infection assay system using RKN Meloidogyne incognita , and the model plant Arabidopsis thaliana. By taking advantages of this system, we performed next-generation sequencing-based transcriptome profiling, and found that the expression of procambium identity-associated genes were enriched during gall formation. Clustering analyses with artificial xylogenic systems, together with the results of expression analyses of the candidate genes, showed a significant correlation between the induction of gall cells and procambium-associated cells. Furthermore, the promoters of several procambial marker genes such as ATHB8 , TDR and WOX4 were activated not only in M. incognita -induced galls, but similarly in M. javanica induced-galls and Heterodera schachtii -induced syncytia. Our findings suggest that phytoparasitic nematodes modulate the host's developmental regulation of the vascular stem cells during gall formation.

  19. Optimizing the chemical aspect of root canal irrigation

    NARCIS (Netherlands)

    de Macedo, R.G.

    2013-01-01

    Root canal treatment is aimed at the removal of inflamed and infected tissue present in the root canal system. It will prevent the entrance of new microorganisms or nutrients in order to maintain or create a healthy environment around the root. There is sufficient evidence that shows that

  20. Transcriptomic profiling of Bacillus amyloliquefaciens FZB42 in response to maize root exudates

    LENUS (Irish Health Repository)

    Fan, Ben

    2012-06-21

    AbstractBackgroundPlant root exudates have been shown to play an important role in mediating interactions between plant growth-promoting rhizobacteria (PGPR) and their host plants. Most investigations were performed on Gram-negative rhizobacteria, while much less is known about Gram-positive rhizobacteria. To elucidate early responses of PGPR to root exudates, we investigated changes in the transcriptome of a Gram-positive PGPR to plant root exudates.ResultsBacillus amyloliquefaciens FZB42 is a well-studied Gram-positive PGPR. To obtain a comprehensive overview of FZB42 gene expression in response to maize root exudates, microarray experiments were performed. A total of 302 genes representing 8.2% of the FZB42 transcriptome showed significantly altered expression levels in the presence of root exudates. The majority of the genes (261) was up-regulated after incubation of FZB42 with root exudates, whereas only 41 genes were down-regulated. Several groups of the genes which were strongly induced by the root exudates are involved in metabolic pathways relating to nutrient utilization, bacterial chemotaxis and motility, and non-ribosomal synthesis of antimicrobial peptides and polyketides.ConclusionsHere we present a transcriptome analysis of the root-colonizing bacterium Bacillus amyloliquefaciens FZB42 in response to maize root exudates. The 302 genes identified as being differentially transcribed are proposed to be involved in interactions of Gram-positive bacteria with plants.

  1. High-resolution synchrotron imaging shows that root hairs influence rhizosphere soil structure formation.

    Science.gov (United States)

    Koebernick, Nicolai; Daly, Keith R; Keyes, Samuel D; George, Timothy S; Brown, Lawrie K; Raffan, Annette; Cooper, Laura J; Naveed, Muhammad; Bengough, Anthony G; Sinclair, Ian; Hallett, Paul D; Roose, Tiina

    2017-10-01

    In this paper, we provide direct evidence of the importance of root hairs on pore structure development at the root-soil interface during the early stage of crop establishment. This was achieved by use of high-resolution (c. 5 μm) synchrotron radiation computed tomography (SRCT) to visualise both the structure of root hairs and the soil pore structure in plant-soil microcosms. Two contrasting genotypes of barley (Hordeum vulgare), with and without root hairs, were grown for 8 d in microcosms packed with sandy loam soil at 1.2 g cm -3 dry bulk density. Root hairs were visualised within air-filled pore spaces, but not in the fine-textured soil regions. We found that the genotype with root hairs significantly altered the porosity and connectivity of the detectable pore space (> 5 μm) in the rhizosphere, as compared with the no-hair mutants. Both genotypes showed decreasing pore space between 0.8 and 0.1 mm from the root surface. Interestingly the root-hair-bearing genotype had a significantly greater soil pore volume-fraction at the root-soil interface. Effects of pore structure on diffusion and permeability were estimated to be functionally insignificant under saturated conditions when simulated using image-based modelling. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  2. Role of altered coagulation-fibrinolytic system in the pathophysiology of diabetic retinopathy.

    Science.gov (United States)

    Behl, Tapan; Velpandian, Thirumurthy; Kotwani, Anita

    2017-05-01

    The implications of altered coagulation-fibrinolytic system in the pathophysiology of several vascular disorders, such as stroke and myocardial infarction, have been well researched upon and established. However, its role in the progression of diabetic retinopathy has not been explored much. Since a decade, it is known that hyperglycemia is associated with a hypercoagulated state and the various impairments it causes are well acknowledged as independent risk factors for the development of cardiovascular diseases. But recent studies suggest that the hypercoagulative state and diminished fibrinolytic responses might also