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Sample records for leaf roll virus

  1. Characterization of R genes involved in resistance to Cherry leaf roll virus in paradox hybrids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A single dominant ‘R’ gene (clrvR), in black walnuts (Juglans hindsii) or ‘paradox’ hybrids (J. hindsii x J. regia) confers resistance to Cherry leaf roll virus (CLRV), the causal agent of blackline disease. The identification and cloning of the ‘R’ gene is expected to aid the walnut breeding progra...

  2. 40 CFR 174.513 - Potato Leaf Roll Virus Resistance Gene (also known as orf1/orf2 gene); exemption from the...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Potato Leaf Roll Virus Resistance Gene... Virus Resistance Gene (also known as orf1/orf2 gene); exemption from the requirement of a tolerance. An... protectant Potato Leaf Roll Virus Resistance Gene (also known as orf1/orf2 gene) in or on all...

  3. 40 CFR 174.513 - Potato Leaf Roll Virus Resistance Gene (also known as orf1/orf2 gene); exemption from the...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Potato Leaf Roll Virus Resistance Gene... Virus Resistance Gene (also known as orf1/orf2 gene); exemption from the requirement of a tolerance. An... protectant Potato Leaf Roll Virus Resistance Gene (also known as orf1/orf2 gene) in or on all...

  4. Host Species-Dependent Population Structure of a Pollen-Borne Plant Virus, Cherry Leaf Roll Virus

    PubMed Central

    Rebenstorf, Kathrin; Candresse, Thierry; Dulucq, Marie Josée; Büttner, Carmen; Obermeier, Christian

    2006-01-01

    Cherry leaf roll virus (CLRV) belongs to the Nepovirus genus within the family Comoviridae. It has a host range which includes a number of wild tree and shrub species. The serological and molecular diversity of CLRV was assessed using a collection of isolates and samples recovered from woody and herbaceous host plants from different geographical origins. Molecular diversity was assessed by sequencing a short (375-bp) region of the 3′ noncoding region (NCR) of the genomic RNAs while serological diversity was assessed using a panel of seven monoclonal antibodies raised initially against a walnut isolate of CLRV. The genomic region analyzed was shown to exhibit a significant degree of molecular variability with an average pairwise divergence of 8.5% (nucleotide identity). Similarly, serological variability proved to be high, with no single monoclonal antibody being able to recognize all isolates analyzed. Serological and molecular phylogenetic reconstructions showed a strong correlation. Remarkably, the diversity of CLRV populations is to a large extent defined by the host plant from which the viral samples are originally obtained. There are relatively few reports of plant viruses for which the genetic diversity is structured by the host plant. In the case of CLRV, we hypothesize that this situation may reflect the exclusive mode of transmission in natural plant populations by pollen and by seeds. These modes of transmission are likely to impose barriers to host change by the virus, leading to rapid biological and genetic separation of CLRV variants coevolving with different plant host species. PMID:16474152

  5. 40 CFR 174.513 - Potato Leaf Roll Virus Resistance Gene (also known as orf1/orf2 gene); exemption from the...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Potato Leaf Roll Virus Resistance Gene (also known as orf1/orf2 gene); exemption from the requirement of a tolerance. 174.513 Section 174.513... Virus Resistance Gene (also known as orf1/orf2 gene); exemption from the requirement of a tolerance....

  6. 40 CFR 174.513 - Potato Leaf Roll Virus Resistance Gene (also known as orf1/orf2 gene); exemption from the...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Potato Leaf Roll Virus Resistance Gene (also known as orf1/orf2 gene); exemption from the requirement of a tolerance. 174.513 Section 174.513... Virus Resistance Gene (also known as orf1/orf2 gene); exemption from the requirement of a tolerance....

  7. 40 CFR 174.513 - Potato Leaf Roll Virus Resistance Gene (also known as orf1/orf2 gene); exemption from the...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Potato Leaf Roll Virus Resistance Gene (also known as orf1/orf2 gene); exemption from the requirement of a tolerance. 174.513 Section 174.513... Virus Resistance Gene (also known as orf1/orf2 gene); exemption from the requirement of a tolerance....

  8. Transgenic resistance in potato plants expressing potato leaf roll virus (PLRV) replicase gene sequences is RNA-mediated and suggests the involvement of post-transcriptional gene silencing.

    PubMed

    Vazquez Rovere, C; Asurmendi, S; Hopp, H E

    2001-07-01

    Genetically engineered expression of replicase encoding sequences has been proposed as an efficient system to confer protection against virus diseases by eliciting protection mechanisms in the plant. Potato leaf-roll was one of the first diseases for which this kind of protection was engineered in potato plants. However, details of the protecting mechanism were not reported, so far. The ORF2b of an Argentinean strain of PLRV was cloned and sequenced finding 94% and 97% of homology with Australian and Dutch strains, respectively. To elucidate the mechanism of protection against PLRV infection, three versions of ORF2b (non-translatable sense, translatable sense with an engineered ATG and antisense) were constructed under the control of the 35S CaMV promoter and the nos terminator and introduced in potato plants (cv. Kennebec) by Agrobacterium tumefaciens-mediated transformation. Grafting infection experiments showed that resistant transgenic plants could be obtained with any of the constructs, suggesting that the mechanism of protection is independent of the expression of protein and is RNA mediated. Field trial infection confirmed that resistant transgenic events were obtained. Biolistic transient transformation experiments of leaves derived from transgenic plants using a gene coding for the fusion protein GUS-ORF2b, followed by scoring of the number of GUS expressing leaf spots, supported that the protection is mediated by a post-transcriptional gene silencing mechanism.

  9. The silver lining of a viral agent: increasing seed yield and harvest index in Arabidopsis by ectopic expression of the potato leaf roll virus movement protein.

    PubMed

    Kronberg, Kristin; Vogel, Florian; Rutten, Twan; Hajirezaei, Mohammed-Reza; Sonnewald, Uwe; Hofius, Daniel

    2007-11-01

    Ectopic expression of viral movement proteins (MPs) has previously been shown to alter plasmodesmata (PD) function and carbon partitioning in transgenic plants, giving rise to the view of PD being dynamic and highly regulated structures that allow resource allocation to be adapted to environmental and developmental needs. However, most work has been restricted to solanaceous species and the potential use of MP expression to improve biomass and yield parameters has not been addressed in detail. Here we demonstrate that MP-mediated modification of PD function can substantially alter assimilate allocation, biomass production, and reproductive growth in Arabidopsis (Arabidopsis thaliana). These effects were achieved by constitutive expression of the potato leaf roll virus 17-kD MP (MP17) fused to green fluorescent protein (GFP) in different Arabidopsis ecotypes. The resulting transgenic plants were analyzed for PD localization of the MP17:GFP fusion protein and different lines with low to high expression levels were selected for further analysis. Low-level accumulation of MP17 resulted in enhanced sucrose efflux from source leaves and a considerably increased vegetative biomass production. In contrast, high MP17 levels impaired sucrose export, resulting in source leaf-specific carbohydrate accumulation and a strongly reduced vegetative growth. Surprisingly, later during development the MP17-mediated inhibition of resource allocation was reversed, and final seed yield increased in average up to 30% in different transgenic lines as compared to wild-type plants. This resulted in a strongly improved harvest index. The release of the assimilate export block was paralleled by a reduced PD binding of MP17 in senescing leaves, indicating major structural changes of PD during leaf senescence.

  10. Semi-Rolled Leaf2 modulates rice leaf rolling by regulating abaxial side cell differentiation

    PubMed Central

    Liu, Xiaofei; Li, Ming; Liu, Kai; Tang, Ding; Sun, Mingfa; Li, Yafei; Shen, Yi; Du, Guijie; Cheng, Zhukuan

    2016-01-01

    Moderate leaf rolling maintains the erectness of leaves and minimizes the shadowing between leaves which is helpful to establish ideal plant architecture. Here, we describe a srl2 (semi-rolled leaf2) rice mutant, which has incurved leaves due to the presence of defective sclerenchymatous cells on the abaxial side of the leaf and displays narrow leaves and reduced plant height. Map-based cloning revealed that SRL2 encodes a novel plant-specific protein of unknown biochemical function. SRL2 was mainly expressed in the vascular bundles of leaf blades, leaf sheaths, and roots, especially in their sclerenchymatous cells. The transcriptional activities of several leaf development-related YABBY genes were significantly altered in the srl2 mutant. Double mutant analysis suggested that SRL2 and SHALLOT-LIKE1 (SLL1)/ROLLED LEAF9 (RL9) function in distinct pathways that regulate abaxial-side leaf development. Hence, SRL2 plays an important role in regulating leaf development, particularly during sclerenchymatous cell differentiation. PMID:26873975

  11. Semi-Rolled Leaf2 modulates rice leaf rolling by regulating abaxial side cell differentiation.

    PubMed

    Liu, Xiaofei; Li, Ming; Liu, Kai; Tang, Ding; Sun, Mingfa; Li, Yafei; Shen, Yi; Du, Guijie; Cheng, Zhukuan

    2016-04-01

    Moderate leaf rolling maintains the erectness of leaves and minimizes the shadowing between leaves which is helpful to establish ideal plant architecture. Here, we describe asrl2(semi-rolled leaf2) rice mutant, which has incurved leaves due to the presence of defective sclerenchymatous cells on the abaxial side of the leaf and displays narrow leaves and reduced plant height. Map-based cloning revealed that SRL2 encodes a novel plant-specific protein of unknown biochemical function.SRL2 was mainly expressed in the vascular bundles of leaf blades, leaf sheaths, and roots, especially in their sclerenchymatous cells. The transcriptional activities of several leaf development-related YABBY genes were significantly altered in the srl2 mutant. Double mutant analysis suggested that SRL2 and SHALLOT-LIKE1(SLL1)/ROLLED LEAF9(RL9) function in distinct pathways that regulate abaxial-side leaf development. Hence, SRL2 plays an important role in regulating leaf development, particularly during sclerenchymatous cell differentiation.

  12. First report of seed-borne cherry leaf roll virus in wild potato, Solanum acaule, from South America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A virus, designated JCM-79, was isolated from wild potato (Solanum acaule Bitt.) plants grown from true seed received at USDA-APHIS Potato Quarantine Program from Peru. JCM-79 was mechanically transmissible to Nicotiana clevelandii, N.tabacum cv. Samsun NN, and Chenopodium quinoa. Symptoms in the ...

  13. Development of molecular resistance in potato against potato leaf roll virus and potato virus Y through Agrobacterium-mediated double transgenesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato leafroll virus (PLRV) and potato virus Y (PVY) are the two major viral problems for the potato production all over the world. Transgenic approaches involving the expression of viral genes are being developed to provide protection for plants against viral diseases. The purpose of this study w...

  14. SHALLOT-LIKE1 is a KANADI transcription factor that modulates rice leaf rolling by regulating leaf abaxial cell development.

    PubMed

    Zhang, Guang-Heng; Xu, Qian; Zhu, Xu-Dong; Qian, Qian; Xue, Hong-Wei

    2009-03-01

    As an important agronomic trait, rice (Oryza sativa L.) leaf rolling has attracted much attention from plant biologists and breeders. Moderate leaf rolling increases the photosynthesis of cultivars and hence raises grain yield. However, the relevant molecular mechanism remains unclear. Here, we show the isolation and functional characterization of SHALLOT-LIKE1 (SLL1), a key gene controlling rice leaf rolling. sll1 mutant plants have extremely incurved leaves due to the defective development of sclerenchymatous cells on the abaxial side. Defective development can be functionally rescued by expression of SLL1. SLL1 is transcribed in various tissues and accumulates in the abaxial epidermis throughout leaf development. SLL1 encodes a SHAQKYF class MYB family transcription factor belonging to the KANADI family. SLL1 deficiency leads to defective programmed cell death of abaxial mesophyll cells and suppresses the development of abaxial features. By contrast, enhanced SLL1 expression stimulates phloem development on the abaxial side and suppresses bulliform cell and sclerenchyma development on the adaxial side. Additionally, SLL1 deficiency results in increased chlorophyll and photosynthesis. Our findings identify the role of SLL1 in the modulation of leaf abaxial cell development and in sustaining abaxial characteristics during leaf development. These results should facilitate attempts to use molecular breeding to increase the photosynthetic capacity of rice, as well as other crops, by modulating leaf development and rolling.

  15. Complete genome sequence of bean leaf crumple virus, a novel begomovirus infecting common bean in Colombia.

    PubMed

    Carvajal-Yepes, Monica; Zambrano, Leidy; Bueno, Juan M; Raatz, Bodo; Cuellar, Wilmer J

    2017-02-10

    A copy of the complete genome of a novel bipartite begomovirus infecting common bean (Phaseolus vulgaris L.) in Colombia was obtained by rolling-circle amplification (RCA), cloned, and sequenced. The virus is associated with leaf crumple symptoms and significant yield losses in Andean and Mesoamerican beans. Such symptoms have been reported increasingly in Colombia since at least 2002, and we detected the virus in leaf material collected since 2008. Sequence analysis showed that the virus is a member of a distinct species, sharing 81% and 76% nucleotide (nt) sequence identity (in DNA-A and DNA-B, respectively) to other begomoviruses infecting common bean in the Americas. The data obtained support the taxonomic status of this virus (putatively named 'bean leaf crumple virus', BLCrV) as a member of a novel species in the genus Begomovirus.

  16. Replicative intermediates of maize streak virus found during leaf development.

    PubMed

    Erdmann, Julia B; Shepherd, Dionne N; Martin, Darren P; Varsani, Arvind; Rybicki, Edward P; Jeske, Holger

    2010-04-01

    Geminiviruses of the genera Begomovirus and Curtovirus utilize three replication modes: complementary-strand replication (CSR), rolling-circle replication (RCR) and recombination-dependent replication (RDR). Using two-dimensional gel electrophoresis, we now show for the first time that maize streak virus (MSV), the type member of the most divergent geminivirus genus, Mastrevirus, does the same. Although mastreviruses have fewer regulatory genes than other geminiviruses and uniquely express their replication-associated protein (Rep) from a spliced transcript, the replicative intermediates of CSR, RCR and RDR could be detected unequivocally within infected maize tissues. All replicative intermediates accumulated early and, to varying degrees, were already present in the shoot apex and leaves at different maturation stages. Relative to other replicative intermediates, those associated with RCR increased in prevalence during leaf maturation. Interestingly, in addition to RCR-associated DNA forms seen in other geminiviruses, MSV also apparently uses dimeric open circular DNA as a template for RCR.

  17. Stachytarpheta leaf curl virus is a novel monopartite begomovirus species.

    PubMed

    Xiong, Q; Fan, S; Guo, X; Zhou, X

    2005-11-01

    Begomovirus isolates were obtained from Stachytarpheta jamaicensis plants showing leaf curl and chlorosis symptoms collected in the Hainan province of China. The complete sequences of isolates Hn5-4, Hn6-1, Hn30 and Hn34 were determined to be 2748, 2751, 2748 and 2748 nucleotides long, respectively. The complete sequences of the four isolates share more than 94.9% nucleotide sequence identity, but all of them have less than 86% nucleotide sequence identity with other reported begomoviruses. The molecular data show that Hn5-4, Hn6-1, Hn30 and Hn34 are isolates of a distinct begomovirus species, for which the name Stachytarpheta leaf curl virus (StaLCV) is proposed. PCR and Southern blot analyses demonstrate that all the collected field samples are not associated with DNAbeta or DNA-B components. An infectious clone of StaLCV isolate Hn5-4 was constructed, and could efficiently infect Nicotiana benthamiana, N. tabacum Samsun, N. glutinosa, Lycopersicon esculentum and Petunia hybrida plants, inducing upward leaf roll and vein swelling symptoms. In addition, we illustrate that StaLCV can functionally interact with distinct DNAbeta molecules in plants.

  18. Characterization of Rolled and Erect Leaf 1 in regulating leave morphology in rice

    PubMed Central

    Chen, Qiaoling; Xie, Qingjun; Gao, Ju; Wang, Wenyi; Sun, Bo; Liu, Bohan; Zhu, Haitao; Peng, Haifeng; Zhao, Haibing; Liu, Changhong; Wang, Jiang; Zhang, Jingliu; Zhang, Guiquan; Zhang, Zemin

    2015-01-01

    Leaf morphology, particularly in crop, is one of the most important agronomic traits because it influences the yield through the manipulation of photosynthetic capacity and transpiration. To understand the regulatory mechanism of leaf morphogenesis, an Oryza sativa dominant mutant, rolled and erect leaf 1 (rel1) has been characterized. This mutant has a predominant rolled leaf, increased leaf angle, and reduced plant height phenotype that results in a reduction in grain yield. Electron microscope observations indicated that the leaf incurvations of rel1 dominant mutants result from the alteration of the size and number of bulliform cells. Molecular cloning revealed that the rel1 dominant mutant phenotype is caused by the activation of the REL1 gene, which encodes a novel unknown protein, despite its high degree of conservation among monocot plants. Moreover, the downregulation of the REL1 gene in the rel1 dominant mutant restored the phenotype of this dominant mutant. Alternatively, overexpression of REL1 in wild-type plants induced a phenotype similar to that of the dominant rel1 mutant, indicating that REL1 plays a positive role in leaf rolling and bending. Consistent with the observed rel1 phenotype, the REL1 gene was predominantly expressed in the meristem of various tissues during plant growth and development. Nevertheless, the responsiveness of both rel1 dominant mutants and REL1-overexpressing plants to exogenous brassinosteroid (BR) was reduced. Moreover, transcript levels of BR response genes in the rel1 dominant mutants and REL1-overexpressing lines were significantly altered. Additionally, seven REL1-interacting proteins were also identified from a yeast two-hybrid screen. Taken together, these findings suggest that REL1 regulates leaf morphology, particularly in leaf rolling and bending, through the coordination of BR signalling transduction. PMID:26142419

  19. Whitefly transmission of the Sweet potato leaf curl virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sweetpotato whitefly, Bemisia tabaci (Gennadius) is highly adaptive and polyphagous on taxonomically diverse species of plants on a global scale. This whitefly transmits numerous plant viruses, including Begomoviruses (Geminiviridae). We recently found the Sweet Potato Leaf Curl Virus (SPLCV) ...

  20. Notes on the ecology of rolled-leaf hispines (Chrysomelidae, Cassidinae) at La Gamba (Costa Rica).

    PubMed

    Schmitt, Michael; Frank, Meike

    2013-01-01

    A total of 301 adult hispine beetles of the genera Cephaloleia and Chelobasis were found in rolled leaves of plants of 17 species of Zingiberales (families Costaceae, Heliconiaceae, Maranthaceae, Musaceae, and Zingiberaceae) during a field study at La Gamba, Golfito region, Costa Rica. Of these beetles, Cephaloleia belti was recorded from 12 potential host plant species, C. distincta from 7, C. dilaticollis from 5, C., Chelobasis bicolor, C. championi, and C. histrionica from 3, Chelobasis perplexa and C. instabilis from 2, whereas C. trivittata from only one. Of the plant species, Heliconia latispatha had 7 beetle species in its leaf rolls, Calathea lutea had 5, H. imbricata and H. rostrata had 4, H. stricta and Musa paradisiaca had 3, H. wagneriana had 2, while on H. vaginalis, H. danielsiana, H. densiflora, H. longiflora, Calathea crotalifera, C. platystachya, Goeppertia lasiophylla, Alpinia purpurata, Costus pulverulentus and Costus barbatus, H. densiflora, H. vaginalis, and H. danielsana only hispines of one species were found. Cephaloleia belti occurred together with beetles of six other hispine species, whereas Cephaloleia trivittata never shared a leaf roll with another hispine species. The remaining beetle species aggregated with one to four other hispines. Adults of C. belti and C. championi were frequently seen, occasionally also with C. dilaticollis, C. histrionica, and Chelobasis perplexa, to co-occur with the carabid Calophaena ligata in the same leaf roll without any sign of interspecific aggression. A comparison of host choices and the phylogeny of the hispines and of their host plants revealed no signs that beetles used species level phylogenetic relationships within the Zingiberales to select food plants. Obviously, within this plant order, rolled-leaf hispines choose their plant hosts in a nearly opportunistic manner. Seemingly, they use differences among plants at higher taxonomic levels but within the Zingiberales, the availability of young

  1. Photosystem II functionality and antioxidant system changes during leaf rolling in post-stress emerging Ctenanthe setosa exposed to drought.

    PubMed

    Terzi, Rabiye; Saruhan, Neslihan; Sağlam, A; Nar, Hatice; Kadioğlu, A

    2009-12-01

    We studied the changes in antioxidant system and chlorophyll fluorescence parameters in post-stress emerging Ctenanthe setosa (Rosc.) Eichler (Marantaceae) plants (PSE plants) having reduced leaf area under drought stress causing leaf rolling and re-watering. PSE plants were compared to primary stressed plants (PS) in previous studies. The parameters were measured at different visual leaf rolling scores from 1 to 4 (1 is unrolled, 4 is tightly rolled and the others is intermediate form). Water potentials and stomatal conductance of leaves were gradually decreased during leaf rolling. Similarly, maximum quantum efficiency of open PS II center and quantum yield of PS II decreased during the rolling period. Non-photochemical quenching of chlorophyll fluorescence decreased at score 2 then increased while photochemical quenching did not change during leaf rolling. Electron transport rate decreased only at score 4 but approximately reached to score 1 level after re-watering. Superoxide dismutase activity was not constant at all leaf rolling scores. Ascorbate peroxidase, catalase and glutathione reductase activities generally tended to increase during leaf rolling. Lipid peroxidation and H 2 O 2 content increased at score 2 but decreased at the later scores. On the other hand, O 2 .- production increased during the rolling period. After re-watering of the plants having score 4 of leaf rolling, antioxidant enzyme activities were lower than those of score 1. Other physiological parameters also tended to reach the value of score 1. The results indicated that PSE plants gained drought tolerance by reducing leaf area effectively induced their antioxidant systems and protected the photosynthesis under drought stress similar to PS plants.

  2. Association of tomato leaf curl Sudan virus with leaf curl disease of tomato in Jeddah, Saudi Arabia.

    PubMed

    Sohrab, Sayed Sartaj; Yasir, Muhammad; El-Kafrawy, Sherif Ali; Abbas, Ayman T; Mousa, Magdi Ali Ahmed; Bakhashwain, Ahmed A

    2016-06-01

    Tomato is an important vegetable crop and its production is adversely affected by leaf curl disease caused by begomovirus. Leaf curl disease is a serious concern for tomato crops caused by begomovirus in Jeddah, Kingdom of Saudi Arabia. Tomato leaf curl disease has been shown to be mainly caused either by tomato leaf curl Sudan virus or tomato yellow leaf curl virus as well as tomato leaf curl Oman virus. Many tomato plants infected with monopartite begomoviruses were also found to harbor a symptom enhancing betasatellites. Here we report the association of tomato leaf curl Sudan virus causing leaf curl disease of tomato in Jeddah, Kingdom of Saudi Arabia. The complete genome sequence analysis showed highest (99.9 %) identity with tomato leaf curl Sudan virus causing leaf curl disease in Arabian Peninsula. In phylogenetic relationships analysis, the identified virus formed closest cluster with tomato leaf curl Sudan virus. In recombination analysis study, the major parent was identified as tomato leaf curl Sudan virus. Findings of this study strongly supports the associated virus is a variant of tomato leaf curl Sudan virus causing disease in Sudan, Yemen and Arabian Peninsula. The betasatellites sequence analysis showed highest identity (99.8 %) with tomato leaf curl betasatellites-Amaranthus-Jeddah. The phylogenetic analysis result based on betasatellites formed closed cluster with tomato yellow leaf curl Oman betasatellites. The importance of these findings and occurrence of begomovirus in new geographic regions causing leaf curl disease of tomato in Jeddah, Kingdom of Saudi Arabia are discussed.

  3. Rolling-leaf14 is a 2OG-Fe (II) oxygenase family protein that modulates rice leaf rolling by affecting secondary cell wall formation in leaves.

    PubMed

    Fang, Likui; Zhao, Fangming; Cong, Yunfei; Sang, Xianchun; Du, Qing; Wang, Dezhong; Li, Yunfeng; Ling, Yinghua; Yang, Zhenglin; He, Guanghua

    2012-06-01

    As an important agronomic trait, leaf rolling in rice (Oryza sativa L.) has attracted much attention from plant biologists and breeders. Moderate leaf rolling increases the amount of photosynthesis in cultivars and hence raises grain yield. Here, we describe the map-based cloning of the gene RL14, which was found to encode a 2OG-Fe (II) oxygenase of unknown function. rl14 mutant plants had incurved leaves because of the shrinkage of bulliform cells on the adaxial side. In addition, rl14 mutant plants displayed smaller stomatal complexes and decreased transpiration rates, as compared with the wild type. Defective development could be rescued functionally by the expression of wild-type RL14. RL14 was transcribed in sclerenchymatous cells in leaves that remained wrapped inside the sheath. In mature leaves, RL14 accumulated mainly in the mesophyll cells that surround the vasculature. Expression of genes related to secondary cell wall formation was affected in rl14-1 mutants, and cellulose and lignin content were altered in rl14-1 leaves. These results reveal that the RL14 gene affects water transport in leaves by affecting the composition of the secondary cell wall. This change in water transport results in water deficiency, which is the major reason for the abnormal shape of the bulliform cells.

  4. Transmission of Sweet Potato Leaf Curl Virus by Bemisia tabaci

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sweetpotato, Ipomoea batatas (L.) Lam. (Solanales: Convolvulaceae), is an important world food crop, and Asia is the focal production region. Because it is vegetatively propagated, sweetpotato is especially prone to accumulate infections by several viruses. Sweet potato leaf curl virus (SPLCV) (ss...

  5. Mining cotton germplasm resources to fight Cotton Leaf Curl Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CLCuV (Cotton Leaf Curl Virus) is a major threat to cotton production in Pakistan and parts of India and has been reported in cotton producing countries in Africa, as well as China and Uzbekistan. Identifying sources of resistance to CLCuV helps not only countries such as Pakistan where the virus is...

  6. Virus Hunting: Discovery of New Episomal Circular Viruses by Rolling Circle Techniques.

    PubMed

    Vanmechelen, Bert; Rector, Annabel; Maes, Piet

    2017-02-06

    Many methods for the discovery of novel viruses are based on amplification of the virus using consensus or degenerate PCR primers. A downside of this approach is that it requires prior knowledge of the viral nucleotide sequence to be applicable. Presented in this unit is a method for the sequence-independent amplification of circular viral genomes that is based on the rolling-circle mechanism used by certain viruses in their natural replication cycle. The amplification of the virus of interest is coupled to the isolation of the viral genome by gel extraction following a restriction digestion. Once isolated, the sequence of the viral genome can be determined by nanopore sequencing, a rapid and inexpensive next-generation sequencing technology that generates long reads in real time. The method described in this unit was originally developed for the discovery of papillomaviruses, but can be used for the identification of all types of circular DNA viruses. © 2017 by John Wiley & Sons, Inc.

  7. The complete nucleotide sequence of pelargonium leaf curl virus.

    PubMed

    McGavin, Wendy J; MacFarlane, Stuart A

    2016-05-01

    Investigation of a tombusvirus isolated from tulip plants in Scotland revealed that it was pelargonium leaf curl virus (PLCV) rather than the originally suggested tomato bushy stunt virus. The complete sequence of the PLCV genome was determined for the first time, revealing it to be 4789 nucleotides in size and to have an organization similar to that of the other, previously described tombusviruses. Primers derived from the sequence were used to construct a full-length infectious clone of PLCV that recapitulates the disease symptoms of leaf curling in systemically infected pelargonium plants.

  8. Joint Mapping and Allele Mining of the Rolled Leaf Trait in Rice (Oryza sativa L.)

    PubMed Central

    Wang, Chunchao; Nafisah; Joseph, Charles; Zhang, Wenzhong; Xu, Jianlong; Li, Zhikang

    2016-01-01

    The rolled leaf trait, long considered to be a key component of plant architecture, represents an important target trait for improving plant architecture at the population level. We therefore performed linkage mapping using a set of 262 highly variable RILs from two rice cultivars (Minghui 63 and 02428) with minor differences in leaf rolling index (LRI) in conjunction with GWAS mapping of a random subset of the 1127 germplasms from the 3K Rice Genomes Project (3K Rice). A total of seven main-effect loci were found to underlie the transgressive segregation of progenies from parents with minor differences in LRI. Five of these loci were previously identified and two (qRl7b and qRl9b) are newly reported with additional evidence from GWAS mapping for qRl7b. A total of 18 QTLs were identified by GWAS, including four newly identified QTLs. Six QTLs were confirmed by linkage mapping with the above RIL population, and 83.3% were found to be consistent with previously reported loci based on comparative mapping. We also performed allele mining with representative SNPs and identified the elite germplasms for the improvement of rolled leaf trait. Most favorable alleles at the detected loci were contributed by various 3K Rice germplasms. By a re-scanning of the candidate region with more saturated SNP markers, we dissected the region harboring gRl4-2 into three subregions, in which the average effect on LRI was 3.5% with a range from 2.4 to 4.1% in the third subregion, suggesting the presence of a new locus or loci within this region. The representative SNPs for favorable alleles in the reliable QTLs which were consistently identified in both bi-parental mapping and GWAS, such as qRl4, qRl5, qRl6, qRl7a, and qRl7b will be useful for future molecular breeding programs for ideal plant type in rice. PMID:27441398

  9. Carrot yellow leaf virus Is Associated with Carrot Internal Necrosis

    PubMed Central

    Adams, Ian P.; Skelton, Anna; Macarthur, Roy; Hodges, Tobias; Hinds, Howard; Flint, Laura; Nath, Palash Deb; Boonham, Neil; Fox, Adrian

    2014-01-01

    Internal necrosis of carrot has been observed in UK carrots for at least 10 years, and has been anecdotally linked to virus infection. In the 2009 growing season some growers had up to 10% of yield with these symptoms. Traditional diagnostic methods are targeted towards specific pathogens. By using a metagenomic approach with high throughput sequencing technology, other, as yet unidentified causes of root necrosis were investigated. Additionally a statistical analysis has shown which viruses are most closely associated with disease symptoms. Carrot samples were collected from a crop exhibiting root necrosis (102 Affected: 99 Unaffected) and tested for the presence of the established carrot viruses: Carrot red leaf virus (CtRLV), Carrot mottle virus (CMoV), Carrot red leaf associated viral RNA (CtRLVaRNA) and Parsnip yellow fleck virus (PYFV). The presence of these viruses was not associated with symptomatic carrot roots either as single viruses or in combinations. A sub-sample of carrots of mixed symptom status was subjected to MiSeq sequencing. The results from these tests suggested Carrot yellow leaf virus (CYLV) was associated with symptomatic roots. Additionally a novel Torradovirus, a novel Closterovirus and two novel Betaflexiviradae related plant viruses were detected. A specific diagnostic test was designed for CYLV. Of the 102 affected carrots, 98% were positive for CYLV compared to 22% of the unaffected carrots. From these data we conclude that although we have yet to practically demonstrate a causal link, CYLV appears to be strongly associated with the presence of necrosis of carrots. PMID:25365290

  10. Notes on the ecology of rolled-leaf hispines (Chrysomelidae, Cassidinae) at La Gamba (Costa Rica)1

    PubMed Central

    Schmitt, Michael; Frank, Meike

    2013-01-01

    Abstract A total of 301 adult hispine beetles of the genera Cephaloleia and Chelobasis were found in rolled leaves of plants of 17 species of Zingiberales (families Costaceae, Heliconiaceae, Maranthaceae, Musaceae, and Zingiberaceae) during a field study at La Gamba, Golfito region, Costa Rica. Of these beetles, Cephaloleia belti was recorded from 12 potential host plant species, C. distincta from 7, C. dilaticollis from 5, C., Chelobasis bicolor, C. championi, and C. histrionica from 3, Chelobasis perplexa and C. instabilis from 2, whereas C. trivittata from only one. Of the plant species, Heliconia latispatha had 7 beetle species in its leaf rolls, Calathea lutea had 5, H. imbricata and H. rostrata had 4, H. stricta and Musa paradisiaca had 3, H. wagneriana had 2, while on H. vaginalis, H. danielsiana, H. densiflora, H. longiflora, Calathea crotalifera, C. platystachya, Goeppertia lasiophylla, Alpinia purpurata, Costus pulverulentus and Costus barbatus, H. densiflora, H. vaginalis, and H. danielsana only hispines of one species were found. Cephaloleia belti occurred together with beetles of six other hispine species, whereas Cephaloleia trivittata never shared a leaf roll with another hispine species. The remaining beetle species aggregated with one to four other hispines. Adults of C. belti and C. championi were frequently seen, occasionally also with C. dilaticollis, C. histrionica, and Chelobasis perplexa, to co-occur with the carabid Calophaena ligata in the same leaf roll without any sign of interspecific aggression. A comparison of host choices and the phylogeny of the hispines and of their host plants revealed no signs that beetles used species level phylogenetic relationships within the Zingiberales to select food plants. Obviously, within this plant order, rolled-leaf hispines choose their plant hosts in a nearly opportunistic manner. Seemingly, they use differences among plants at higher taxonomic levels but within the Zingiberales, the availability of

  11. Natural association of two different betasatellites with Sweet potato leaf curl virus in wild morning glory (Ipomoea purpurea) in India.

    PubMed

    Swapna Geetanjali, A; Shilpi, S; Mandal, Bikash

    2013-08-01

    Wild morning glory (Ipomoea purpurea) was observed to be affected by leaf curl and yellow vein diseases during summer-rainy season of 2009 in New Delhi, India. The virus was experimentally transmitted through whitefly, Bemisia tabaci to I. purpurea that reproduced the two distinct symptoms. Sequence analysis of multiple full-length clones obtained through rolling circle amplification from the leaf curl and yellow vein samples showed 91.8-95.3% sequence identity with Sweet potato leaf curl virus (SPLCV) and the isolates were phylogenetically distinct from those reported from Brazil, China, Japan and USA. Interestingly, two different betasatellites, croton yellow vein mosaic betasatellite and papaya leaf curl betasatellite were found with SPLCV in leaf curl and yellow vein diseases of I. purpurea, respectively. This study is the first report of occurrence of SPLCV in wild morning glory in India. SPLCV was known to infect other species of morning glory; our study revealed that I. purpurea, a new species of morning glory was a natural host of SPLCV. To date, betasatellite associated with SPLCV in Ipomoea spp. is not known. Our study provides evidence of natural association of two different betasatellites with SPLCV in leaf curl and yellow vein diseases of I. purpurea.

  12. Alfalfa Leaf Curl Virus: an Aphid-Transmitted Geminivirus.

    PubMed

    Roumagnac, Philippe; Granier, Martine; Bernardo, Pauline; Deshoux, Maëlle; Ferdinand, Romain; Galzi, Serge; Fernandez, Emmanuel; Julian, Charlotte; Abt, Isabelle; Filloux, Denis; Mesléard, François; Varsani, Arvind; Blanc, Stéphane; Martin, Darren P; Peterschmitt, Michel

    2015-09-01

    The family Geminiviridae comprises seven genera differentiated by genome organization, sequence similarity, and insect vector. Capulavirus, an eighth genus, has been proposed to accommodate two newly discovered highly divergent geminiviruses that presently have no known vector. Alfalfa leaf curl virus, identified here as a third capulavirus, is shown to be transmitted by Aphis craccivora. This is the first report of an aphid-transmitted geminivirus.

  13. Alfalfa Leaf Curl Virus: an Aphid-Transmitted Geminivirus

    PubMed Central

    Roumagnac, Philippe; Granier, Martine; Bernardo, Pauline; Deshoux, Maëlle; Ferdinand, Romain; Galzi, Serge; Fernandez, Emmanuel; Julian, Charlotte; Abt, Isabelle; Filloux, Denis; Mesléard, François; Varsani, Arvind; Blanc, Stéphane; Martin, Darren P.

    2015-01-01

    The family Geminiviridae comprises seven genera differentiated by genome organization, sequence similarity, and insect vector. Capulavirus, an eighth genus, has been proposed to accommodate two newly discovered highly divergent geminiviruses that presently have no known vector. Alfalfa leaf curl virus, identified here as a third capulavirus, is shown to be transmitted by Aphis craccivora. This is the first report of an aphid-transmitted geminivirus. PMID:26109720

  14. The relationship between leaf rolling and ascorbate-glutathione cycle enzymes in apoplastic and symplastic areas of Ctenanthe setosa subjected to drought stress.

    PubMed

    Saruhan, Neslihan; Terzi, Rabiye; Saglam, Aykut; Kadioglu, Asim

    2009-01-01

    The ascorbate-glutathione (ASC-GSH) cycle has an important role in defensive processes against oxidative damage generated by drought stress. In this study, the changes that take place in apoplastic and symplastic ASC-GSH cycle enzymes of the leaf and petiole were investigated under drought stress causing leaf rolling in Ctenanthe setosa (Rose.) Eichler (Marantaceae). Apoplastic and symplastic extractions of leaf and petiole were performed at different visual leaf rolling scores from 1 to 4 (1 is unrolled, 4 is tightly rolled and the others are intermediate forms). Glutathione reductase (GR), a key enzyme in the GSH regeneration cycle, and ascorbate (ASC) were present in apoplastic spaces of the leaf and petiole, whereas dehydroascorbate reductase (DHAR), which uses glutathione as reductant, monodehydroascorbate reductase (MDHAR), which uses NAD(P)H as reductant, and glutathione were absent. GR, DHAR and MDHAR activities increased in the symplastic and apoplastic areas of the leaf. Apoplastic and symplastic ASC and dehydroascorbate (DHA), the oxidized form of ascorbate, rose at all scores except score 4 of symplastic ASC in the leaf. On the other hand, while reduced glutathione (GSH) content was enhanced, oxidized glutathione (GSSG) content decreased in the leaf during rolling. As for the petiole, GR activity increased in the apoplastic area but decreased in the symplastic area. DHAR and MDHAR activities increased throughout all scores, but decreased to the score 1 level at score 4. The ASC content of the apoplast increased during leaf rolling. Conversely, symplastic ASC content increased at score 2, however decreased at the later scores. While the apoplastic DHA content declined, symplastic DHA rose at score 2, but later was down to the level of score 1. While GSH content enhanced during leaf rolling, GSSG content did not change except at score 2. As well, there were good correlations between leaf rolling and ASC-GSH cycle enzyme activities in the leaf (GR and DHAR

  15. Leaf-rolling sawflies (Hymenoptera, Pamphiliidae, Pamphiliinae) of Tianmushan Mountains, Zhejiang Province, China.

    PubMed

    Shinohara, Akihiko; Wei, Mei-Cai

    2016-02-02

    Two species of Neurotoma, six species of Onycholyda, and five species of Pamphilius are recorded from Tianmushan, Zhejiang Province, China, and a key is given to these three genera and 13 species. Three new species, Onycholyda atra Shinohara & Wei, sp. nov. from Zhejiang Province, O. fulvicornis Shinohara, sp. nov. from Shaanxi Province and Zhejiang Province, and Pamphilius padus Shinohara, sp. nov. from Zhejiang Province, are described. New distribution records are: Onycholyda shaanxiana Shinohara, 1999, from Hubei Province, Zhejiang Province and Guangxi Zhuang Autonomous Region, O. subquadrata (Maa, 1944) from Zhejiang Province, O. tianmushana Shinohara & Xiao, 2006, from Hunan Province and Jiangxi Province, Pamphilius palliceps Shinohara & Xiao, 2006, from Anhui Province, P. lizejiani Shinohara in Shinohara & Wei, 2012, from Zhejiang Province, P. shengi Wei in Wei & Xiao, 1999, from Hubei Province and Zhejiang Province, and P. qinlingicus Wei in Wu & Wei, 2010, from Zhejiang Province. The larva of P. padus feeds on Padus obtusata (Rosaceae) and that of P. palliceps feeds on Rosa multiflora (Rosaceae), both singly making a leaf-roll. Rubus peltatus (Rosaceae) is recorded as a host plant of O. atra based on the observation of oviposition.

  16. [Molecular detection of tomato yellow leaf curl virus (TYLCV)].

    PubMed

    Li, Chang-Bao; Cui, Yan-Ling; Zhang, Li-Ying; Li, Chuan-You

    2012-03-01

    Tomato yellow leaf curl virus (TYLCV) is currently considered as one of the most devastating viruses in cultivated tomatoes (Solanum lycopersicum) worldwide. We reported here the development of a PCR-based method to quickly detect TYLCV using the primer pairs (TYLCV-F: 5'-ACG CAT GCC TCT AAT CCA GTG TA-3' and TYLCV-R: 5'-CCA ATA AGG CGT AAG CGT GTA GAC-3'), which was designed based on the genome sequence of TYLCV. A TYLCV-specific band of 543 bp was amplified from infected tomato plants. This protocol provides a rapid, reliable, and sensitive tool for molecular detection and identification of TYLCV in the industrial seedling and virus resistance breeding to facilitate safe and sustainable production of tomato.

  17. Sweet Potato Leaf Curl Virus: Virus Reservoir in Species of Wild Morning Glory

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent increases in populations of the Sweetpotato leaf curl virus (SPLCV) vector, the sweetpotato whitefly, Bemisia tabaci (Gennadius), led to a dramatic increase in the disease in sweetpotato (Ipomoea batatas). Knowledge of crop or weed species that occur in sweetpotato growing areas and can serv...

  18. Pepper leaf curl Lahore virus requires the DNA B component of Tomato leaf curl New Delhi virus to cause leaf curl symptoms

    PubMed Central

    2010-01-01

    Background Begomoviruses are whitefly-transmitted geminiviruses with genomes that consist of either two components (known as DNA A and DNA B) or a single component (homologous to the DNA A component of bipartite begomoviruses). Monopartite begomoviruses are often associated with a symptom-modulating DNA satellite (collectively known as betasatellites). Both bipartite and monopartite begomoviruses with associated satellites have previously been identified in chillies showing leaf curl symptoms in Pakistan. Results A chilli plant (Capsicum annum) with chilli leaf curl disease symptoms was found to contain a begomovirus, a betasatellite and the DNA B component of Tomato leaf curl New Delhi virus (ToLCNDV). The begomovirus consisted of 2747 nucleotides and had the highest sequence identity (99%) with Pepper leaf curl Lahore virus (PepLCLV-[PK: Lah:04], acc. no. AM404179). Agrobacterium-mediated inoculation of the clone to Nicotiana benthamiana, induced very mild symptoms and low levels of viral DNA, detected in systemically infected leaves by PCR. No symptoms were induced in Nicotiana tabacum or chillies either in the presence or absence of a betasatellite. However, inoculation of PepLCLV with the DNA B component of ToLCNDV induced leaf curl symptoms in N. benthamiana, N. tabacum and chillies and viral DNA accumulated to higher levels in comparison to plants infected with just PepLCLV. Conclusions Based on our previous efforts aimed at understanding of diversity of begomoviruses associated with chillies, we propose that PepLCLV was recently mobilized into chillies upon its interaction with DNA B of ToLCNDV. Interestingly, the putative rep-binding iterons found on PepLCLV (GGGGAC) differ at two base positions from those of ToLCNDV (GGTGTC). This is the first experimental demonstration of the infectivity for a bipartite begomovirus causing chilli leaf curl disease in chillies from Pakistan and suggests that component capture is contributing to the emerging complexity of

  19. Association of a recombinant Cotton leaf curl Bangalore virus with yellow vein and leaf curl disease of okra in India.

    PubMed

    Venkataravanappa, V; Lakshminarayana Reddy, C N; Devaraju, A; Jalali, Salil; Krishna Reddy, M

    2013-09-01

    A begomovirus isolate (OY136A) collected from okra plants showing upward leaf curling, vein clearing, vein thickening and yellowing symptoms from Bangalore rural district, Karnataka, India was characterized. The sequence comparisons revealed that, this virus isolate share highest nucleotide identity with isolates of Cotton leaf curl Bangalore virus (CLCuBV) (AY705380) (92.8 %) and Okra enation leaf curl virus (81.1-86.2 %). This is well supported by phylogentic analysis showing, close clustering of the virus isolate with CLCuBV. With this data, based on the current taxonomic criteria for the genus Begomovirus, the present virus isolate is classified as a new strain of CLCuBV, for which CLCuBV-[India: Bangalore: okra: 2006] additional descriptor is proposed. The betasatellite (KC608158) associated with the virus is having more than 95 % sequence similarity with the cotton leaf curl betasatellites (CLCuB) available in the GenBank.The recombination analysis suggested, emergence of this new strain of okra infecting begomovirus might have been from the exchange of genetic material between BYVMV and CLCuMuV. The virus was successfully transmitted by whitefly and grafting. The host range of the virus was shown to be very narrow and limited to two species in the family Malvaceae, okra (Abelmoschus esculentus) and hollyhock (Althaea rosea), and four in the family Solanaceae.

  20. Evaluating Weeds as Hosts of Tomato yellow leaf curl virus.

    PubMed

    Smith, Hugh A; Seijo, Teresa E; Vallad, Gary E; Peres, Natalia A; Druffel, Keri L

    2015-08-01

    Bemisia tabaci (Gennadius) biotype B transmits Tomato yellow leaf curl virus (TYLCV), which affects tomato production globally. Prompt destruction of virus reservoirs is a key component of virus management. Identification of weed hosts of TYLCV will be useful for reducing such reservoirs. The status of weeds as alternate hosts of TYLCV in Florida remains unclear. In greenhouse studies, B. tabaci adults from a colony reared on TYLCV-infected tomato were established in cages containing one of four weeds common to horticultural fields in central and south Florida. Cages containing tomato and cotton were also infested with viruliferous whiteflies as a positive control and negative control, respectively. Whitefly adults and plant tissue were tested periodically over 10 wk for the presence of TYLCV using PCR. After 10 wk, virus-susceptible tomato plants were placed in each cage to determine if whiteflies descended from the original adults were still infective. Results indicate that Bidens alba, Emilia fosbergii, and Raphanus raphanistrum are not hosts of TYLCV, and that Amaranthus retroflexus is a host.

  1. Molecular characterization and phylogenetic analysis of sugarcane yellow leaf virus isolates from China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugarcane yellow leaf virus (SCYLV), the causal agent of sugarcane yellow leaf disease (YLD), was first reported in China in 2006. In order to determine the distribution existence of SCYLV in major sugarcane-growing provinces in China, leaf samples were collected from 22 sugarcane clones (Saccharum ...

  2. First report of Sugarcane yellow leaf virus infecting Columbus Grass (Sorghum almum) in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugarcane yellow leaf virus (SCYLV) [genus Polerovirus, family Luteoviridae] is the causal agent of sugarcane yellow leaf disease. SCYLV is widespread in Florida where sugarcane was the only known natural host of this virus. During spring 2015, we collected (leaves or stalks) and tested several gras...

  3. Chili leaf curl betasatellite is associated with a distinct recombinant begomovirus, Pepper leaf curl Lahore virus, in Capsicum in Pakistan.

    PubMed

    Tahir, Muhammad; Haider, Muhammad Saleem; Briddon, Rob W

    2010-04-01

    Capsium spp. are an important vegetable crop cultivated through Pakistan. Leaf curl disease is the major disease of Capsicum spp. in Pakistan caused by viruses. The disease has previously been shown to be associated with begomoviruses and betasatellites. We have cloned and sequenced a begomovirus and its associated betasatellite from Capsicum originating from central Pakistan. The begomovirus isolated was distinct from all previously characterised viruses and we propose the name Pepper leaf curl Lahore virus (PepLCLV) for this new species. Comparison of the sequence of PepLCLV with previously characterised begomoviruses shows it likely to have resulted from recombination between Papaya leaf curl virus and Chili leaf curl virus (ChiLCV), two species that have previously been identified in Pakistan. The betasatellite associated with PepLCLV in Capsicum was identified as Chili leaf curl betasatellite (ChLCB). This is the first identification of a cognate begomovirus for ChLCB infecting Capsicum, although this betasatellite has been shown in association with ChiLCV infecting potato in Pakistan. PepLCLV is one of an increasing number of monopartite begomoviruses shown to be associated with a betasatellite and one of the numerous species that affect Capsicum. In view of their only having been identified in Pakistan, PepLCLV and ChLCB likely represent a geographically distinct, Capsicum adapted, begomovirus-betasatellite complex.

  4. Ongoing geographical spread of Tomato yellow leaf curl virus.

    PubMed

    Mabvakure, Batsirai; Martin, Darren P; Kraberger, Simona; Cloete, Leendert; van Brunschot, Sharon; Geering, Andrew D W; Thomas, John E; Bananej, Kaveh; Lett, Jean-Michel; Lefeuvre, Pierre; Varsani, Arvind; Harkins, Gordon W

    2016-11-01

    Tomato yellow leaf curl virus (TYLCV) seriously impacts tomato production throughout tropical and sub-tropical regions of the world. It has a broad geographical distribution and continues to spread to new regions in the Indian and Pacific Oceans including Australia, New Caledonia and Mauritius. We undertook a temporally-scaled, phylogeographic analysis of all publicly available, full genome sequences of TYLCV, together with 70 new genome sequences from Australia, Iran and Mauritius. This revealed that whereas epidemics in Australia and China likely originated through multiple independent viral introductions from the East-Asian region around Japan and Korea, the New Caledonian epidemic was seeded by a variant from the Western Mediterranean region and the Mauritian epidemic by a variant from the neighbouring island of Reunion. Finally, we show that inter-continental scale movements of TYLCV to East Asia have, at least temporarily, ceased, whereas long-distance movements to the Americas and Australia are probably still ongoing.

  5. Molecular Characterization of Tomato leaf curl Palampur virus and Pepper leaf curl betasatellite Naturally Infecting Pumpkin (Cucurbita moschata) in India.

    PubMed

    Namrata, Jaiswal; Saritha, R K; Datta, D; Singh, M; Dubey, R S; Rai, A B; Rai, M

    2010-10-01

    Pumpkin cultivation in India is affected by severe incidence of a yellow vein mosaic disease. Tomato leaf curl New Delhi virus and Squash leaf curl China virus are known to be associated with this disease in India. We were able to identify a third begomovirus-Tomato leaf curl Palampur virus (ToLCPMV), from pumpkin showing typical symptoms of the disease at Varanasi based on the sequence of complete DNA-A genome of the virus. The complete DNA-A sequence of the virus shared more than 99% sequence identity with other ToLCPMV isolates available in the GenBank and clustered with them in the phylogenetic analysis. This betasatellite amplified from the same infected sample has been identified as Pepper leaf curl betasatellite (PepLCB) which also infects chilli in India. There was 92% sequence identity between the two isolates. This is the first report of natural infection of ToLCPMV on pumpkin and association of PepLCB with yellow vein mosaic disease of pumpkin in India.

  6. Cotton leaf curl Burewala virus with intact or mutant transcriptional activator proteins: complexity of cotton leaf curl disease.

    PubMed

    Kumar, Jitendra; Gunapati, Samatha; Alok, Anshu; Lalit, Adarsh; Gadre, Rekha; Sharma, Naresh C; Roy, Joy K; Singh, Sudhir P

    2015-05-01

    Cotton leaf curl disease (CLCuD) is a serious disease of cotton on the Indian subcontinent. In the present study, three cotton leaf curl viruses, cotton leaf curl Burewala virus (CLCuBuV), cotton leaf curl Kokhran virus (CLCuKoV) and cotton leaf curl Multan virus (CLCuMV), and their associated satellites, cotton leaf curl Multan betasatellite (CLCuMB) and cotton leaf curl Multan alphasatellite (CLCuMA), were detected. CLCuBuV with either intact (CLCuBuV-1) or mutant (CLCuBuV-2) transcriptional activator protein (TrAP) were detected in different plants. Agroinoculation with CLCuBuV-1 or CLCuBuV-2 together with CLCuMB and CLCuMA, resulted in typical leaf curling and stunting of tobacco plants. Inoculation with CLCuKoV or an isolate of CLCuMV (CLCuMV-2), together with CLCuMB and CLCuMA, induced severe leaf curling, while the other isolate of CLCuMV (CLCuMV-1), which was recombinant in origin, showed mild leaf curling in tobacco. To investigate the effect of intact or mutant TrAP and also the recombination events, CLCuBuV-1, CLCuBuV-2, CLCuMV-1 or CLCuMV-2 together with the satellites (CLCuMA and CLCuMB) were transferred to cotton via whitefly-mediated transmission. Cotton plants containing CLCuBuV-1, CLCuBuV-2 or CLCuMV-2 together with satellites showed curling and stunting, whereas the plants having CLCuMV-1 and the satellites showed only mild and indistinguishable symptoms. CLCuBuV-1 (intact TrAP) showed severe symptoms in comparison to CLCuBuV-2 (mutant TrAP). The present study reveals that two types of CLCuBuV, one with an intact TrAP and the other with a mutant TrAP, exist in natural infection of cotton in India. Additionally, CLCuMuV-1, which has a recombinant origin, induces mild symptoms in comparison to the other CLCuMV isolates.

  7. Standardized RT-PCR conditions for detection and identification of eleven viruses of potato and Potato spindle tuber viroid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Standardized RT-PCR procedures were developed and validated for detection of Alfalfa mosaic virus (AMV), Impatiens necrotic spot virus (INSV), Tobacco rattle virus (TRV), Tomato spotted wilt virus (TSWV), Potato leaf roll virus (PLRV), Potato mop top virus (PMTV), Potato virus A (PVA), Potato viru...

  8. Frequent Occurrence of Tomato Leaf Curl New Delhi Virus in Cotton Leaf Curl Disease Affected Cotton in Pakistan

    PubMed Central

    Zaidi, Syed Shan-e-Ali; Shafiq, Muhammad; Amin, Imran; Scheffler, Brian E.; Scheffler, Jodi A.; Briddon, Rob W.; Mansoor, Shahid

    2016-01-01

    Cotton leaf curl disease (CLCuD) is the major biotic constraint to cotton production on the Indian subcontinent, and is caused by monopartite begomoviruses accompanied by a specific DNA satellite, Cotton leaf curl Multan betasatellite (CLCuMB). Since the breakdown of resistance against CLCuD in 2001/2002, only one virus, the “Burewala” strain of Cotton leaf curl Kokhran virus (CLCuKoV-Bur), and a recombinant form of CLCuMB have consistently been identified in cotton across the major cotton growing areas of Pakistan. Unusually a bipartite isolate of the begomovirus Tomato leaf curl virus was identified in CLCuD-affected cotton recently. In the study described here we isolated the bipartite begomovirus Tomato leaf curl New Delhi virus (ToLCNDV) from CLCuD-affected cotton. To assess the frequency and geographic occurrence of ToLCNDV in cotton, CLCuD-symptomatic cotton plants were collected from across the Punjab and Sindh provinces between 2013 and 2015. Analysis of the plants by diagnostic PCR showed the presence of CLCuKoV-Bur in all 31 plants examined and ToLCNDV in 20 of the samples. Additionally, a quantitative real-time PCR analysis of the levels of the two viruses in co-infected plants suggests that coinfection of ToLCNDV with the CLCuKoV-Bur/CLCuMB complex leads to an increase in the levels of CLCuMB, which encodes the major pathogenicity (symptom) determinant of the complex. The significance of these results are discussed. PMID:27213535

  9. First report of an alphasatellite associated with Okra enation leaf curl virus.

    PubMed

    Chandran, S A; Packialakshmi, R M; Subhalakshmi, K; Prakash, C; Poovannan, K; Nixon Prabu, A; Gopal, P; Usha, R

    2013-06-01

    An alphasatellite DNA associated with Okra enation leaf curl virus (OELCuV) which causes enation and leaf curling in okra (Abelmoschus esculentus) plants was characterized. The full-length DNA comprises 1,350 nucleotides and shows typical genome organization of an alphasatellite. It shows the highest nucleotide sequence identity (79.7 %) to Hollyhock yellow vein virus-associated symptomless alphasatellite (HoYVSLA). This is the first report of the association of an alphasatellite with OELCuV from India.

  10. Novel Synthetic Promoters from the Cestrum Yellow Leaf Curling Virus.

    PubMed

    Sahoo, Dipak Kumar; Sarkar, Shayan; Maiti, Indu B; Dey, Nrisingha

    2016-01-01

    Constitutive promoters direct gene expression uniformly in most tissues and cells at all stages of plant growth and development; they confer steady levels of transgene expression in plant cells and hence their demand is high in plant biology. The gene silencing due to promoter homology can be avoided by either using diverse promoters isolated from different plant and viral genomes or by designing synthetic promoters. The aim of this chapter was to describe the basic protocols needed to develop and analyze novel, synthetic, nearly constitutive promoters from Cestrum yellow leaf curling virus (CmYLCV) through promoter/leader deletion and activating cis-sequence analysis. We also describe the methods to evaluate the strength of the promoters efficiently in various transient expression systems like agroinfiltration assay, gene-gun method, and assay in tobacco protoplasts. Besides, the detailed methods for developing transgenic plants (tobacco and Arabidopsis) for evaluation of the promoter using the GUS reporter gene are also described. The detailed procedure for electrophoretic mobility shift assay (EMSA) coupled with super-shift EMSA analysis are also described for showing the binding of tobacco transcription factor, TGA1a to cis-elements in the CmYLCV distal promoter region.

  11. Sweet Potato Leaf Curl Virus: Efficiency of Acquisition, Retention and Transmission by Bemisia tabaci (Hemiptera: Aleyrodidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sweetpotato whitefly, Bemisia tabaci (Gennadius), is a global pest which damages plants directly by feeding on leaves. Moreover, the problem is compounded because B. tabaci also vectors numerous plant viruses, including Begomoviruses (Geminiviridae) such as the Sweet Potato Leaf Curl Virus (SPL...

  12. Biological characterization and complete genomic sequence of Carrot thin leaf virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The host range of a cilantro isolate of Carrot thin leaf virus (CTLV-Cs) was determined to include 15 plant species. The virus was also transmitted to 9 of 11 tested apiaceous species by aphids. Complete genomic sequences of CTLV-Cs and a carrot isolate of CTLV were determined. Their genomic sequenc...

  13. Whitefly transmission of Sweet potato leaf curl virus in sweetpotato germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sweetpotato, Ipomoea batatas (L.) Lam., is among an extensive number of plant species attacked by Bemisia tabaci (Gennadius). Because this important world food crop is vegetatively propagated, it can conveniently accumulate infections by several viruses. Sweet potato leaf curl virus (SPLCV) (ssDNA...

  14. Management of sweet potato leaf curl virus in sweetpotatoes using insecticides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sweetpotato leaf curl virus (SPLCV), which is transmitted by the sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), can severely affect yields of commercial sweetpotatoes, Ipomoea batatas (L.) Lam. (Convolvulaceae). This virus occurs every year at the U.S. Vegetable Laborato...

  15. Significant increase in titer of Raspberry bushy dwarf virus when present in combination with Raspberry leaf mottle virus and its effect on raspberry plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Raspberry crumbly fruit is a virus-induced disease widespread in the Pacific Northwest (PNW). Raspberry bushy dwarf virus (RBDV) has been attributed as the causal agent of the disease. Recently, the identification of two new viruses: Raspberry leaf mottle virus (RLMV) and Raspberry latent virus (RpL...

  16. Phylogenetic lineage of Tobacco leaf curl virus in Korea and estimation of recombination events implicated in their sequence variation.

    PubMed

    Park, Jungan; Lee, Hyejung; Kim, Mi-Kyung; Kwak, Hae-Ryun; Auh, Chung-Kyoon; Lee, Kyeong-Yeoll; Kim, Sunghan; Choi, Hong-Soo; Lee, Sukchan

    2011-08-01

    New strains of Tobacco leaf curl virus (TbLCV) were isolated from tomato plants in four different local communities of Korea, and hence were designated TbLCV-Kr. Phylogenetic analysis of the sequences of the whole genome and of individual ORFs of these viruses indicated that they are closely related to the Tobacco leaf curl Japan virus (TbLCJV) cluster, which includes Honeysuckle yellow vein virus (HYVV), Honeysuckle yellow vein mosaic virus (HYVMV), and TbLCJV isolates. Four putative recombination events were recognized within these virus sequences, suggesting that the sequence variations observed in these viruses may be attributable to intraspecific and interspecific recombination events involving some TbLCV-Kr isolates, Papaya leaf curl virus (PaLCV), and a local isolate of Tomato yellow leaf curl virus (TYLCV).

  17. Host range and genetic diversity of croton yellow vein mosaic virus, a weed-infecting monopartite begomovirus causing leaf curl disease in tomato.

    PubMed

    Pramesh, D; Mandal, Bikash; Phaneendra, Chigurupati; Muniyappa, V

    2013-03-01

    Croton yellow vein mosaic virus (CYVMV) is a widely occurring begomovirus in Croton bonplandianum, a common weed in the Indian subcontinent. In this study, CYVMV (genus Begomovirus, family Geminiviridae) was transmitted by whiteflies (Bemisia tabaci) to as many as 35 plant species belonging to 11 families, including many vegetables, tobacco varieties, ornamentals and weeds. CYVMV produced bright yellow vein symptoms in croton, whereas in all the other host species, the virus produced leaf curl symptoms. CYVMV produced leaf curl in 13 tobacco species and 22 cultivars of Nicotiana tabacum and resembled tobacco leaf curl virus (TobLCV) in host reactions. However, CYVMV was distinguished from TobLCV in four differential hosts, Ageratum conyzoides, C. bonplandianum, Euphorbia geniculata and Sonchus bracyotis. The complete genome sequences of four isolates originating from northern, eastern and southern India revealed that a single species of DNA-A and a betasatellite, croton yellow vein mosaic betasatellite (CroYVMB) were associated with the yellow vein mosaic disease of croton. The sequence identity among the isolates of CYVMV DNA-A and CroYVMB occurring in diverse plant species was 91.8-97.9 % and 83.3-100 %, respectively. The CYVMV DNA-A and CroYVMB generated through rolling-circle amplification of the cloned DNAs produced typical symptoms of yellow vein mosaic and leaf curling in croton and tomato, respectively. The progeny virus from both the croton and tomato plants was transmitted successfully by B. tabaci. The present study establishes the etiology of yellow vein mosaic disease of C. bonplandianum and provides molecular evidence that a weed-infecting monopartite begomovirus causes leaf curl in tomato.

  18. Characterization and distribution of tomato yellow margin leaf curl virus, a begomovirus from Venezuela.

    PubMed

    Nava, A; Londoño, A; Polston, J E

    2013-02-01

    A begomovirus causing mottling and leaf deformation in tomato from the State of Mérida was cloned and sequenced. The virus has a bipartite genome comprised of a DNA-A (2,572 nucleotides) and a DNA-B (2,543 nucleotides) with a genome organization typical of New World begomoviruses. Both components share a common region of 115 nucleotides with 98 % sequence identity. Phylogenetic analysis indicated that while no virus sequences were closely related, the A component was distantly related to those of two other tomato-infecting viruses, tomato leaf deformation virus and Merremia mosaic virus; and the DNA-B, to those of pepper huasteco yellow vein virus and Rhynchosia golden mosaic Yucatan virus. The DNA-A and DNA-B sequences were submitted to GenBank (accession no. AY508993 and AY508994, respectively) and later accepted by the International Committee on Taxonomy of Viruses as the genome of a member of a unique virus species with the name Tomato yellow margin leaf curl virus (TYMLCV). Tomato (Solanum lycopersicum L. 'Fl. Lanai') plants inoculated with cloned TYMLCV DNA-A and DNA-B became systemically infected and showed chlorotic margins and leaf curling. The distribution of TYMLCV in tomato-producing states in Venezuela was determined by nucleic acid spot hybridization analysis of 334 tomato leaf samples collected from ten states using a TYMLCV-specific probe and confirmed by PCR and sequencing of the PCR fragment. TYMLCV was detected in samples from the states of Aragua, Guárico, and Mérida, suggesting that TYMLCV is widely distributed in Venezuela.

  19. Tomato leaf curl Karnataka virus from Bangalore, India, Appears to be a Recombinant Begomovirus.

    PubMed

    Chatchawankanphanich, Orawan; Maxwell, Douglas P

    2002-06-01

    ABSTRACT The genome of Tomato leaf curl virus (ToLCV) from Bangalore, India, a whitefly-transmitted geminivirus, was cloned (pIND9) and sequenced. The circular DNA of 2,759 nucleotides (U38239) is organized similarly to that of other begomoviruses with monopartite genomes. Comparison of the nucleotide sequence of pIND9 with other tomato-associated begomoviruses from India (Tomato leaf curl Bangalore virus [ToLCBV, Z48182]) and Tomato leaf curl New Delhi virus-Severe (ToLCNdV-Svr, U15015) showed moderate DNA sequence identities (82 to 87%) between capsid protein (CP) genes but low identities (66 to 67%) for the intergenic regions and the replication-associated protein (Rep) genes (75 to 81% identity). Phylogenetic trees generated with nucleotide sequences of the Rep and CP genes of 26 begomoviruses indicated that this ToLCV is distinct from other begomoviruses and that it may be a recombinant virus derived from at least three different viral lineages. Tomatoes (Lycopersicon esculentum) inoculated with the cloned DNA monomer of ToLCV (pIND9) via particle bombardment developed leaf curling and yellowing symptoms. The virus was transmitted by Bemisia tabaci biotype B from tomatoes infected via particle bombardment to healthy tomatoes and by sap inoculation from infected tomatoes to tomato, Nicotiana benthamiana and N. tabacum. This ToLCV is a distinct member of the genus Begomovirus from India that differs from the previously characterized Tomato leaf curl Sadasivanagar virus isolate Bangalore 1 (L12739), ToLCBV (Z48182), ToLCBV isolate Bangalore 4 (AF165098), and the bipartite ToLCNdV (U15015, U15016). Thus, this ToLCV is named Tomato leaf curl Karnataka virus (ToLCKV).

  20. Functional Analysis of Cotton Leaf Curl Kokhran Virus/Cotton Leaf Curl Multan Betasatellite RNA Silencing Suppressors

    PubMed Central

    Saeed, Muhammad; Briddon, Rob W.; Dalakouras, Athanasios; Krczal, Gabi; Wassenegger, Michael

    2015-01-01

    In South Asia, Cotton leaf curl disease (CLCuD) is caused by a complex of phylogenetically-related begomovirus species and a specific betasatellite, Cotton leaf curl Multan betasatellite (CLCuMuB). The post-transcriptional gene silencing (PTGS) suppression activities of the transcriptional activator protein (TrAP), C4, V2 and βC1 proteins encoded by Cotton leaf curl Kokhran virus (CLCuKoV)/CLCuMuB were assessed in Nicotiana benthamiana. A variable degree of local silencing suppression was observed for each viral protein tested, with V2 protein exhibiting the strongest suppression activity and only the C4 protein preventing the spread of systemic silencing. The CLCuKoV-encoded TrAP, C4, V2 and CLCuMuB-encoded βC1 proteins were expressed in Escherichia coli and purified. TrAP was shown to bind various small and long nucleic acids including single-stranded (ss) and double-stranded (ds) RNA and DNA molecules. C4, V2, and βC1 bound ssDNA and dsDNA with varying affinities. Transgenic expression of C4 under the constitutive 35S Cauliflower mosaic virus promoter and βC1 under a dexamethasone inducible promoter induced severe developmental abnormalities in N. benthamiana. The results indicate that homologous proteins from even quite closely related begomoviruses may differ in their suppressor activity and mechanism of action. The significance of these findings is discussed. PMID:26512705

  1. Development of Cotton leaf curl virus resistant transgenic cotton using antisense ßC1 gene.

    PubMed

    Sohrab, Sayed Sartaj; Kamal, Mohammad A; Ilah, Abdul; Husen, Azamal; Bhattacharya, P S; Rana, D

    2016-05-01

    Cotton leaf curl virus (CLCuV) is a serious pathogen causing leaf curl disease and affecting the cotton production in major growing areas. The transgenic cotton (Gossypium hirsutum cv. Coker 310) plants were developed by using βC1 gene in antisense orientation gene driven by Cauliflower mosaic virus-35S promoter and nos (nopaline synthase) terminator and mediated by Agrobacterium tumefaciens transformation and somatic embryogenesis system. Molecular confirmation of the transformants was carried out by polymerase chain reaction (PCR) and Southern blot hybridization. The developed transgenic and inoculated plants remained symptomless till their growth period. In conclusion, the plants were observed as resistant to CLCuV.

  2. Infectious clones of Tomato leaf curl Palampur virus with a defective DNA B and their pseudo-recombination with Tomato leaf curl New Delhi virus

    PubMed Central

    2011-01-01

    Background Tomato leaf curl Palampur virus (ToLCPMV) is a bipartite begomovirus which has been reported from India and Iran but infectious clones have not been obtained. We have previously shown the association of Zucchini yellow mosaic virus (ZYMV), a potyvirus, with severe leaf curl disease of muskmelon in Pakistan. However, the severity of symptoms in the field and yield losses led us to believe that some other agent, such as a begomovirus, could be associated with the disease. Results A bipartite begomovirus associated with a severe yellow leaf curl disease on muskmelon in Pakistan has been characterized. Analysis of the complete nucleotide sequence of the DNA A and DNA B components of the begomovirus showed that it has the highest DNA sequence identity with ToLCPMV. However, the gene encoding the nuclear shuttle protein (NSP) was truncated in comparison to previously characterised isolates. Agrobacterium-mediated inoculation of Nicotiana benthamiana with the ToLCPMV clones obtained here did not result in symptoms. However, inoculation of plants with the DNA A component of ToLCPMV and the DNA B component of Tomato leaf curl New Delhi virus (ToLCNDV) lead to systemic infection with leaf curl symptoms. This suggested that the lack of infectivity of the ToLCPMV clones was due to the defect in DNA B. The DNA B of ToLCPMV was able to move systemically when inoculated with DNA A of the either virus. Agro-infiltration of muskmelon with the DNA A and DNA B components of ToLCPMV did not lead to symptomatic infection whereas inoculation with the DNA A with the DNA B of ToLCNDV resulted in a hypersensitive response (HR) along the veins. Additionally, agro-infiltration of muskmelon with a construct for the expression of the NSP gene of ToLCNDV under the control of the cauliflower mosaic virus 35S promoter induced a HR, suggesting that this is the gene causing the HR. Conclusions Both ToLCPMV and ZYMV are associated with muskmelon leaf curl disease in Pakistan. However, the

  3. Molecular characterization of Tobacco leaf curl Pusa virus, a new monopartite Begomovirus associated with tobacco leaf curl disease in India.

    PubMed

    Singh, Manoj K; Singh, K; Haq, Q M R; Mandal, B; Varma, A

    2011-10-01

    Leaf curl disease of tobacco (TbLCD) is endemic in India. A monopartite Begomovirus, a betasatellite and an alphasatellite were found associated with the disease in Pusa, Bihar. The DNA-A of the Begomovirus associated with TbLCD in Pusa, Bihar was found to comprise of 2707 nt with a typical Old World begomovirus-like genome organization. The full-length sequence of DNA-A [HQ180391] showed that the Pusa isolate is a newly described member of the genus Begomovirus, as it had <89% sequence homology with DNA-A of all the known begomoviruses. The isolate is tentatively named as Tobacco leaf curl Pusa virus [India:Pusa:2010]. The betasatellite (HQ180395) associated with TbLCD in Pusa was identified as a variant of Tomato leaf curl Bangladesh betasatellite [IN:Raj:03], with which it shared 90.4% sequence identity. The alphasatellite (HQ180392) associated with the disease had highest 87% nucleotide sequence identity with Tomato leaf curl alphasatellite. The Begomovirus, betasatellite, and alphasatellite associated with TbLCD in Pusa, Bihar, India were found to be recombinants of extant begomoviruses, betasatellites and alphasatellites spreading in the Indian sub-continent and South-East Asia.

  4. Molecular diversity of Cotton leaf curl Gezira virus isolates and their satellite DNAs associated with okra leaf curl disease in Burkina Faso

    PubMed Central

    2010-01-01

    Okra leaf curl disease (OLCD) is a major constraint on okra (Abelmoschus esculentus) production and is widespread in Africa. Using a large number of samples representative of the major growing regions in Burkina Faso (BF), we show that the disease is associated with a monopartite begomovirus and satellite DNA complexes. Twenty-three complete genomic sequences of Cotton leaf curl Gezira virus (CLCuGV) isolates associated with OLCD, sharing 95 to 99% nucleotide identity, were cloned and sequenced. Six betasatellite and four alphasatellite (DNA-1) molecules were also characterized. The six isolates of betasatellite associated with CLCuGV isolates correspond to Cotton leaf curl Gezira betasatellite (CLCuGB) (88 to 98% nucleotide identity). One isolate of alphasatellite is a variant of Cotton leaf curl Gezira alphasatellite (CLCuGA) (89% nucleotide identity), whereas the three others isolates appear to correspond to a new species of alphasatellite (CLCuGA most similar sequence present 52 to 60% nucleotide identity), provisionally named Okra leaf curl Burkina Faso alphasatellite (OLCBFA). Recombination analysis of the viruses demonstrated the interspecies recombinant origin of all CLCuGV isolates, with parents being close to Hollyhock leaf crumple virus (AY036009) and Tomato leaf curl Diana virus (AM701765). Combined with the presence of satellites DNA, these results highlight the complexity of begomoviruses associated with OLCD. PMID:20178575

  5. Complete nucleotide sequence of Rose yellow leaf virus, a new member of the family Tombusviridae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genome of the Rose yellow leaf virus (RYLV) has been determined to be 3918 nucleotides containing seven open reading frames (ORFs). ORF1 encodes a 27 kDa peptide (p27). ORF2 shares a common start codon with ORF1 and continues through the amber stop codon of p27 to encode a 87 kDa (p87) protein t...

  6. Multiple Introductions of the Old World Begomovirus Tomato yellow leaf curl virus into the New World▿

    PubMed Central

    Duffy, Siobain; Holmes, Edward C.

    2007-01-01

    A phylogenetic analysis of three genomic regions revealed that Tomato yellow leaf curl virus (TYLCV) from western North America is distinct from TYLCV isolated in eastern North America and the Caribbean. This analysis supports a second introduction of this Old World begomovirus into the New World, most likely from Asia. PMID:17827315

  7. Papaya is not a host for Tomato Yellow Leaf Curl Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The economic value of tomato production is threatened by tomato yellow leaf-curl virus TYLCV and its vector, the silverleaf whitefly Bemisia tabaci biotype B (Gennadius) (Hemiptera: Aleyrodidae). Use of papaya Carica papaya L. as a banker plant for a whitefly parasitoid shows promise as a whitefly m...

  8. Survey of apple chlorotic leaf spot virus and apple stem grooving virus occurrence in Korea and frequency of mixed infections in apple

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to the absence of knowledge of the distribution of Apple stem grooving virus (ASGV) and Apple chlorotic leaf spot virus (ACLSV) in apples in Korea, we carried out a survey for these viruses in Gyeongsang and Chungcheong provinces in 2014. A total of 65 samples were collected and tested by RT-PCR...

  9. Real-time RT-PCR for detection of Raspberry bushy dwarf virus, Raspberry leaf mottle virus and characterizing synergistic interactions in mixed infections

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two TaqMan-based real-time One-Step RT-PCR assays were developed for the rapid and efficient detection of Raspberry bushy dwarf virus (RBDV) and Raspberry leaf mottle virus (RLMV), two of the most common raspberry viruses in North America and Europe. The primers and probes were designed from conser...

  10. Quantification and Localization of Watermelon Chlorotic Stunt Virus and Tomato Yellow Leaf Curl Virus (Geminiviridae) in Populations of Bemisia tabaci (Hemiptera, Aleyrodidae) with Differential Virus Transmission Characteristics

    PubMed Central

    Kollenberg, Mario; Winter, Stephan; Götz, Monika

    2014-01-01

    Bemisia tabaci (Gennadius) is one of the economically most damaging insects to crops in tropical and subtropical regions. Severe damage is caused by feeding and more seriously by transmitting viruses. Those of the genus begomovirus (Geminiviridae) cause the most significant crop diseases and are transmitted by B. tabaci in a persistent circulative mode, a process which is largely unknown. To analyze the translocation and to identify critical determinants for transmission, two populations of B. tabaci MEAM1 were compared for transmitting Watermelon chlorotic stunt virus (WmCSV) and Tomato yellow leaf curl virus (TYLCV). Insect populations were chosen because of their high and respectively low virus transmission efficiency to compare uptake and translocation of virus through insects. Both populations harbored Rickettsia, Hamiltonella and Wolbachia in comparable ratios indicating that endosymbionts might not contribute to the different transmission rates. Quantification by qPCR revealed that WmCSV uptake and virus concentrations in midguts and primary salivary glands were generally higher than TYLCV due to higher virus contents of the source plants. Both viruses accumulated higher in insects from the efficiently compared to the poorly transmitting population. In the latter, virus translocation into the hemolymph was delayed and virus passage was impeded with limited numbers of viruses translocated. FISH analysis confirmed these results with similar virus distribution found in excised organs of both populations. No virus accumulation was found in the midgut lumen of the poor transmitter because of a restrained virus translocation. Results suggest that the poorly transmitting population comprised insects that lacked transmission competence. Those were selected to develop a population that lacks virus transmission. Investigations with insects lacking transmission showed that virus concentrations in midguts were reduced and only negligible virus amounts were found at the

  11. Interaction of tomato yellow leaf curl virus with diverse betasatellites enhances symptom severity.

    PubMed

    Ito, Takuya; Kimbara, Junji; Sharma, Pradeep; Ikegami, Masato

    2009-01-01

    The complete nucleotide sequence was determined for a begomovirus isolated from tomato exhibiting leaf curling and yellowing symptoms in Tochigi Prefecture in Japan. The genome organization of this virus was similar to those of other Old World monopartite begomoviruses. Neither a DNA betasatellite nor a DNA-B component was detected. It had the highest total nucleotide sequence identity (99%) with tomato yellow leaf curl virus-Israel[Japan:Tosa:2005] (TYLCV-IL[JR:Tos:05]) and TYLCV-Israel[Japan:Haruno:2005] (TYLCV-IL[JR:Han:05]). Its coat protein V1 also showed an identical amino acid sequence with those of TYLCV-IL[JR:Tos:05] and TYLCV-IL[JR:Han:05]. Thus, the begomovirus was determined to be an isolate of TYLCV-IL designated as TYLCV-Israel[Japan:Tochigi:2007] (TYLCV-IL[JR:Toc:07]). We investigated the interaction of TYLCV-IL[JR:Toc:07] with two known satellites associated with tomato yellow dwarf disease in Japan, tobacco leaf curl Japan betasatellite [Japan:Ibaraki:2006] and honeysuckle yellow vein mosaic betasatellite [Japan:Nara:2006], as well as with tomato leaf curl Philippines betasatellite [Philippines:Laguna1:2008], in tomato and Nicotiana benthamiana plants. TYLCV-IL[JR:Toc:07] trans-replicated these betasatellites, inducing more severe tomato yellow leaf curl disease-related symptoms than TYLCV-IL[JR:Toc:07] alone.

  12. A Rapid and Efficient Method for Construction of an Infectious Clone of Tomato yellow leaf curl virus.

    PubMed

    Bang, Bongjun; Lee, Jongyun; Kim, Sunyoung; Park, Jungwook; Nguyen, Thao Thi; Seo, Young-Su

    2014-09-01

    Tomato yellow leaf curl virus (TYLCV), a member of the genus Begomovirus, is responsible for one of the most devastating viral diseases in tomato-growing countries and is becoming a serious problem in many subtropical and tropical countries. The climate in Korea is getting warmer and developing subtropical features in response to global warming. These changes are being accompanied by TYLCV, which is now becoming a large problem in the Korean tomato industry. The most effective way to reduce damage caused by TYLCV is to breed resistant varieties of tomatoes. To accomplish this, it is necessary to establish a simple inoculation technique for the efficient evaluation of resistance to TYLCV. Here, we present the rolling circle amplification (RCA) method, which employs a bacteriophage using phi-29 DNA polymerase for construction of infectious TYLCV clones. The RCA method is simple, does not require sequence information for cloning, and is less expensive and time consuming than conventional PCR based-methods. Furthermore, RCA-based construction of an infectious clone can be very useful to other emerging and unknown geminiviruses in Korea.

  13. Characterization and occurrence of squash chlorotic leaf spot virus, a tentative new torradovirus infecting cucurbits in Sudan.

    PubMed

    Lecoq, H; Verdin, E; Tepfer, M; Wipf-Scheibel, C; Millot, P; Dafalla, G; Desbiez, C

    2016-06-01

    During a survey conducted in Sudan in 2012, a virus with spherical particles was isolated from a squash plant showing chlorotic leaf spots. The virus was transmitted mechanically and by two whitefly species, but not by aphids. RT-PCR with generic torradovirus primers yielded a band of expected size from total RNA of a symptomatic plant. Next-generation sequencing confirmed that this is tentatively a new torradovirus, for which we propose the name 'squash chlorotic leaf spot virus'. Using specific RT-PCR primers, the virus was detected in cucurbit samples collected since 1992 at different locations in Sudan.

  14. Transcript mapping of Cotton leaf curl Burewala virus and its cognate betasatellite, Cotton leaf curl Multan betasatellite

    PubMed Central

    2012-01-01

    Background Whitefly-transmitted geminiviruses (family Geminiviridae, genus Begomovirus) are major limiting factors for the production of numerous dicotyledonous crops throughout the warmer regions of the world. In the Old World a small number of begomoviruses have genomes consisting of two components whereas the majority have single-component genomes. Most of the monopartite begomoviruses associate with satellite DNA molecules, the most important of which are the betasatellites. Cotton leaf curl disease (CLCuD) is one of the major problems for cotton production on the Indian sub-continent. Across Pakistan, CLCuD is currently associated with a single begomovirus (Cotton leaf curl Burewala virus [CLCuBuV]) and the cotton-specific betasatellite Cotton leaf curl Multan betasatellite (CLCuMuB), both of which have recombinant origins. Surprisingly, CLCuBuV lacks C2, one of the genes present in all previously characterized begomoviruses. Virus-specific transcripts have only been mapped for few begomoviruses, including one monopartite begomovirus that does not associate with betasatellites. Similarly, the transcripts of only two betasatellites have been mapped so far. The study described has investigated whether the recombination/mutation events involved in the evolution of CLCuBuV and its associated CLCuMuB have affected their transcription strategies. Results The major transcripts of CLCuBuV and its associated betasatellite (CLCuMuB) from infected Nicotiana benthamiana plants have been determined. Two complementary-sense transcripts of ~1.7 and ~0.7 kb were identified for CLCuBuV. The ~1.7 kb transcript appears similar in position and size to that of several begomoviruses and likely directs the translation of C1 and C4 proteins. Both complementary-sense transcripts can potentially direct the translation of C2 and C3 proteins. A single virion-sense transcript of ~1 kb, suitable for translation of the V1 and V2 genes was identified. A predominant complementary

  15. Sequence characterization of tomato leaf curl Sinaloa virus and tomato severe leaf curl virus: phylogeny of New World begomoviruses and detection of recombination.

    PubMed

    Rojas, A; Kvarnheden, A; Marcenaro, D; Valkonen, J P T

    2005-07-01

    Diseases caused by begomoviruses (family Geminiviridae, genus Begomovirus) constitute a serious constraint to tomato production in Nicaragua. In this study, the complete nucleotide (nt) sequences of the DNA-A and DNA-B components were determined for the first time for Tomato leaf curl Sinaloa virus (ToLCSinV). In addition, the complete nt sequence was determined for the DNA-A component of two isolates of Tomato severe leaf curl virus (ToSLCV). The genome organization of ToLCSinV and ToSLCV was identical to the bipartite genomes of other begomoviruses described from the Americas. A phylogenetic analysis of DNA-A including 45 begomovirus species showed that the indigenous begomoviruses of the New World can be divided into three major clades and an intermediate group: AbMV clade, SLCV clade, "Brazil clade", and BGYMV group. Phylogenetic analyses of the DNA-A and DNA-B components and their open reading frames indicated that ToLCSinV and ToSLCV belong to different clades: ToLCSinV to the AbMV clade, and ToSLCV to the SLCV clade. The two Nicaraguan isolates of ToSLCV showed a close relationship with ToSLCV from Guatemala (ToSLCV-[GT96-1]) and Tomato chino La Paz virus (ToChLPV), but differed significantly in the AV1 and AC1 regions, respectively. Computer-based predictions indicated that recombination with another begomovirus had taken place within AV1 of ToSLCV dividing this species into two strains. A high probability was also found that ToChLPV is involved in the evolution of ToSLCV.

  16. Complete nucleotide sequence of rose yellow leaf virus, a new member of the family Tombusviridae.

    PubMed

    Mollov, Dimitre; Lockhart, Ben; Zlesak, David C

    2014-10-01

    The genome of the rose yellow leaf virus (RYLV) has been determined to be 3918 nucleotides long and to contain seven open reading frames (ORFs). ORF1 encodes a 27-kDa peptide (p27). ORF2 shares a common start codon with ORF1 and continues through the amber stop codon of p27 to encode an 87-kDa (p87) protein that has amino acid similarity to the RNA-dependent RNA polymerase (RdRp) of members of the family Tombusviridae. ORFs 3 and 4 have no significant amino acid similarity to known functional viral ORFs. ORF5 encodes a 6-kDa (p6) protein that has similarity to movement proteins of members of the Tombusviridae. ORF5A has no conventional start codon and overlaps with p6. A putative +1 frameshift mechanism allows p6 translation to continue through the stop codon and results in a 12-kDa protein that has high homology to the carmovirus p13 movement protein. The 37-kDa protein encoded by ORF6 has amino acid sequence similarity to coat proteins (CP) of members of the Tombusviridae. ORF7 has no significant amino acid similarity to known viral ORFs. Phylogenetic analysis of the RdRp amino acid sequences grouped RYLV together with the unclassified Rosa rugosa leaf distortion virus (RrLDV), pelargonium line pattern virus (PLPV), and pelargonium chlorotic ring pattern virus (PCRPV) in a distinct subgroup of the family Tombusviridae.

  17. Tomato yellow leaf curl virus: No evidence for replication in the insect vector Bemisia tabaci

    PubMed Central

    Sánchez-Campos, Sonia; Rodríguez-Negrete, Edgar A.; Cruzado, Lucía; Grande-Pérez, Ana; Bejarano, Eduardo R.; Navas-Castillo, Jesús; Moriones, Enrique

    2016-01-01

    Begomovirus ssDNA plant virus (family Geminiviridae) replication within the Bemisia tabaci vector is controversial. Transovarial transmission, alteration to whitefly biology, or detection of viral transcripts in the vector are proposed as indirect evidence of replication of tomato yellow leaf curl virus (TYLCV). Recently, contrasting direct evidence has been reported regarding the capacity of TYLCV to replicate within individuals of B. tabaci based on quantitave PCR approaches. Time-course experiments to quantify complementary and virion sense viral nucleic acid accumulation within B. tabaci using a recently implemented two step qPCR procedure revealed that viral DNA quantities did not increase for time points up to 96 hours after acquisition of the virus. Our findings do not support a recent report claiming TYLCV replication in individuals of B. tabaci. PMID:27476582

  18. Efficient Regeneration and Selection of Virus-free Sweetpotato Plants from Sweet Potato Leaf Curl Virus Infected Materials and Their Effects on Yields in Field Trials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sweet potato leaf curl virus (SPLCV) is an emerging virus disease in sweetpotato (Ipomoea batata) in the U.S. The incidence of SPLCV infection on sweetpotato increased dramatically in recent years due to the explosion of whitefly, Bemisia tabaci (Gennadius) populations. Among several sweetpotato v...

  19. Potential threat of a new pathotype of Papaya leaf distortion mosaic virus infecting transgenic papaya resistant to Papaya ringspot virus.

    PubMed

    Bau, H-J; Kung, Y-J; Raja, J A J; Chan, S-J; Chen, K-C; Chen, Y-K; Wu, H-W; Yeh, S-D

    2008-07-01

    A virus identified as a new pathotype of Papaya leaf distortion mosaic virus (PLDMV, P-TW-WF) was isolated from diseased papaya in an isolated test-field in central Taiwan, where transgenic papaya lines resistant to Papaya ringspot virus (PRSV) were evaluated. The infected plants displayed severe mosaic, distortion and shoe-stringing on leaves; stunting in apex; and water-soaking on petioles and stems. This virus, which did not react in enzyme-linked immunosorbent assay with the antiserum to the PRSV coat protein, infected only papaya, but not the other 18 plant species tested. Virions studied under electron microscope exhibited morphology and dimensions of potyvirus particles. Reverse transcription-polymerase chain reaction conducted using potyvirus-specific primers generated a 1,927-nucleotide product corresponding to the 3' region of a potyvirus, showing high sequence identity to the CP gene and 3' noncoding region of PLDMV. Search for similar isolates with the antiserum against CP of P-TW-WF revealed scattered occurrence of PLDMV in Taiwan. Phylogenetic analysis of PLDMV isolates of Taiwan and Japan indicated that the Taiwan isolates belong to a separate genetic cluster. Since all the Taiwan isolates infected only papaya, unlike the cucurbit-infecting Japanese P type isolates, the Taiwan isolates are considered a new pathotype of PLDMV. Susceptibility of all our PRSV-resistant transgenic papaya lines to PLDMV indicates that the virus is an emerging threat for the application of PRSV-resistant transgenic papaya in Taiwan and elsewhere.

  20. Natural Occurrence of Tomato leaf curl New Delhi virus in Iranian Cucurbit Crops

    PubMed Central

    Yazdani-Khameneh, Sara; Aboutorabi, Samaneh; Shoori, Majid; Aghazadeh, Azin; Jahanshahi, Parastoo; Golnaraghi, Alireza; Maleki, Mojdeh

    2016-01-01

    The main areas for field-grown vegetable production in Iran were surveyed during the years of 2012–2014 to determine the occurrence of begomoviruses infecting these crops. A total of 787 leaf samples were collected from vegetables and some other host plants showing virus-like symptoms and tested by an enzyme-linked immunosorbent assay (ELISA) using polyclonal antibodies produced against Tomato yellow leaf curl virus (TYLCV). According to the ELISA results, 81 samples (10.3%) positively reacted with the virus antibodies. Begomovirus infections were confirmed by polymerase chain reaction (PCR) using previously described TYLCV-specific primer pair TYLCV-Sar/TYLCV-Isr or universal primer pair Begomo-F/Begomo-R. The PCR tests using the primer pair TYLCV-Sar/TYLCV-Isr resulted in the amplification of the expected fragments of ca. 0.67-kb in size for ELISA-positive samples tested from alfalfa, pepper, spinach and tomato plants, confirming the presence of TYLCV. For one melon sample, having a week reaction in ELISA and no reaction in PCR using TYLCV-specific primers, the PCR reaction using the primer pair Begomo-F/Begomo-R resulted in the amplification fragments of the expected size of ca. 2.8 kb. The nucleotide sequences of the DNA amplicons derived from the isolate, Kz-Me198, were determined and compared with other sequences available in GenBank. BLASTN analysis confirmed the begomovirus infection of the sample and showed 99% identities with Tomato leaf curl New Delhi virus (ToLCNDV); phylogenetic analysis supported the results of the database searches. This study reports the natural occurrence of TYLCV in different hosts in Iran. Our results also reveal the emergence of ToLCNDV in Iranian cucurbit crops. PMID:27298595

  1. Detection of tomato yellow leaf curl Thailand virus by PCR without DNA extraction.

    PubMed

    Ieamkhang, Supaporn; Riangwong, Lumpueng; Chatchawankanphanich, Orawan

    2005-11-01

    We report the simple and rapid method for detection of tomato yellow leaf curl Thailand virus (TYLCTHV) based on the direct capture of virus particles to the surface of a polymerase chain reaction (PCR) tube. This method allowed PCR without the time-consuming procedures of DNA extraction from infected plant tissue. A small amount of tomato tissue (approximately 10 mg) was ground in extraction buffer to release viruses from plant tissues. The constituents of the plant extract that might inhibit PCR activity were discarded by washing the tube with PBST buffer before adding the PCR mixture to the tube. This method was used for detection of TYLCTHV with plant sap solution diluted up to 1:20,000 and was more sensitive than an enzyme-linked immunosorbent assay (ELISA) method. In addition, this method can be used for detection of TYLCTHV in viruliferous whiteflies. The PCR tubes with captured TYLCTHV could be used for PCR, after storage at 4 degrees C for 4 wk. The method presented here was used for detection of begomoviruses in cucurbit and pepper. In addition, this method was effectively used to detect papaya ringspot virus in papaya and zucchini yellow mosaic virus in cucumber by reverse transcriptase (RT)-PCR.

  2. The autophagy pathway participates in resistance to tomato yellow leaf curl virus infection in whiteflies.

    PubMed

    Wang, Lan-Lan; Wang, Xin-Ru; Wei, Xue-Mei; Huang, Huang; Wu, Jian-Xiang; Chen, Xue-Xin; Liu, Shu-Sheng; Wang, Xiao-Wei

    2016-09-01

    Macroautophagy/autophagy plays an important role against pathogen infection in mammals and plants. However, little has been known about the role of autophagy in the interactions of insect vectors with the plant viruses, which they transmit. Begomoviruses are a group of single-stranded DNA viruses and are exclusively transmitted by the whitefly Bemisia tabaci in a circulative manner. In this study, we found that the infection of a begomovirus, tomato yellow leaf curl virus (TYLCV) could activate the autophagy pathway in the Middle East Asia Minor 1 (MEAM1) species of the B. tabaci complex as evidenced by the formation of autophagosomes and ATG8-II. Interestingly, the activation of autophagy led to the subsequent degradation of TYLCV coat protein (CP) and genomic DNA. While feeding the whitefly with 2 autophagy inhibitors (3-methyladenine and bafilomycin A1) and silencing the expression of Atg3 and Atg9 increased the viral load; autophagy activation via feeding of rapamycin notably decreased the amount of viral CP and DNA in the whitefly. Furthermore, we found that activation of whitefly autophagy could inhibit the efficiency of virus transmission; whereas inhibiting autophagy facilitated virus transmission. Taken together, these results indicate that TYLCV infection can activate the whitefly autophagy pathway, which leads to the subsequent degradation of virus. Furthermore, our report proves that an insect vector uses autophagy as an intrinsic antiviral program to repress the infection of a circulative-transmitted plant virus. Our data also demonstrate that TYLCV may replicate and trigger complex interactions with the insect vector.

  3. A Novel Strain of Tomato Leaf Curl New Delhi Virus Has Spread to the Mediterranean Basin

    PubMed Central

    Fortes, Isabel M.; Sánchez-Campos, Sonia; Fiallo-Olivé, Elvira; Díaz-Pendón, Juan A.; Navas-Castillo, Jesús; Moriones, Enrique

    2016-01-01

    Tomato leaf curl New Delhi virus (ToLCNDV) is a whitefly-transmitted bipartite begomovirus (genus Begomovirus, family Geminiviridae) that causes damage to multiple cultivated plant species mainly belonging to the Solanaceae and Cucurbitaceae families. ToLCNDV was limited to Asian countries until 2012, when it was first reported in Spain, causing severe epidemics in cucurbit crops. Here, we show that a genetically-uniform ToLCNDV population is present in Spain, compatible with a recent introduction. Analyses of ToLCNDV isolates reported from other parts of the world indicated that this virus has a highly heterogeneous population genetically with no evident geographical, plant host or year-based phylogenetic groups observed. Isolates emerging in Spain belong to a strain that seems to have evolved by recombination. Isolates of this strain seem adapted to infecting cucurbits, but poorly infect tomatoes. PMID:27834936

  4. The begomoviruses Honeysuckle yellow vein mosaic virus and Tobacco leaf curl Japan virus with DNAbeta satellites cause yellow dwarf disease of tomato.

    PubMed

    Ogawa, T; Sharma, P; Ikegami, M

    2008-11-01

    The complete nucleotide sequences of two begomoviruses (Nara virus-1 and Nara virus-2), a satellite DNA (DNAbeta-Nara) and defective DNAs were obtained from honeysuckle (Lonicera japonica) showing characteristic yellow vein mosaic symptoms in Nara Prefecture, Japan. One begomovirus (Ibaraki virus) and a satellite DNA (DNAbeta-Ibaraki) was isolated and cloned from honeysuckle plants exhibited typical yellowing of veins and small elliptical shaped enations along veins on the under side of the leaves in Ibaraki Prefecture, Japan. The genome organization of the three viruses is the same as those of other Old World monopartite begomoviruses. Nara virus-1 had overall nucleotide sequence identity with Nara virus-2 of 94% and Ibaraki virus of 90%. DNAbeta-Nara had overall nucleotide sequence identity with DNAbeta-Ibaraki of 83%. Comparison of the nucleotide sequences with other begomoviruses revealed that Nara virus-1 and Nara virus-2 are strains of Honeysuckle yellow vein mosaic virus (HYVMV), hence named as HYVMV-Nara1 and HYVMV-Nara2, whereas Ibaraki virus was a strain of Tobacco leaf curl Japan virus (TbLCJV), designated as TbLCJV-Hs[Iba]. HYVMV-Nara1 and HYVMV-Nara2 have hybrid genomes, which are likely to have formed recombination between HYVMV and TbLCJV. TbLCJV-Hs[Iba] or HYVMV-Nara2 could infect and cause yellowing, leaf crinkling and stunting symptoms when partial tandem dimeric constructs were agroinoculated on tomato plants. However, in the presence of DNAbeta, both TbLCJV-Hs[Iba] or HYVMV-Nara2 produced more severe stunting symptoms in tomato plants. Therefore, these viruses along with their satellites are causal agents of tomato yellow dwarf disease in Japan, and honeysuckle acts as a potential reservoir host. Previously available evidence indicated that DNAbeta elements do not contain iteron sequences of their helper viruses; hence this is the first evidence that DNAbeta satellites have the iteron of their helper virus.

  5. A new betasatellite associated with cotton leaf curl Burewala virus infecting tomato in India: influence on symptoms and viral accumulation.

    PubMed

    Kumar, Jitendra; Gunapati, Samatha; Singh, Sudhir P; Kumar, Abhinav; Lalit, Adarsh; Sharma, Naresh C; Puranik, Rekha; Tuli, Rakesh

    2013-06-01

    A begomovirus and its associated alpha- and betasatellite were detected in tomato plants affected with leaf curl disease. Based on a nucleotide sequence identity of 99 %, this begomovirus was designated an isolate of cotton leaf curl Burewala virus (CLCuBuV). The alphasatellite exhibited 93 % sequence identity to cotton leaf curl Burewala alphasatellite (CLCuBuA) and is hence referred to here as a variant of CLCuBuA. The detected betasatellite was recombinant in nature and showed 70 % sequence identity to the known betasatellites. Inoculation of healthy tomato with CLCuBuV plus betasatellite, either in the presence or the absence of alphasatellite, led to typical leaf curling, while inoculation with CLCuBuV in the absence of betasatellite resulted in mild symptoms. This confirmed the role of the betasatellite in expression of disease symptoms. We propose to name the newly detected betasatellite tomato leaf curl Hajipur betasatellite (ToLCHJB).

  6. The Involvement of Heat Shock Proteins in the Establishment of Tomato Yellow Leaf Curl Virus Infection

    PubMed Central

    Gorovits, Rena; Czosnek, Henryk

    2017-01-01

    Tomato yellow leaf curl virus (TYLCV), a begomovirus, induces protein aggregation in infected tomatoes and in its whitefly vector Bemisia tabaci. The interactions between TYLCV and HSP70 and HSP90 in plants and vectors are necessity for virus infection to proceed. In infected host cells, HSP70 and HSP90 are redistributed from a soluble to an aggregated state. These aggregates contain, together with viral DNA/proteins and virions, HSPs and components of the protein quality control system such as ubiquitin, 26S proteasome subunits, and the autophagy protein ATG8. TYLCV CP can form complexes with HSPs in tomato and whitefly. Nonetheless, HSP70 and HSP90 play different roles in the viral cell cycle in the plant host. In the infected host cell, HSP70, but not HSP90, participates in the translocation of CP from the cytoplasm into the nucleus. Viral amounts decrease when HSP70 is inhibited, but increase when HSP90 is downregulated. In the whitefly vector, HSP70 impairs the circulative transmission of TYLCV; its inhibition increases transmission. Hence, the efficiency of virus acquisition by whiteflies depends on the functionality of both plant chaperones and their cross-talk with other protein mechanisms controlling virus-induced aggregation. PMID:28360921

  7. Characterization of Cestrum yellow leaf curling virus: a new member of the family Caulimoviridae.

    PubMed

    Stavolone, Livia; Ragozzino, Antonio; Hohn, Thomas

    2003-12-01

    Cestrum yellow leaf curling virus (CmYLCV) has been characterized as the aetiological agent of the Cestrum parqui mosaic disease. The virus genome was cloned and the clone was proven to be infectious to C. parqui. The presence of typical viroplasms in virus-infected plant tissue and the information obtained from the complete genomic sequence confirmed CmYLCV as a member of the Caulimoviridae family. All characteristic domains conserved in plant pararetroviruses were found in CmYLCV. Its genome is 8253 bp long and contains seven open reading frames (ORFs). Phylogenetic analysis of the relationships with other members of the Caulimoviridae revealed that CmYLCV is closely related to the Soybean chlorotic mottle virus (SbCMV)-like genus and particularly to SbCMV. However, in contrast to the other members of this genus, the primer-binding site is located in the intercistronic region following ORF Ib rather than within this ORF, and an ORF corresponding to ORF VII is missing.

  8. Molecular characterization and infectivity of Papaya leaf curl China virus infecting tomato in China.

    PubMed

    Zhang, Hui; Ma, Xin-ying; Qian, Ya-juan; Zhou, Xue-ping

    2010-02-01

    Papaya leaf curl China virus (PaLCuCNV) was previously reported as a distinct begomovirus infecting papaya in southern China. Based on molecular diagnostic survey, 13 PaLCuCNV isolates were obtained from tomato plants showing leaf curl symptoms in Henan and Guangxi Provinces of China. Complete nucleotide sequences of 5 representative isolates (AJ558116, AJ558117, AJ704604, FN256260, and FN297834) were determined to be 2738-2751 nucleotides, which share 91.7%-97.9% sequence identities with PaLCuCNV isolate G2 (AJ558123). DNA-beta was not found to be associated with PaLCuCNV isolates. To investigate the infectivity of PaLCuCNV, an infectious clone of PaLCuCNV-[CN:HeNZM1] was constructed and agro-inoculated into Nicotiana benthamiana, N. tabacum Samsun, N. glutinosa, Solanum lycopersicum and Petunia hybrida plants, which induced severe leaf curling and crinkling symptoms in these plants. Southern blot analysis and polymerase chain reaction (PCR) indicated a systemic infection of test plants by the agro-infectious clone.

  9. Generation of transgenic papaya with double resistance to Papaya ringspot virus and Papaya leaf-distortion mosaic virus.

    PubMed

    Kung, Yi-Jung; Bau, Huey-Jiunn; Wu, Yi-Ling; Huang, Chiung-Huei; Chen, Tsui-Miao; Yeh, Shyi-Dong

    2009-11-01

    During the field tests of coat protein (CP)-transgenic papaya lines resistant to Papaya ringspot virus (PRSV), another Potyvirus sp., Papaya leaf-distortion mosaic virus (PLDMV), appeared as an emerging threat to the transgenic papaya. In this investigation, an untranslatable chimeric construct containing the truncated CP coding region of the PLDMV P-TW-WF isolate and the truncated CP coding region with the complete 3' untranslated region of PRSV YK isolate was transferred into papaya (Carica papaya cv. Thailand) via Agrobacterium-mediated transformation to generate transgenic plants with resistance to PLDMV and PRSV. Seventy-five transgenic lines were obtained and challenged with PRSV YK or PLDMV P-TW-WF by mechanical inoculation under greenhouse conditions. Thirty-eight transgenic lines showing no symptoms 1 month after inoculation were regarded as highly resistant lines. Southern and Northern analyses revealed that four weakly resistant lines have one or two inserts of the construct and accumulate detectable amounts of transgene transcript, whereas nine resistant lines contain two or three inserts without significant accumulation of transgene transcript. The results indicated that double virus resistance in transgenic lines resulted from double or more copies of the insert through the mechanism of RNA-mediated posttranscriptional gene silencing. Furthermore, three of nine resistant lines showed high levels of resistance to heterologous PRSV strains originating from Hawaii, Thailand, and Mexico. Our transgenic lines have great potential for controlling a number of PRSV strains and PLDMV in Taiwan and elsewhere.

  10. Melon chlorotic leaf curl virus: characterization and differential reassortment with closest relatives reveal adaptive virulence in the squash leaf curl virus clade and host shifting by the host-restricted bean calico mosaic virus.

    PubMed

    Idris, A M; Mills-Lujan, K; Martin, K; Brown, J K

    2008-02-01

    The genome components of the Melon chlorotic leaf curl virus (MCLCuV) were cloned from symptomatic cantaloupe leaves collected in Guatemala during 2002. The MCLCuV DNA-A and DNA-B components shared their closest nucleotide identities among begomoviruses, at approximately 90 and 81%, respectively, with a papaya isolate of MCLCuV from Costa Rica. The closest relatives at the species level were other members of the Squash leaf curl virus (SLCV) clade, which is endemic in the southwestern United States and Mexico. Biolistic inoculation of cantaloupe seedlings with the MCLCuV DNA-A and -B components resulted in the development of characteristic disease symptoms, providing definitive evidence of causality. MCLCuV experimentally infected species within the Cucurbitaceae, Fabaceae, and Solanaceae. The potential for interspecific reassortment was examined for MCLCuV and its closest relatives, including the bean-restricted Bean calico mosaic virus (BCaMV), and three other cucurbit-infecting species, Cucurbit leaf crumple virus (CuLCrV), SLCV, and SMLCV. The cucurbit viruses have distinct but overlapping host ranges. All possible reassortants were established using heterologous combinations of the DNA-A or DNA-B components. Surprisingly, only certain reassortants arising from MCLCuV and BCaMV, or MCLCuV and CuLCrV, were viable in bean, even though it is a host of all of the "wild-type" (parent) viruses. The bean-restricted BCaMV was differentially assisted in systemically infecting the cucurbit test species by the components of the four cucurbit-adapted begomoviruses. In certain heterologous combinations, the BCaMV DNA-A or -B component was able to infect one or more cucurbit species. Generally, the reassortants were less virulent in the test hosts than the respective wild-type (parent) viruses, strongly implicating adaptive modulation of virulence. This is the first illustration of reassortment resulting in the host range expansion of a host-restricted begomovirus.

  11. Molecular Evidence for Occurrence of Tomato leaf curl New Delhi virus in Ash Gourd (Benincasa hispida) Germplasm Showing a Severe Yellow Stunt Disease in India.

    PubMed

    Roy, Anirban; Spoorthi, P; Panwar, G; Bag, Manas Kumar; Prasad, T V; Kumar, Gunjeet; Gangopadhyay, K K; Dutta, M

    2013-06-01

    An evaluation of 70 accessions of ash gourd germplasm grown at National Bureau of Plant Genetic Resources, New Delhi, India during Kharif season (2010) showed natural occurrence of a yellow stunt disease in three accessions (IC554690, IC036330 and Pusa Ujjwal). A set of begomovirus specific primers used in PCR gave expected amplicon from all the symptomatic plants; however no betasatellite was detected. Complete genome of the begomovirus (DNA-A and DNA-B), amplified through rolling circle amplification, was cloned and sequenced. The begomovirus under study shared high sequence identities to different isolates of Tomato leaf curl New Delhi virus (ToLCNDV) and clustered with them. Among those isolates, the DNA-A and DNA-B of the present begomovirus isolate showed highest 99.6 and 96.8 % sequence identities, respectively with an isolate reported on pumpkin from India (DNA-A: AM286433, DNA-B: AM286435). Based on the sequence analysis, the begomovirus obtained from ash gourd was considered as an isolate of ToLCNDV. Thus, the present findings constitute the first report of occurrence of a new yellow stunt disease in ash gourd from India and demonstrated the association of ToLCNDV with the symptomatic samples. Occurrence of ToLCNDV in ash gourd germplasm not only adds up a new cucurbitaceous host of this virus but also raises the concern about the perpetuation of this virus in absence of its main host tomato and thus has an epidemiological relevance for understanding the rapid spread of this virus in tomato and other hosts in Indian sub-continent.

  12. Molecular analysis of new isolates of Tomato leaf curl Philippines virus and an associated betasatellite occurring in the Philippines.

    PubMed

    Sharma, Pradeep; Matsuda, N; Bajet, N B; Ikegami, M

    2011-02-01

    Three new begomovirus isolates and one betasatellite were obtained from a tomato plant exhibiting leaf curl symptom in Laguna, the Philippines. Typical begomovirus DNA components representing the three isolates (PH01, PH02 and PH03) were cloned, and their full-length sequences were determined to be 2754 to 2746 nucleotides. The genome organizations of these isolates were similar to those of other Old World monopartite begomoviruses. The sequence data indicated that PH01 and PH02 were variants of strain B of the species Tomato leaf curl Philippines virus, while PH03 was a variant of strain A of the species Tomato leaf curl Philippines virus. These isolates were designated ToLCPV-B[PH:Lag1:06], ToLCPV-B[PH:Lag2:06], and ToLCPV-A[PH:Lag3:06], respectively. Phylogenetic analysis revealed that the present isolates form a separate monophyletic cluster with indigenous begomoviruses reported earlier in the Philippines. A betasatellite isolated from same sample belongs to the betasatellite species Tomato leaf curl Philippines betasatellite and designated Tomato leaf curl Philippines betasatellite-[Philippines:Laguna1:2006], ToLCPHB-[PH:Lag1:06]. When co-inoculated with this betasatellite, tomato leaf curl Philippines virus induced severe symptoms in N. benthamiana and Solanum lycopersicum plants. Using a PVX-mediated transient assay, we found that the C4 and C2 proteins of tomato leaf curl Philippines virus and the βC1 protein of ToLCPHB-[PH:Lag1:06] function as a suppressor of RNA silencing.

  13. The Complete Nucleotide Sequence and Biotype Variability of Papaya leaf distortion mosaic virus.

    PubMed

    Maoka, Tetsuo; Hataya, Tatsuji

    2005-02-01

    ABSTRACT The complete nucleotide sequence of the genome of Papaya leaf distortion mosaic virus (PLDMV) was determined. The viral RNA genome of strain LDM (leaf distortion mosaic) comprised 10,153 nucleotides, excluding the poly(A) tail, and contained one long open reading frame encoding a polyprotein of 3,269 amino acids (molecular weight 373,347). The polyprotein contained nine putative proteolytic cleavage sites and some motifs conserved in other potyviral polyproteins with 44 to 50% identities, indicating that PLDMV is a distinct species in the genus Potyvirus. Like the W biotype of Papaya ringspot virus (PRSV), the non-papaya-infecting biotype of PLDMV (PLDMV-C) was found in plants of the family Cucurbitaceae. The coat protein (CP) sequence of PLDMV-C in naturally infected-Trichosanthes bracteata was compared with those of three strains of the P biotype (PLDMV-P), LDM and two additional strains M (mosaic) and YM (yellow mosaic), which are biologically different from each other. The CP sequences of three strains of PLDMV-P share high identities of 95 to 97%, while they share lower identities of 88 to 89% with that of PLDMV-C. Significant changes in hydrophobicity and a deletion of two amino acids at the N-terminal region of the CP of PLDMV-C were observed. The finding of two biotypes of PLDMV implies the possibility that the papaya-infecting biotype evolved from the cucurbitaceae-infecting potyvirus, as has been previously suggested for PRSV. In addition, a similar evolutionary event acquiring infectivity to papaya may arise frequently in viruses in the family Cucurbitaceae.

  14. Molecular phylogenetics and evolution of host plant use in the Neotropical rolled leaf 'hispine' beetle genus Cephaloleia (Chevrolat) (Chrysomelidae: Cassidinae).

    PubMed

    McKenna, Duane D; Farrell, Brian D

    2005-10-01

    Here, we report the results of a species level phylogenetic study of Cephaloleia beetles designed to clarify relationships and patterns of host plant taxon and tissue use among species. Our study is based on up to 2088bp of mtDNA sequence data. Maximum parsimony, maximum likelihood, and Bayesian methods of phylogenetic inference consistently recover a monophyletic Cephaloleia outside of a basal clade of primarily palm feeding species (the 'Arecaceae-feeding clade'), and C. irregularis. In all three analyses, the 'Arecaceae-feeding clade' includes Cephaloleia spp. with unusual morphological features, and a few species currently placed in other cassidine genera and tribes. All three analyses also recover a clade that includes all Zingiberales feeding Cephaloleia and most Cephaloleia species (the 'Zingiberales-feeding clade'). Two notable clades are found within the 'Zingiberales-feeding clade.' One is comprised of beetles that normally feed only on the young rolled leaves of plants in the families Heliconiaceae and Marantaceae (the 'Heliconiaceae & Marantaceae-feeding clade'). The other is comprised of relative host tissue generalist, primarily Zingiberales feeding species (the 'generalist-feeding clade'). A few species in the 'generalist-feeding clade' utilize Cyperaceae or Poaceae as hosts. Overall, relatively basal Cephaloleia (e.g., the 'Arecaceae clade') feed on relatively basal monocots (e.g., Cyclanthaceae and Arecaceae), and relatively derived Cephaloleia (e.g., the 'Zingiberales-feeding clade') feed on relatively derived monocots (mostly in the order Zingiberales). Zingiberales feeding and specialization on young rolled Zingiberales leaves have each apparently evolved just once in Cephaloleia.

  15. Association of an Alphasatellite with Tomato Yellow Leaf Curl Virus and Ageratum Yellow Vein Virus in Japan is Suggestive of a Recent Introduction

    PubMed Central

    Shahid, Muhammad Shafiq; Ikegami, Masato; Waheed, Abdul; Briddon, Rob W.; Natsuaki, Keiko T.

    2014-01-01

    Samples were collected in 2011 from tomato plants exhibiting typical tomato leaf curl disease symptoms in the vicinity of Komae, Japan. PCR mediated amplification, cloning and sequencing of all begomovirus components from two plants from different fields showed the plants to be infected by Tomato yellow leaf curl virus (TYLCV) and Ageratum yellow vein virus (AYVV). Both viruses have previously been shown to be present in Japan, although this is the first identification of AYVV on mainland Japan; the virus previously having been shown to be present on the Okinawa Islands. The plant harboring AYVV was also shown to contain the betasatellite Tomato leaf curl Java betasatellite (ToLCJaB), a satellite not previously shown to be present in Japan. No betasatellite was associated with the TYLCV infected tomato plants analyzed here, consistent with earlier findings for this virus in Japan. Surprisingly both plants were also found to harbor an alphasatellite; no alphasatellites having previously been reported from Japan. The alphasatellite associated with both viruses was shown to be Sida yellow vein China alphasatellite which has previously only been identified in the Yunnan Province of China and Nepal. The results suggest that further begomoviruses, and their associated satellites, are being introduced to Japan. The significance of these findings is discussed. PMID:24424499

  16. Association of an alphasatellite with tomato yellow leaf curl virus and ageratum yellow vein virus in Japan is suggestive of a recent introduction.

    PubMed

    Shahid, Muhammad Shafiq; Ikegami, Masato; Waheed, Abdul; Briddon, Rob W; Natsuaki, Keiko T

    2014-01-14

    Samples were collected in 2011 from tomato plants exhibiting typical tomato leaf curl disease symptoms in the vicinity of Komae, Japan. PCR mediated amplification, cloning and sequencing of all begomovirus components from two plants from different fields showed the plants to be infected by Tomato yellow leaf curl virus (TYLCV) and Ageratum yellow vein virus (AYVV). Both viruses have previously been shown to be present in Japan, although this is the first identification of AYVV on mainland Japan; the virus previously having been shown to be present on the Okinawa Islands. The plant harboring AYVV was also shown to contain the betasatellite Tomato leaf curl Java betasatellite (ToLCJaB), a satellite not previously shown to be present in Japan. No betasatellite was associated with the TYLCV infected tomato plants analyzed here, consistent with earlier findings for this virus in Japan. Surprisingly both plants were also found to harbor an alphasatellite; no alphasatellites having previously been reported from Japan. The alphasatellite associated with both viruses was shown to be Sida yellow vein China alphasatellite which has previously only been identified in the Yunnan Province of China and Nepal. The results suggest that further begomoviruses, and their associated satellites, are being introduced to Japan. The significance of these findings is discussed.

  17. Female-Biased Symbionts and Tomato Yellow Leaf Curl Virus Infections in Bemisia tabaci

    PubMed Central

    Guo, Huifang; Qu, Yufeng; Liu, Xiangdong; Zhong, Wanfang; Fang, Jichao

    2014-01-01

    The female-biased infection of facultative symbionts has been found in Bemisia tabaci; however, whether there are any differences in tomato yellow leaf curl virus (TYLCV) and obligate symbiont infection rates between females and males is unknown. Determining whether such differences exist would be very important for understanding the spread of the plant virus and of the symbionts. We compared both symbiont infection types, including obligate and facultative symbionts, and the rates of TYLCV infection in both sexes in five field populations from Jiangsu Province, China. The obligate symbiont Portiera aleyrodidarum was not found in every whitefly tested. In all tested populations, more females than males were found to harbor P. aleyrodidarum; and more females than males also harbored Hamiltonella defense, the most common facultative symbiont as well as Cardinium. In addition to female-biased symbiont infections, there were also female-biased TYLCV infections, and the infection frequencies of this plant virus in females were higher than those in males. Taken together, these results suggested that both the female-biased symbiont infections and female-biased TYLCV infections promoted the rapid spread of TYLCV in China. PMID:24465416

  18. Tomato yellow leaf curl virus (TYLCV-IL): a seed-transmissible geminivirus in tomatoes.

    PubMed

    Kil, Eui-Joon; Kim, Sunhoo; Lee, Ye-Ji; Byun, Hee-Seong; Park, Jungho; Seo, Haneul; Kim, Chang-Seok; Shim, Jae-Kyoung; Lee, Jung-Hwan; Kim, Ji-Kwang; Lee, Kyeong-Yeoll; Choi, Hong-Soo; Lee, Sukchan

    2016-01-08

    Tomato yellow leaf curl virus (TYLCV) is one of the most well-known tomato-infecting begomoviruses and transmitted by Bemisia tabaci. Seed transmission has previously been reported for some RNA viruses, but TYLCV has not previously been described as a seed-borne virus. In 2013 and 2014, without whitefly-mediated transmission, TYLCV was detected in young tomato plants germinated from fallen fruits produced from TYLCV-infected tomato plants in the previous cultivation season. In addition, TYLCV-Israel (TYLCV-IL) was also detected in seeds and their seedlings of TYLCV-infected tomato plants that were infected by both viruliferous whitefly-mediated transmission and agro-inoculation. The seed infectivity was 20-100%, respectively, and the average transmission rate to seedlings was also 84.62% and 80.77%, respectively. TYLCV-tolerant tomatoes also produced TYLCV-infected seeds, but the amount of viral genome was less than seen in TYLCV-susceptible tomato plants. When tomato plants germinated from TYLCV-infected seeds, non-viruliferous whiteflies and healthy tomato plants were placed in an insect cage together, TYLCV was detected from whiteflies as well as receiver tomato plants six weeks later. Taken together, TYLCV-IL can be transmitted via seeds, and tomato plants germinated from TYLCV-infected seeds can be an inoculum source of TYLCV. This is the first report about TYLCV seed transmission in tomato.

  19. Detection of Papaya leaf distortion mosaic virus by reverse-transcription loop-mediated isothermal amplification.

    PubMed

    Shen, Wentao; Tuo, Decai; Yan, Pu; Li, Xiaoying; Zhou, Peng

    2014-01-01

    Papaya leaf distortion mosaic virus (PLDMV) can infect transgenic papaya resistant to a related pathogen, Papaya ringspot virus (PRSV), posing a substantial threat to papaya production in China. Current detection methods, however, are unable to be used for rapid detection in the field. Here, a reverse-transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for the detection of PLDMV, using a set of four RT-LAMP primers designed based on the conserved sequence of PLDMV CP. The RT-LAMP method detected specifically PLDMV and was highly sensitive, with a detection limit of 1.32×10(-6) μg of total RNA per reaction. Indeed, the reaction was 10 times more sensitive than one-step RT-PCR, while also requiring significantly less time and equipment. The effectiveness of RT-LAMP and one-step RT-PCR in detecting the virus were compared using 90 field samples of non-transgenic papaya and 90 field samples of commercialized PRSV-resistant transgenic papaya from Hainan Island. None of the non-transgenic papaya tested positive for PLDMV using either method. In contrast, 19 of the commercialized PRSV-resistant transgenic papaya samples tested positive by RT-LAMP assay, and 6 of those tested negative by RT-PCR. Therefore, the PLDMV-specific RT-LAMP is a simple, rapid, sensitive, and cost-effective tool in the field diagnosis and control of PLDMV.

  20. Identification of differentially expressed genes in tomato associated with R-lines Ty-5 against tomato yellow leaf curl virus (TYLCV) and Sw-7 against tomato spotted wilt virus (TSWV)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tomato yellow leaf curl virus (TYLCV) and tomato spotted wilt virus (TSWV) are two most economically important viruses affecting tomato productions worldwide. Developing a cultivar with resistance to these viruses would be the most effective and economical means of disease management. Comparative ...

  1. Implications Of Host Plant Resistance Against Whitefly-Transmitted Tomato Yellow Leaf Curl Virus In Tomato For Virus Epidemics And Management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whitefly-transmitted Tomato yellow leaf curl virus (TYLCV) severely impacts tomato production in southeastern USA. Growers typically spray insecticides against whiteflies and plant TYLCV-resistant genotypes. Semi-dominant genes such as TY-1 and TY-2 confer resistance to TYLCV. Resistant genotypes ar...

  2. Tomato leaf curl New Delhi virus: a widespread bipartite begomovirus in the territory of monopartite begomoviruses.

    PubMed

    Zaidi, Syed Shan-E-Ali; Martin, Darren P; Amin, Imran; Farooq, Muhammad; Mansoor, Shahid

    2016-08-23

    Tomato leaf curl New Delhi virus (ToLCNDV) is an exceptional Old World bipartite begomovirus. On the Indian subcontinent, a region in which monopartite DNA satellite-associated begomoviruses with mostly narrow geographical ranges predominate, it is widespread, with a geographical range also including the Far East, Middle East, North Africa and Europe. The success of ToLCNDV probably derives from its broad host range and highly flexible genomic configuration: its DNA-A component is capable of productively interacting with, and trans-replicating, diverse DNA-B components and betasatellites. An understanding of the capacity of ToLCNDV to infect a variety of hosts and spread across a broad and ecologically variable geographical range could illuminate the potential economic threats associated with similar begomoviral invasions. Towards this end, we used available ToLCNDV sequences to reconstruct the history of ToLCNDV spread.

  3. Lamium amplexicaule (Lamiaceae): a weed reservoir for tomato yellow leaf curl virus (TYLCV) in Korea.

    PubMed

    Kil, Eui-Joon; Park, Jungan; Lee, Hyejung; Kim, Jaedeok; Choi, Hong-Soo; Lee, Kyeong-Yeoll; Kim, Chang-Seok; Lee, Sukchan

    2014-06-01

    After the first identification of tomato yellow leaf curl virus (TYLCV) in the southern part of Korea in 2008, TYLCV has rapidly spread to tomato farms in most regions of Korea. From 2008 to 2010, a survey of natural weed hosts that could be reservoirs of TYLCV was performed in major tomato production areas of Korea. About 530 samples were collected and identified as belonging to 25 species from 11 families. PCR and Southern hybridization were used to detect TYLCV in samples, and replicating forms of TYLCV DNA were detected in three species (Achyranthes bidentata, Lamium amplexicaule, and Veronica persica) by Southern hybridization. TYLCV transmission mediated by Bemisia tabaci from TYLCV-infected tomato plants to L. amplexicaule was confirmed, and TYLCV-infected L. amplexicaule showed symptoms such as yellowing, stunting, and leaf curling. TYLCV from infected L. amplexicaule was also transmitted to healthy tomato and L. amplexicaule plants by B. tabaci. The rate of infection of L. amplexicaule by TYLCV was similar to that of tomato. This report is the first to show that L. amplexicaule is a reservoir weed host for TYLCV.

  4. Genetic diversity, host range, and distribution of tomato yellow leaf curl virus in Iran.

    PubMed

    Shirazi, M; Mozafari, J; Rakhshandehroo, F; Shams-Bakhsh, M

    2014-01-01

    Tomato yellow leaf curl virus (TYLCV) is considered one of the most important tomato pathogens in tropical and subtropical regions including Iran. During the years 2007 to 2009, a total number of 510 symptomatic and asymptomatic vegetable, ornamental and weed samples were collected from fields and greenhouses in ten provinces of Iran. Symptoms included stunting, yellowing, leaf curl and flower senescence. PCR with specific primers showed TYLCV infection in 184 samples (36%) such as cucumber, pepper, tomato and several weeds from seven provinces. Based on the geographical origin, host range and symptoms, twenty three representative isolates were selected for phylogenetic analysis. An amplicon with a size about 608 base pair (bp) comprising partial sequence of the coat (CP) and movement protein (MP) coding regions of the viral genome was sequenced and compared with the corresponding selected sequences available in GenBank for Iran and worldwide. Phylogenetic analyses on the basis of the nucleotide sequences indicated two geographically separated clades. Isolates collected from Hormozgan, Khuzestan and Kerman provinces were grouped together with other Iranian isolates including TYLCV-Ir2, TYLCV-Kahnooj, and an isolate from Oman. It was also revealed that isolates collected from Boushehr, Fars, Tehran, and Isfahan placed close to the Iranian isolate TYLCV-Abadeh and isolates from Israel and Egypt. No correlation was found between the genetic variation and the host species, but selected Iranian isolates were grouped on the basis of the geographical origins. Results of this study indicated a high genetic diversity among Iranian TYLCV isolates.

  5. Recessive Resistance Derived from Tomato cv. Tyking-Limits Drastically the Spread of Tomato Yellow Leaf Curl Virus

    PubMed Central

    Pereira-Carvalho, Rita C.; Díaz-Pendón, Juan A.; Fonseca, Maria Esther N.; Boiteux, Leonardo S.; Fernández-Muñoz, Rafael; Moriones, Enrique; Resende, Renato O.

    2015-01-01

    The tomato yellow leaf curl disease (TYLCD) causes severe damage to tomato (Solanum lycopersicum L.) crops throughout tropical and subtropical regions of the world. TYLCD is associated with a complex of single-stranded circular DNA plant viruses of the genus Begomovirus (family Geminiviridae) transmitted by the whitefy Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae). The tomato inbred line TX 468-RG is a source of monogenic recessive resistance to begomoviruses derived from the hybrid cv. Tyking F1. A detailed analysis of this germplasm source against tomato yellow leaf curl virus-Israel (TYLCV-IL), a widespread TYLCD-associated virus, showed a significant restriction to systemic virus accumulation even under continuous virus supply. The resistance was effective in limiting the onset of TYLCV-IL in tomato, as significantly lower primary spread of the virus occurred in resistant plants. Also, even if a limited number of resistant plants could result infected, they were less efficient virus sources for secondary spread owing to the impaired TYLCV-IL accumulation. Therefore, the incorporation of this resistance into breeding programs might help TYLCD management by drastically limiting TYLCV-IL spread. PMID:26008699

  6. Leaf rolling and stem fasciation in grass pea (Lathyrus sativus L.) mutant are mediated through glutathione-dependent cellular and metabolic changes and associated with a metabolic diversion through cysteine during phenotypic reversal.

    PubMed

    Talukdar, Dibyendu; Talukdar, Tulika

    2014-01-01

    A Lathyrus sativus L. mutant isolated in ethylmethane sulfonate-treated M2 progeny of mother variety BioL-212 and designated as rlfL-1 was characterized by inwardly rolled-leaf and stem and bud fasciations. The mutant exhibited karyomorphological peculiarities in both mitosis and meiosis with origin of aneuploidy. The mitosis was vigorous with high frequency of divisional cells and their quick turnover presumably steered cell proliferations. Significant transcriptional upregulations of cysteine and glutathione synthesis and concomitant stimulations of glutathione-mediated antioxidant defense helped rlfL-1 mutant to maintain balanced reactive oxygen species (ROS) metabolisms, as deduced by ROS-imaging study. Glutathione synthesis was shut down in buthionine sulfoximine- (BSO-) treated mother plant and mutant, and leaf-rolling and stems/buds fasciations in the mutant were reversed, accompanied by normalization of mitotic cell division process. Antioxidant defense was downregulated under low glutathione-redox but cysteine-desulfurations and photorespiratory glycolate oxidase transcripts were markedly overexpressed, preventing cysteine overaccumulation but resulted in excess H2O2 in BSO-treated mutant. This led to oxidative damage in proliferating cells, manifested by severe necrosis in rolled-leaf and fasciated stems. Results indicated vital role of glutathione in maintaining abnormal proliferations in plant organs, and its deficiency triggered phenotypic reversal through metabolic diversions of cysteine and concomitant cellular and metabolic modulations.

  7. Leaf Rolling and Stem Fasciation in Grass Pea (Lathyrus sativus L.) Mutant Are Mediated through Glutathione-Dependent Cellular and Metabolic Changes and Associated with a Metabolic Diversion through Cysteine during Phenotypic Reversal

    PubMed Central

    Talukdar, Dibyendu; Talukdar, Tulika

    2014-01-01

    A Lathyrus sativus L. mutant isolated in ethylmethane sulfonate-treated M2 progeny of mother variety BioL-212 and designated as rlfL-1 was characterized by inwardly rolled-leaf and stem and bud fasciations. The mutant exhibited karyomorphological peculiarities in both mitosis and meiosis with origin of aneuploidy. The mitosis was vigorous with high frequency of divisional cells and their quick turnover presumably steered cell proliferations. Significant transcriptional upregulations of cysteine and glutathione synthesis and concomitant stimulations of glutathione-mediated antioxidant defense helped rlfL-1 mutant to maintain balanced reactive oxygen species (ROS) metabolisms, as deduced by ROS-imaging study. Glutathione synthesis was shut down in buthionine sulfoximine- (BSO-) treated mother plant and mutant, and leaf-rolling and stems/buds fasciations in the mutant were reversed, accompanied by normalization of mitotic cell division process. Antioxidant defense was downregulated under low glutathione-redox but cysteine-desulfurations and photorespiratory glycolate oxidase transcripts were markedly overexpressed, preventing cysteine overaccumulation but resulted in excess H2O2 in BSO-treated mutant. This led to oxidative damage in proliferating cells, manifested by severe necrosis in rolled-leaf and fasciated stems. Results indicated vital role of glutathione in maintaining abnormal proliferations in plant organs, and its deficiency triggered phenotypic reversal through metabolic diversions of cysteine and concomitant cellular and metabolic modulations. PMID:24987684

  8. Conservation of major and minor jelly-roll capsid proteins in Polinton (Maverick) transposons suggests that they are bona fide viruses

    PubMed Central

    2014-01-01

    Reviewers This article was reviewed by Lakshminarayan M. Iyer and I. King Jordan. For complete reviews, see the Reviewers’ Reports section. Polintons (also known as Mavericks) and Tlr elements of Tetrahymena thermophila represent two families of large DNA transposons widespread in eukaryotes. Here, we show that both Polintons and Tlr elements encode two key virion proteins, the major capsid protein with the double jelly-roll fold and the minor capsid protein, known as the penton, with the single jelly-roll topology. This observation along with the previously noted conservation of the genes for viral genome packaging ATPase and adenovirus-like protease strongly suggests that Polintons and Tlr elements combine features of bona fide viruses and transposons. We propose the name ‘Polintoviruses’ to denote these putative viruses that could have played a central role in the evolution of several groups of DNA viruses of eukaryotes. PMID:24773695

  9. Conservation of major and minor jelly-roll capsid proteins in Polinton (Maverick) transposons suggests that they are bona fide viruses.

    PubMed

    Krupovic, Mart; Bamford, Dennis H; Koonin, Eugene V

    2014-04-29

    Polintons (also known as Mavericks) and Tlr elements of Tetrahymena thermophila represent two families of large DNA transposons widespread in eukaryotes. Here, we show that both Polintons and Tlr elements encode two key virion proteins, the major capsid protein with the double jelly-roll fold and the minor capsid protein, known as the penton, with the single jelly-roll topology. This observation along with the previously noted conservation of the genes for viral genome packaging ATPase and adenovirus-like protease strongly suggests that Polintons and Tlr elements combine features of bona fide viruses and transposons. We propose the name 'Polintoviruses' to denote these putative viruses that could have played a central role in the evolution of several groups of DNA viruses of eukaryotes.

  10. The role of corchorus in spreading of tomato yellow leaf curl virus on tomato in Jeddah, Saudi Arabia.

    PubMed

    Sohrab, Sayed Sartaj

    2016-03-01

    Corchorus (Corchorus capsularis L. and Corchorus olitorius L.) is one of the most important fiber crops grown in tropical and subtropical regions throughout the world. Field survey was conducted and naturally infected leaf samples were collected from corchorus and tomato plants in Jeddah, Saudi Arabia. The causal virus was transmitted by whiteflies to tomato plants and begomovirus infection was confirmed by Polymerase chain reaction. The complete viral genome and associated betasatellites were amplified, cloned and sequenced from both corchorus and tomato samples. The genetic variability and phylogenetic relationships were determined for both isolates (corchorus and tomato). The complete genome sequences showed highest (99.5 % nt) similarity with tomato yellow leaf curl virus (TYLCV) and formed closest cluster with TYLCV-Tomato reported from Jizan and Al-Qasim, Saudi Arabia and betasatellites sequences showed highest similarity (99.8 % nt) with Tomato yellow leaf curl betasatellites-Jeddah followed by Tomato yellow leaf curl Oman betasatellites and formed closed cluster with TYLCV-Tomato. On the basis of results obtained from whiteflies transmission, sequence similarity and phylogenetic relationships; it is concluded that the identified virus could be a variant of TYLCV circulating in the Kingdom. The significance of this study demonstrated that the corchorus is serving as reservoir and alternative host and playing an important role in spreading the begomovirus associated disease in the Kingdom of Saudi Arabia.

  11. Assessment of the genetic diversity of tomato yellow leaf curl virus.

    PubMed

    Wan, H J; Yuan, W; Wang, R Q; Ye, Q J; Ruan, M Y; Li, Z M; Zhou, G Z; Yao, Z P; Yang, Y J

    2015-01-26

    The objective of the present study was to analyze the genetic diversity of tomato yellow leaf curl virus (TYLCV). Representative TYLCV sequences were searched in the National Center for Biotechnology Information database. Comprehensive analysis of TYLCV was performed using bioinformatics by examining gene structure, sequence alignments, phylogeny, GC content, and homology. Forty-eight representative TYLCV sequences were selected from 48 regions in 29 countries. The results showed that all TYLCV sequences were 2752-2794 nucleotides in length, which encoded 6 open reading frames (AV1, AV2, AC1, AC2, AC3, and AC4). GC content ranged from 0.41-0.42. Sequence alignment showed a number of insertions and deletions within these TYLCV sequences. Phylogenetic tree results revealed that the sequences were divided into 10 classes; homology of the sequences ranged from 72.8 to 98.6%. All 48 sequences contained the typical structure of TYLCV, including open reading frames and intergenic regions. These results provide a theoretical basis for the identification and evolution of the virus in the future.

  12. Effects of the mutation of selected genes of cotton leaf curl Kokhran virus on infectivity, symptoms and the maintenance of cotton leaf curl Multan betasatellite.

    PubMed

    Iqbal, Zafar; Sattar, M Naeem; Kvarnheden, Anders; Mansoor, Shahid; Briddon, Rob W

    2012-10-01

    Cotton leaf curl Kokhran virus (CLCuKoV) is a cotton-infecting monopartite begomovirus (family Geminiviridae). The effects of mutation of the coat protein (CP), V2, C2 and C4 genes of CLCuKoV on infectivity and symptoms in Nicotiana benthamiana were investigated. Each mutation introduced a premature stop codon which would lead to premature termination of translation of the gene. Mutation of the CP gene abolished infectivity. However, transient expression of the CLCuKoV CP gene under the control of the Cauliflower mosaic virus 35S promoter (35S-Ko(CP)), at the point of inoculation, led to a small number of plants in which viral DNA could be detected by PCR in tissues distal to the inoculation site. Mutations of the V2, C2 and C4 genes reduced infectivity. The V2 and C2 mutants did not induce symptoms, whereas the C4 mutation was associated with attenuated symptoms. Infections of plants with the C4 mutant were associated with viral DNA levels equivalent to the wild-type virus, whereas viral DNA levels for the V2 mutant were low, detectable by Southern blot hybridisation, and for the C2 mutant were detectable only by PCR. Significantly, transient expression of the CLCuKoV C2 gene at the point of inoculation, raised virus DNA levels in tissues distal to the inoculation site such that they could be detected by Southern hybridisation, although they remained at well below the levels seen for the wild-type virus, but reduced the infectivity of the virus. These findings are consistent with earlier mutation studies of monopartite begomoviruses and our present knowledge concerning the functions of the four genes suggesting that the CP is essential for long distance spread of the virus in plants, the C4 is involved in modulating symptoms, the C2 interferes with host defence and the V2 is involved in virus movement. The results also suggest that the V2, C2 and C4 may be pathogenicity determinants. Additionally the effects of the mutations of CLCuKoV genes on infections of the

  13. A sensitive and specific hyperbranched rolling circle amplification assay and test strip for white spot syndrome virus.

    PubMed

    Zhao, Yu-Ran; Yin, Wei-Li; Yue, Zhi-Qin; Li, Ba-Fang

    2014-01-01

    White spot syndrome virus (WSSV) is a global threat to the prawn industry, and there is no simple method for field-based testing of this virus. We designed a padlock probe and primers to the capsid protein gene VP28 of WSSV, and established a hyperbranched rolling circle amplification (HRCA) assay and a corresponding strip-based test. The assay and the test strip both had similar high accuracy and specificity, and their sensitivity was about 10 copies/μL, which is 100 times higher than conventional PCR. In this study, 68 batches of prawns were tested for WSSV with the HRCA assay and test strip, and the results were compared with the PCR assay. The results indicated that both the assay and test strip had accuracy similar to each other and to the PCR results. However, the assay and strip were more sensitive and user-friendly than PCR. Establishment of this method will provide a rapid detection of WSSV and also a basis for field-based detection of animal disease.

  14. Simultaneous detection of papaya ringspot virus, papaya leaf distortion mosaic virus, and papaya mosaic virus by multiplex real-time reverse transcription PCR.

    PubMed

    Huo, P; Shen, W T; Yan, P; Tuo, D C; Li, X Y; Zhou, P

    2015-12-01

    Both the single infection of papaya ringspot virus (PRSV), papaya leaf distortion mosaic virus (PLDMV) or papaya mosaic virus (PapMV) and double infection of PRSV and PLDMV or PapMV which cause indistinguishable symptoms, threaten the papaya industry in Hainan Island, China. In this study, a multiplex real-time reverse transcription PCR (RT-PCR) was developed to detect simultaneously the three viruses based on their distinctive melting temperatures (Tms): 81.0±0.8°C for PRSV, 84.7±0.6°C for PLDMV, and 88.7±0.4°C for PapMV. The multiplex real-time RT-PCR method was specific and sensitive in detecting the three viruses, with a detection limit of 1.0×10(1), 1.0×10(2), and 1.0×10(2) copies for PRSV, PLDMV, and PapMV, respectively. Indeed, the reaction was 100 times more sensitive than the multiplex RT-PCR for PRSV, and 10 times more sensitive than multiplex RT-PCR for PLDMV. Field application of the multiplex real-time RT-PCR demonstrated that some non-symptomatic samples were positive for PLDMV by multiplex real-time RT-PCR but negative by multiplex RT-PCR, whereas some samples were positive for both PRSV and PLDMV by multiplex real-time RT-PCR assay but only positive for PLDMV by multiplex RT-PCR. Therefore, this multiplex real-time RT-PCR assay provides a more rapid, sensitive and reliable method for simultaneous detection of PRSV, PLDMV, PapMV and their mixed infections in papaya.

  15. Sweet pepper confirmed as a reservoir host for tomato yellow leaf curl virus by both agro-inoculation and whitefly-mediated inoculation.

    PubMed

    Kil, Eui-Joon; Byun, Hee-Seong; Kim, Sunhoo; Kim, Jaedeok; Park, Jungan; Cho, Seungchan; Yang, Dong-Cheol; Lee, Kyeong-Yeoll; Choi, Hong-Soo; Kim, Ji-Kwang; Lee, Sukchan

    2014-09-01

    Tomato yellow leaf curl virus (TYLCV), a member of the genus Begomovirus, has a single-stranded DNA genome. TYLCV can induce severe disease symptoms on tomato plants, but other hosts plants such as cucurbits and peppers are asymptomatic. A full-length DNA clone of a Korean TYLCV isolate was constructed by rolling-circle amplification from TYLCV-infected tomatoes in Korea. To assess relative susceptibility of sweet pepper varieties to TYLCV, 19 cultivars were inoculated with cloned TYLCV by agro-inoculation. All TYLCV-infected sweet peppers were asymptomatic, even though Southern hybridization and polymerase chain reaction analysis showed TYLCV genomic DNA accumulation in roots, stems, and newly produced shoots. Southern hybridization indicated that TYLCV replicated and moved systemically from agro-inoculated apical shoot tips to roots or newly produced shoots of sweet peppers. Whitefly-mediated inoculation experiments showed that TYLCV can be transmitted to tomatoes from TYLCV-infected sweet peppers. Taken together, these results indicate that sweet pepper can be a reservoir for TYLCV in nature.

  16. Frequent occurrence of tomato leaf curl New Delhi virus in cotton leaf curl disease affected cotton in Pakistan

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton leaf curl disease (CLCuD) in the Indian subcontinent is associated with several distinct monopartite begomoviruses and DNA satellites. However, only a single begomovirus was associated with breakdown of resistance against CLCuD in previously resistant cotton varieties. The monopartite begomov...

  17. Narrow Bottlenecks Affect Pea Seedborne Mosaic Virus Populations during Vertical Seed Transmission but not during Leaf Colonization

    PubMed Central

    Johansen, Elisabeth Ida; Simon, Vincent; Jacquemond, Mireille; Senoussi, Rachid

    2014-01-01

    The effective size of populations (Ne) determines whether selection or genetic drift is the predominant force shaping their genetic structure and evolution. Populations having high Ne adapt faster, as selection acts more intensely, than populations having low Ne, where random effects of genetic drift dominate. Estimating Ne for various steps of plant virus life cycle has been the focus of several studies in the last decade, but no estimates are available for the vertical transmission of plant viruses, although virus seed transmission is economically significant in at least 18% of plant viruses in at least one plant species. Here we study the co-dynamics of two variants of Pea seedborne mosaic virus (PSbMV) colonizing leaves of pea plants (Pisum sativum L.) during the whole flowering period, and their subsequent transmission to plant progeny through seeds. Whereas classical estimators of Ne could be used for leaf infection at the systemic level, as virus variants were equally competitive, dedicated stochastic models were needed to estimate Ne during vertical transmission. Very little genetic drift was observed during the infection of apical leaves, with Ne values ranging from 59 to 216. In contrast, a very drastic genetic drift was observed during vertical transmission, with an average number of infectious virus particles contributing to the infection of a seedling from an infected mother plant close to one. A simple model of vertical transmission, assuming a cumulative action of virus infectious particles and a virus density threshold required for vertical transmission to occur fitted the experimental data very satisfactorily. This study reveals that vertically-transmitted viruses endure bottlenecks as narrow as those imposed by horizontal transmission. These bottlenecks are likely to slow down virus adaptation and could decrease virus fitness and virulence. PMID:24415934

  18. Complete genome sequence and analysis of blackcurrant leaf chlorosis associated virus, a new member of the genus Idaeovirus.

    PubMed

    James, Delano; Phelan, James

    2017-02-11

    Blackcurrant leaf chlorosis associated virus (BCLCaV) was isolated from symptomatic blackcurrants (Ribes nigrum cv. Baldwin). The virus has a genome organization similar to that of raspberry bushy dwarf virus (RBDV), the type member of the genus Idaeovirus. The RNA-1of this virus encodes the replicase complex (ORF1, Mr 197 kDa), while RNA-2 encodes a putative movement protein (ORF2a, Mr 38.8 kDa) and the putative coat protein (ORF2b, Mr 30 kDa). A concatenated form of BCLCaV RNA-2 was detected by next-generation sequencing and confirmed by RT-PCR. BCLCaV is a new member of the genus Idaeovirus.

  19. Complete nucleotide sequences of okra isolates of Cotton leaf curl Gezira virus and their associated DNA-beta from Niger.

    PubMed

    Shih, S L; Kumar, S; Tsai, W S; Lee, L M; Green, S K

    2009-01-01

    Okra (Abelmoschus esculentus) is a major crop in Niger. In the fall of 2007, okra leaf curl disease was observed in Niger and the begomovirus and DNA-beta satellite were found associated with the disease. The complete nucleotide sequences of DNA-A (FJ469626 and FJ469627) and associated DNA-beta satellites (FJ469628 and FJ469629) were determined from two samples. This is the first report of molecular characterization of okra-infecting begomovirus and their associated DNA-beta from Niger. The begomovirus and DNA-beta have been identified as Cotton leaf curl Gezira virus and Cotton leaf curl Gezira betasatellite, respectively, which are reported to also infect okra in Egypt, Mali and Sudan.

  20. Bean leaf beetle (Coleoptera: Chrysomelidae) management for reduction of bean pod mottle virus.

    PubMed

    Krell, Rayda K; Pedigo, Larry P; Hill, John H; Rice, Marlin E

    2004-04-01

    Bean pod mottle virus (BPMV) is a management concern for soybean, Glycine max (L.), producers in the North Central states because it can cause yield loss and reduce seed quality by induction of seed coat mottling. The main vector of BPMV is the bean leaf beetle, Cerotoma trifurcata (Forster). An experiment was conducted in 2000 and 2001 at two locations in northwestern and central Iowa to test three insecticide treatments for suppression of bean leaf beetles, and subsequently, BPMV. Treatments of insecticide applications with lambda-cyhalothrin were 1) a single early-season application (23 g [AI] /ha) (2.5 oz/acre) at the VE-VC soybean developmental stage; 2) two early-season applications, the first the same as treatment 1 and a second at the same rate 9-13 d later; 3) a single early-season application the same as treatment 1, followed by a mid-season application (28 g [AI] /ha (3.2 oz/acre) at approximately R2 (flowering, near 15 July); and 4) an unsprayed control. Application of lambda-cyhalothrin after soybean emergence and again as first-generation bean leaf beetles emerged in northwestern Iowa in 2000 (treatment 3) significantly reduced beetle densities through mid-season, BPMV field incidence by 31.5%, and seed coat mottling by 31.2%, compared with the unsprayed control. Similar effects were measured at the same location when insecticide was applied twice at early season (treatment 2). Yield was 453.7 kg/ha (6.74 bu/acre) greater in treatment 2 and 525.20 kg/ha (7.80 bu/acre) greater in treatment 3 than in the unsprayed control at the northwestern site in 2000. At both locations in 2001 fewer treatment effects were observed, which was likely related to lower beetle populations in that year. Early-season insecticide sprays targeted at overwintered beetles on VC-VE reduced the initial population of vector insects and may have contributed to a lower first-generation population because of reduced overwintered beetle oviposition. In 1 year at one location there

  1. Monitoring the dynamics of emergence of a non-canonical recombinant of Tomato yellow leaf curl virus and displacement of its parental viruses in tomato.

    PubMed

    Belabess, Z; Dallot, S; El-Montaser, S; Granier, M; Majde, M; Tahiri, A; Blenzar, A; Urbino, C; Peterschmitt, M

    2015-12-01

    Recombinant viruses are increasingly being reported but the dynamics of their emergence is rarely documented. A new recombinant Tomato yellow leaf curl virus (TYLCV-IS76) was detected for the first time in 2010 in Southern Morocco (Souss). An original diagnostic tool was needed to fit its unusual recombination profile. Although IS76 was detected following the appearance of Tylc symptoms on tolerant tomato plants, symptoms could not be associated to IS76 or to a synergy with criniviruses. According to infection profiles of Tylc-associated viruses determined on 879 plant samples collected between 1998 and 2014 and a Bayesian inference applied to genomic sequences of representatives of TYLCV, IS76 emerged in Southern Morocco at the end of the 1990s, replaced the parental viruses between 2004 and 2012 in Souss and is spreading towards the North of Morocco. The emergence of IS76 coincides with the increasing use of tolerant cultivars in the 2000s.

  2. Tomato chlorotic leaf distortion virus, a new bipartite begomovirus infecting Solanum lycopersicum and Capsicum chinense in Venezuela.

    PubMed

    Zambrano, Karla; Geraud-Pouey, Francis; Chirinos, Doris; Romay, Gustavo; Marys, Edgloris

    2011-12-01

    Virus isolate T217L was obtained from a diseased tomato (Solanum lycopersicum) plant showing leaf deformation and chlorotic mottle symptoms near Maracaibo in the state of Zulia, Venezuela. Full-length DNA-A and DNA-B molecules of T217L were cloned and sequenced. The genome organization of T217L was identical to the bipartite genomes of other begomoviruses described from the Americas. Characteristic disease symptoms were reproduced in S. lycopersicum and Capsicum annum plants inoculated using the cloned viral DNA-A and DNA-B components, confirming disease aetiology. A sequence analysis of DNA-A showed that the T217L isolate has the highest sequence identity (84%) with sida yellow mosaic Yucatan virus (SiYMYuV), sida golden mosaic Honduras virus (SiGMHV) and bean dwarf mosaic virus (BDMV) isolates. This is less than the 89% identity in the DNA-A component that has been defined as the threshold value for the demarcation of species in the genus Begomovirus. The molecular data show that isolate T217L belongs to a novel tentative begomovirus species, for which the name tomato chlorotic leaf distortion virus is proposed. TCLDV was also detected in symptomatic C. chinense plants growing near the T217L-infected plant.

  3. In Vitro Inhibition of Cytopathic Effect of Influenza Virus and Human Immunodeficiency Virus by Bamboo Leaf Extract Solution and Sodium Copper Chlorophyllin

    PubMed Central

    Ito, Akiko; Tsuneki, Akeno; Yoshida, Yu; Ryoke, Kazuo; Kaidoh, Toshiyuki; Kageyama, Seiji

    2016-01-01

    Background Although the link between oral and oropharyngeal health status and susceptibility to infection has long been recognized, there is a limit to the selection of antiseptics for oral care. Methods Madin-Darby canine kidney (MDCK) cells were exposed to influenza virus and cultured in the presence or absence of test reagents: bamboo leaf extract solution and sodium copper chrolophyllin. MDCK cells were pre-incubated with the reagents to assess the inhibitory activity at adsorption (viral attachment). Similarly, anti-HIV activity and the inhibitory mechanism at adsorption were assessed by MT-2 cell culture system. Mixture of HIV and bamboo leaf extract solution was fixed and examined by transmission electron microscopy. Results The 50% inhibitory concentration (IC50) of bamboo leaf extract solution against influenza virus and the 50% cytotoxic concentration (CC50) in MDCK cells of the solution lay between 0.0313–0.0625% and 0.5–1.0%. The solution inhibited the influenza virus adsorption at the concentration of 0.5% (P < 0.05). The values of IC50 and CC50 of sodium copper chlorophyllin lay between 50–100 µM and 200–400 µM, respectively. This inhibited the virus adsorption at 200 µM (P < 0.05). The bamboo leaf extract solution showed values of IC50 against HIV and CC50 in MT-2 cells at around 0.0313% and between 0.25–0.5%, respectively. This solution inhibited HIV adsorption at 1.25% (P < 0.05). The IC50 and CC50 of sodium copper chlorophyllin lay between 50–100 µM and 200–400 µM, respectively. Sodium copper chlorophyllin inhibited HIV adsorption at 2.5 mM (P < 0.05). HIV particles survived after the exposure to 0.5% bamboo leaf extract solution. Conclusion Sodium copper chlorophyllin exerted antiviral activities against influenza virus and HIV as the major ingredient of bamboo leaf extract solution by blocking adsorption. This mechanism of action is different completely from the one of povidone-iodine. PMID:27046952

  4. The spread of tomato yellow leaf curl virus from the Middle East to the world.

    PubMed

    Lefeuvre, Pierre; Martin, Darren P; Harkins, Gordon; Lemey, Philippe; Gray, Alistair J A; Meredith, Sandra; Lakay, Francisco; Monjane, Adérito; Lett, Jean-Michel; Varsani, Arvind; Heydarnejad, Jahangir

    2010-10-28

    The ongoing global spread of Tomato yellow leaf curl virus (TYLCV; Genus Begomovirus, Family Geminiviridae) represents a serious looming threat to tomato production in all temperate parts of the world. Whereas determining where and when TYLCV movements have occurred could help curtail its spread and prevent future movements of related viruses, determining the consequences of past TYLCV movements could reveal the ecological and economic risks associated with similar viral invasions. Towards this end we applied Bayesian phylogeographic inference and recombination analyses to available TYLCV sequences (including those of 15 new Iranian full TYLCV genomes) and reconstructed a plausible history of TYLCV's diversification and movements throughout the world. In agreement with historical accounts, our results suggest that the first TYLCVs most probably arose somewhere in the Middle East between the 1930s and 1950s (with 95% highest probability density intervals 1905-1972) and that the global spread of TYLCV only began in the 1980s after the evolution of the TYLCV-Mld and -IL strains. Despite the global distribution of TYLCV we found no convincing evidence anywhere other than the Middle East and the Western Mediterranean of epidemiologically relevant TYLCV variants arising through recombination. Although the region around Iran is both the center of present day TYLCV diversity and the site of the most intensive ongoing TYLCV evolution, the evidence indicates that the region is epidemiologically isolated, which suggests that novel TYLCV variants found there are probably not direct global threats. We instead identify the Mediterranean basin as the main launch-pad of global TYLCV movements.

  5. In vitro rearing of Perkinsiella saccharicida and the use of leaf segments to assay Fiji disease virus transmission.

    PubMed

    Hughes, G L; Allsopp, P G; Brumbley, S M; Johnson, K N; O'Neill, S L

    2008-07-01

    Fiji leaf gall (FLG) is caused by the Reovirus, Fiji disease virus (FDV), which is transmitted to sugarcane by planthoppers of the genus Perkinsiella. Low vector transmission rates and slow disease symptom development make experimentation within the FDV-Perkinsiella-sugarcane system inherently difficult. A laboratory-based technique was devised to rear the vector using sugarcane leaves as a food source. Planthoppers were reared on sugarcane leaf segments embedded in agarose enclosed within plastic containers. To provide a nondestructive assay for determination of the inoculation potential of planthoppers, FDV was detected by reverse transcription-polymerase chain reaction (RT-PCR) in newly infected sugarcane leaf segments following exposure to viruliferous planthoppers. Leaf segment inoculation correlated with development of FLG symptoms in whole plants that were fed on by the same planthoppers. Analysis of FDV RNAs within the planthopper, measured by quantitative RT-PCR (qRT-PCR), indicated that FDV RNA concentration was associated with successful inoculation of the leaf segment, transmission of FDV to sugarcane and subsequent development of FLG in plants. Quantification of FDV RNA within planthoppers provided an additional measure to assess vector competence in individuals.

  6. Introgression of cotton leaf curl virus-resistant genes from Asiatic cotton (Gossypium arboreum) into upland cotton (G. hirsutum).

    PubMed

    Ahmad, S; Mahmood, K; Hanif, M; Nazeer, W; Malik, W; Qayyum, A; Hanif, K; Mahmood, A; Islam, N

    2011-10-07

    Cotton is under the constant threat of leaf curl virus, which is a major constraint for successful production of cotton in the Pakistan. A total of 3338 cotton genotypes belonging to different research stations were screened, but none were found to be resistant against the Burewala strain of cotton leaf curl virus (CLCuV). We explored the possibility of transferring virus-resistant genes from Gossypium arboreum (2n = 26) into G. hirsutum (2n = 52) through conventional breeding techniques. Hybridization was done manually between an artificial autotetraploid of G. arboreum and an allotetraploid G. hirsutum, under field conditions. Boll shedding was controlled by application of exogenous hormones, 50 mg/L gibberellic acid and 100 mg/L naphthalene acetic acid. Percentage pollen viability in F(1) hybrids was 1.90% in 2(G. arboreum) x G. hirsutum and 2.38% in G. hirsutum x G. arboreum. Cytological studies of young buds taken from the F(1) hybrids confirmed that they all were sterile. Resistance against CLCuV in the F(1) hybrids was assessed through grafting, using the hybrid plant as the scion; the stock was a virus susceptible cotton plant, tested under field and greenhouse conditions. All F(1) cotton hybrids showed resistance against CLCuV, indicating that it is possible to transfer resistant genes from the autotetraploid of the diploid donor specie G. arboreum into allotetraploid G. hirsutum through conventional breeding, and durable resistance against CLCuV can then be deployed in the field.

  7. Amplicon based RNA interference targeting V2 gene of cotton leaf curl Kokhran virus-Burewala strain can provide resistance in transgenic cotton plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An RNAi based gene construct designated “C2” was used to target the V2 region of the cotton leaf curl virus (CLCuV) genome which is responsible for virus movement. The construct was transformed into two elite cotton varieties MNH-786 and VH-289. A shoot apex method of plant transformation using Agr...

  8. Aphid transmission of Lettuce necrotic leaf curl virus, a member of a tentative new subgroup within the genus Torradovirus.

    PubMed

    Verbeek, Martin; Dullemans, Annette M; van der Vlugt, René A A

    2017-02-20

    Lettuce necrotic leaf curl virus (LNLCV) was described as the first non-tomato-infecting member of the genus Torradovirus. Until today, the virus was found only in The Netherlands in two different areas in open field crops of lettuce. In 2015, LNLCV was accepted by the ICTV as a new member of the genus Torradovirus. The tomato-infecting (TI) torradoviruses Tomato torrado virus (ToTV), Tomato marchitez virus (ToMarV) and Tomato chocolàte virus (ToChV) are transmitted by at least three whitefly species in a semi-persistent and stylet-borne manner. As LNLCV was transmitted in open fields in The Netherlands, where whiteflies are present only in low incidence, transmission studies were set up to identify the natural vector of LNLCV. Whitefly species which survive Dutch open field conditions during summer, as well as lettuce colonizing aphid species, were tested for their ability to transmit LNLCV. Lengths of acquisition and inoculation periods were chosen in accordance with the conditions for TI torradoviruses. Transmission experiments involving whiteflies were never successful. Transmission with aphids was only successful in case of the lettuce-currant aphid, Nasonovia ribisnigri. Localization of LNLCV virions in N. ribisnigri with a nested RT-PCR indicated the stylets as possible retention sites. The willow-carrot aphid Cavariella aegopodii did not transmit LNLCV in our transmission experiment but the virus could be detected in the stylets of this aphid, leaving C. aegopodii as a possible vector for LNLCV.

  9. The hypersensitive response to tomato leaf curl New Delhi virus nuclear shuttle protein is inhibited by transcriptional activator protein.

    PubMed

    Hussain, Mazhar; Mansoor, Shahid; Iram, Shazia; Zafar, Yusuf; Briddon, Rob W

    2007-12-01

    The hypersensitive response (HR) is a common feature of plant disease resistance reactions and a type of programmed cell death (PCD). Many pathogens are able to modulate pathways involved in cell death. In contrast to animal viruses, inhibitors of PCD activity have not been identified for plant-infecting viruses. Previously, we have reported that the nuclear shuttle protein (NSP) of Tomato leaf curl New Delhi virus (ToLCNDV) induces an HR in Nicotiana tabacum and Lycopersicon esculentum plants when expressed under the control of the Cauliflower mosaic virus 35S promoter. However, HR is not evident in plants infected with ToLCNDV, suggesting that the virus encodes a factor (or factors) that counters this response. Analysis of all ToLCNDV-encoded genes pinpointed the transcriptional activator protein (TrAP) as the factor mediating the anti-HR effect. Deletion mutagenesis showed the central region of TrAP, containing a zinc finger domain and nuclear localization signal, to be important in inhibiting the HR. These results demonstrate that TrAP counters HR-induced cell death, the first such activity identified for a plant-infecting virus.

  10. Detection and characterization of a new betasatellite: variation in disease symptoms of tomato leaf curl Pakistan virus-India due to associated betasatellite.

    PubMed

    Kumar, Jitendra; Singh, Sudhir P; Kumar, Abhinav; Khan, Jawaid A; Tuli, Rakesh

    2013-01-01

    A begomovirus and its associated betasatellites were amplified and sequenced from tobacco plants affected with leaf curl disease. The begomovirus was identified as a new strain of tomato leaf curl Pakistan virus (ToLCPKV), which is referred to here as ToLCPKV-India. A previously known betasatellite [tomato leaf curl Patna betasatellite (ToLCPaB)] and a new betasatellite were also found in leaf-curl-affected samples. The use of infectious clones of ToLCPKV-IN plus ToLCPaB for agroinoculation led to typical leaf curl, while ToLCPKV-IN together with the new betasatellite resulted in curling and chlorosis of leaves. Based on these disease symptoms, we propose to name the new betasatellite tobacco leaf chlorosis betasatellite (TbLChB).

  11. Genetic diversity of tomato-infecting Tomato yellow leaf curl virus (TYLCV) isolates in Korea.

    PubMed

    Kim, Sue Hoon; Oh, Sung; Oh, Tae-Kyun; Park, Jae Sung; Kim, Sei Chang; Kim, Seong Hwan; Kim, Young Shik; Hong, Jeum Kyu; Sim, Sang-Yun; Park, Kwon Seo; Lee, Hwan Gu; Kim, Kyung Jae; Choi, Chang Won

    2011-02-01

    Epidemic outbreaks of Tomato yellow leaf curl virus (TYLCV) diseases occurred in greenhouse grown tomato (Solanum lycopersicum) plants of Busan (TYLCV-Bus), Boseong (TYLCV-Bos), Hwaseong (TYLCV-Hwas), Jeju Island (TYLCV-Jeju), and Nonsan (TYLCV-Nons) in Korea during 2008-2009. Tomato disease by TYLCV has never occurred in Korea before. We synthesized the full-length genomes of each TYLCV isolate from the tomato plants collected at each area and determined their nucleotides (nt) sequences and deduced the amino acids of six open reading frames in the genomes. TYLCV-Bus and -Bos genomes shared higher nt identities with four Japanese isolates -Ng, -Omu, -Mis, and -Miy. On the other hand, TYLCV-Hwas, -Jeju, and -Nons genomes shared higher nt identities with five Chinese isolates TYLCV-AH1, -ZJ3, -ZJHZ12, -SH2, -Sh10, and two Japanese isolates -Han and -Tosa. On the basis of a neighbor-joining tree, five Korean TYLCV isolates were separated into three clades. TYLCV-Bus and -Bos formed the first clade, clustering with four Japanese isolates TYLCV-Mis, -Omu, -Ng, and -Miy. TYLCV-Jeju and -Nons formed the second clade, clustering with two Chinese isolates -ZJHZ212 and -Sh10. TYLCV-Hwas was clustered with two Japanese isolates -Han and -Tosa and three Chinese isolates -AH1, -ZJ3, and -SH2. Two fragments that had a potentially recombinant origin were identified using the RDP, GENECONV, BootScan, MaxChi, Chimaera, SiScan, and 3Seq methods implemented in RDP3.41. On the basis of RDP analysis, all TYLCV isolates could originated from the interspecies recombination between TYLCV-Mld[PT] isolated from Portugal as a major parent and TYLCTHV-MM isolated from Myanmar as a minor parent.

  12. Highly sensitive serological methods for detecting tomato yellow leaf curl virus in tomato plants and whiteflies

    PubMed Central

    2013-01-01

    Background Tomato yellow leaf curl virus (TYLCV) is a member of the genus Begomovirus in the family Geminiviridae, which causes severe losses in tomato production in tropic and subtropic regions. Methods The purified TYLCV virions were used as the immunogen to produce monoclonal antibodies (MAbs) using the hybridoma technology. MAb-based dot enzyme-linked immunosorbent assay (dot-ELISA) and direct tissue blot immunoassay (DTBIA) were developed for sensitive, simple, and rapid detection of TYLCV in field tomato and whitefly (Bemisia tabaci) samples collected from TYLCV prevalent provinces in China. Results Using the hybridoma technology, six murine MAbs (1C4, 8D10, 6E3, 2F2, 3F4 and 4G3) against TYLCV were prepared. Using the MAb 1C4, dot-ELISA and DTBIA were then established for detecting TYLCV in field tomato and whitefly samples collected from TYLCV prevalent provinces in China. The dot-ELISA could detect TYLCV in infected tissue crude extract diluted at 1:5,120 (w/v, g mL-1), and in viruliferous whitefly homogenate diluted at 1:128 (individual whitefly/μL), respectively. Field tomato samples (n=487) and whitefly samples (n=110) from TYLCV prevalent districts in China were screened for the presence of TYLCV using the two developed methods, and the results were further confirmed by PCR and nucleotide sequencing. The survey revealed that TYLCV is widespread on tomato plants in Zhejiang, Shandong and Henan provinces in China. Conclusions The developed dot-ELISA is very suitable for the routine detection of TYLCV in field tomato and whitefly samples, and the DTBIA is more suitable for the routine detection of TYLCV in large-scale tomato plant samples collected from TYLCV prevalent areas. PMID:23647724

  13. Difference of physiological characters in dark green islands and yellow leaf tissue of Cucumber mosaic virus (CMV)-infected Nicotiana tabacum leaves.

    PubMed

    Shang, Jing; Xi, De-Hui; Yuan, Shu; Xu, Fei; Xu, Mo-Yun; Qi, Hai-Long; Wang, Shao-Dong; Huang, Qing-Rong; Wen, Lin; Lin, Hong-Hui

    2010-01-01

    Dark green islands (DGIs) are a common symptom of plants systemically infected with the mosaic virus. DGIs are clusters of green leaf cells that are free of virus but surrounded by yellow leaf tissue that is full of virus particles. In Cucumber mosaic virus (CMV)-infected Nicotiana tabacum leaves, the respiration and photosynthesis capabilities of DGIs and yellow leaf tissues were measured. The results showed that the cyanide-resistant respiration was enhanced in yellow leaf tissue and the photosynthesis was declined, while in DGIs they were less affected. The activities of the oxygen-scavenging enzymes catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) in infected leaves were significantly higher than those in the healthy leaves, and the enzyme activities in DGIs were always lower than in the yellow leaf tissues. Reactive oxygen species (ROS) staining showed that the hydrogen peroxide content in yellow leaf tissues was apparently higher than that in DGIs, while the superoxide content was on the contrary. Formation of DGIs may be a strategy of the host plants resistance to the CMV infection.

  14. New insecticides for management of tomato yellow leaf curl, a virus vectored by the silverleaf whitefly, Bemisia tabaci.

    PubMed

    Smith, H A; Giurcanu, M C

    2014-01-01

    Greenhouse studies using a randomized complete block design were carried out to evaluate the effect of six insecticides on transmission of Tomato yellow leaf curl virus (TYLCV) by the silverleaf whitefly, Bemisia tabaci biotype B Gennadius (Hemiptera: Aleyrodidae) to tomato, Lycopersicon esculentum (Miller) (Solanales: Solanaceae), seedlings that were inoculated with whiteflies from a TYLCV colony in cages 3, 7, or 14 d after treatment with insecticide. The purpose was to reveal differences in residual efficacy of four materials that are nearing registration for use on tomato-cyazypyr, flupyradifurone, pyrafluquinazon, and sulfoxaflor-and to compare them with two established insecticides, pymetrozine and a zeta-cypermethrin/bifenthrin combination. Differences in efficacy were expected because these six materials represent five distinct modes of action and both contact and systemic materials. Percentage of tomato seedlings expressing virus symptoms tended to be lowest in seedlings treated with flupyradifurone. The zeta-cypermethrin/bifenthrin insecticide demonstrated comparable efficacy to flupyradifurone in some trials at 3 and 7 d after treatment inoculations, but not the 14 d after treatment inoculation. Pyrafluquinazon was not statistically different from cyazypyr or sulfoxaflor in percentage of plants with virus symptoms in any trial. Percentage virus in the cyazypyr and sulfoxaflor treatments was not statistically different in the 3 and 7 d after treatment inoculations. Among seedlings treated with insecticide, percentage with virus symptoms tended to be highest in the seedlings treated with pymetrozine.

  15. Development of a full-genome cDNA clone of Citrus leaf blotch virus and infection of citrus plants.

    PubMed

    Vives, María Carmen; Martín, Susana; Ambrós, Silvia; Renovell, Agueda; Navarro, Luis; Pina, Jose Antonio; Moreno, Pedro; Guerri, José

    2008-11-01

    Citrus leaf blotch virus (CLBV), a member of the family Flexiviridae, has a ~9-kb single-stranded, positive-sense genomic RNA encapsidated by a 41-kDa coat protein. CLBV isolates are associated with symptom production in citrus including leaf blotching of Dweet tangor and stem pitting in Etrog citron (Dweet mottle disease), and some isolates are associated with bud union crease on trifoliate rootstocks, but Koch's postulates for this virus were not fulfilled. A full-genome cDNA of CLBV isolate SRA-153, which induces bud union crease, was placed under the T7 promoter (clone T7-CLBV), or between the 35S promoter and the Nos-t terminator, with or without a ribozyme sequence downstream of the CLBV sequence (clones 35SRbz-CLBV and 35S-CLBV). RNA transcripts from T7-CLBV failed to infect Etrog citron and Nicotiana occidentalis and N. benthamiana plants, whereas agro-inoculation with binary vectors carrying 35SRbz-CLBV or 35S-CLBV, and the p19 silencing suppressor, caused systemic infection and production of normal CLBV virions. Virus accumulation was similar in citron plants directly agro-infiltrated, or mechanically inoculated with wild-type or 35SRbz-CLBV-derived virions from Nicotiana, and the three sources incited the symptoms characteristic of Dweet mottle disease, but not bud union crease. Our results show that (1) virions derived from an infectious clone show the same replication, movement and pathogenicity characteristics as the wild-type CLBV; (2) CLBV is the causal agent of Dweet mottle disease but not of the bud union crease syndrome; and (3) for the first time an RNA virus could be successfully agro-inoculated on citrus plants. This infectious clone may become a useful viral vector for citrus genomic studies.

  16. Comparison of transmission of Papaya leaf curl China virus among four cryptic species of the whitefly Bemisia tabaci complex.

    PubMed

    Guo, Tao; Guo, Qi; Cui, Xi-Yun; Liu, Yin-Quan; Hu, Jian; Liu, Shu-Sheng

    2015-10-21

    Begomoviruses are transmitted by cryptic species of the whitefly Bemisia tabaci complex, often in a species-specific manner. Papaya leaf curl China virus (PaLCuCNV) has been recorded to infect several crops including papaya, tomato and tobacco in China. To help assess the risks of spread of this virus, we compared the acquisition, retention and transmission of PaLCuCNV among four species of whiteflies, Middle East-Asia Minor 1 (MEAM1), Mediterranean (MED), Asia 1 and Asia II 7. All four species of whiteflies are able to acquire, retain and transmit the virus, but with different levels of efficiency. Transmission tests using tomato as the host plant showed that MEAM1 transmitted PaLCuCNV with substantially higher efficiency than did MED, Asia 1 and Asia II 7. Furthermore, accumulation of PaLCuCNV in the whiteflies was positively associated with its efficiency of transmitting the virus. Altogether, these findings indicate that MEAM1 is the most efficient vector for PaLCuCNV in the four species of whiteflies, and suggest that risks of PaLCuCNV pandemics are high in regions where MEAM1 occurs.

  17. Identification of a Severe Acute Respiratory Syndrome Coronavirus-Like Virus in a Leaf-Nosed Bat in Nigeria

    PubMed Central

    Quan, Phenix-Lan; Firth, Cadhla; Street, Craig; Henriquez, Jose A.; Petrosov, Alexandra; Tashmukhamedova, Alla; Hutchison, Stephen K.; Egholm, Michael; Osinubi, Modupe O. V.; Niezgoda, Michael; Ogunkoya, Albert B.; Briese, Thomas; Rupprecht, Charles E.; Lipkin, W. Ian

    2010-01-01

    Bats are reservoirs for emerging zoonotic viruses that can have a profound impact on human and animal health, including lyssaviruses, filoviruses, paramyxoviruses, and severe acute respiratory syndrome coronaviruses (SARS-CoVs). In the course of a project focused on pathogen discovery in contexts where human-bat contact might facilitate more efficient interspecies transmission of viruses, we surveyed gastrointestinal tissue obtained from bats collected in caves in Nigeria that are frequented by humans. Coronavirus consensus PCR and unbiased high-throughput pyrosequencing revealed the presence of coronavirus sequences related to those of SARS-CoV in a Commerson’s leaf-nosed bat (Hipposideros commersoni). Additional genomic sequencing indicated that this virus, unlike subgroup 2b CoVs, which includes SARS-CoV, is unique, comprising three overlapping open reading frames between the M and N genes and two conserved stem-loop II motifs. Phylogenetic analyses in conjunction with these features suggest that this virus represents a new subgroup within group 2 CoVs. PMID:21063474

  18. Comparison of transmission of Papaya leaf curl China virus among four cryptic species of the whitefly Bemisia tabaci complex

    PubMed Central

    Guo, Tao; Guo, Qi; Cui, Xi-Yun; Liu, Yin-Quan; Hu, Jian; Liu, Shu-Sheng

    2015-01-01

    Begomoviruses are transmitted by cryptic species of the whitefly Bemisia tabaci complex, often in a species-specific manner. Papaya leaf curl China virus (PaLCuCNV) has been recorded to infect several crops including papaya, tomato and tobacco in China. To help assess the risks of spread of this virus, we compared the acquisition, retention and transmission of PaLCuCNV among four species of whiteflies, Middle East-Asia Minor 1 (MEAM1), Mediterranean (MED), Asia 1 and Asia II 7. All four species of whiteflies are able to acquire, retain and transmit the virus, but with different levels of efficiency. Transmission tests using tomato as the host plant showed that MEAM1 transmitted PaLCuCNV with substantially higher efficiency than did MED, Asia 1 and Asia II 7. Furthermore, accumulation of PaLCuCNV in the whiteflies was positively associated with its efficiency of transmitting the virus. Altogether, these findings indicate that MEAM1 is the most efficient vector for PaLCuCNV in the four species of whiteflies, and suggest that risks of PaLCuCNV pandemics are high in regions where MEAM1 occurs. PMID:26486606

  19. Genome organization of Tobacco leaf curl Zimbabwe virus, a new, distinct monopartite begomovirus associated with subgenomic defective DNA molecules.

    PubMed

    Paximadis, M; Rey, M E

    2001-12-01

    The complete DNA A of the begomovirus Tobacco leaf curl Zimbabwe virus (TbLCZWV) was sequenced: it comprises 2767 nucleotides with six major open reading frames encoding proteins with molecular masses greater than 9 kDa. Full-length TbLCZWV DNA A tandem dimers, cloned in binary vectors (pBin19 and pBI121) and transformed into Agrobacterium tumefaciens, were systemically infectious upon agroinoculation of tobacco and tomato. Efforts to identify a DNA B component were unsuccessful. These findings suggest that TbLCZWV is a new member of the monopartite group of begomoviruses. Phylogenetic analysis identified TbLCZWV as a distinct begomovirus with its closest relative being Chayote mosaic virus. Abutting primer PCR amplified ca. 1300 bp molecules, and cloning and sequencing of two of these molecules revealed them to be subgenomic defective DNA molecules originating from TbLCZWV DNA A. Variable symptom severity associated with tobacco leaf curl disease and TbLCZWV is discussed.

  20. Use of Posttranscription Gene Silencing in Squash to Induce Resistance against the Egyptian Isolate of the Squash Leaf Curl Virus

    PubMed Central

    Taha, Omnia; Farouk, Inas; Abdallah, Abdelhadi

    2016-01-01

    Squash leaf curl virus (SqLCV) is a bipartite begomovirus affecting squash plants. It is transmitted by whitefly Bemisia tabaci biotype B causing severe leaf curling, vein banding, and molting ending by stunting. In this study full-length genomic clone of SqLCV Egyptian isolated and posttranscriptional gene silencing (PTGS) has been induced to develop virus resistance. The Noubaria SqLCV has more than 95% homology with Jordon, Israel, Lebanon, Palestine, and Cairo isolates. Two genes fragment from SqLCV introduced in sense and antisense orientations using pFGC5049 vector to be expressed as hairpin RNA. The first fragment was 348 bp from replication associated protein gene (Rep). The second fragment was 879 bp representing the full sequence of the movement protein gene (BC1). Using real-time PCR, a silencing record of 97% has been recorded to Rep/TrAP construct; as a result it has prevented the appearance of viral symptoms in most tested plants up to two months after infection, while construct containing the BC1 gene scored a reduction in the accumulation of viral genome expression as appearing in real-time PCR results 4.6-fold giving a silencing of 79%, which had a positive effect on symptoms development in most tested plants. PMID:27034922

  1. Insecticidal Effects on the Spatial Progression of Tomato Yellow Leaf Curl Virus and Movement of Its Whitefly Vector in Tomato.

    PubMed

    Dempsey, M; Riley, D G; Srinivasan, R

    2017-03-08

    Commercial management of whitefly-transmitted Tomato yellow leaf curl virus (TYLCV) typically relies on insecticide control of whitefly vectors as a first line of defense. We quantified this effect in crop tunnel studies, with validation in a tomato field setting. Tomato yellow leaf curl virus-infected and Bemisia tabaci (Gennadius)-infested source plants were planted at the beginning of tunneled rows to serve as inoculum source, so that movement of whiteflies and TYLCV symptoms could be tracked down the length of the tunnel over time. Tunnel study results showed that proximity to the source plant was a more important factor than insecticide treatments. Insecticide-treated tomato transplants did tend to suppress whitefly incidence and slowed TYLCV movement in comparison with the untreated check; however, tomato plants planted closer to the source plant had higher incidence of whiteflies and TYLCV infection, regardless of treatment. In a large tomato plot study with a controlled inoculum source, insecticide treatments significantly reduced the spread of TYLCV. When uninhibited by insecticide treatment, 80% of the TYLCV spread was restricted to <15 m from the source plant (<11 m in the validation study), with insecticide treatment generally reducing the distance and magnitude of this spread.

  2. Molecular Characterization of Tomato Leaf Curl China Virus, Infecting Tomato Plants in China, and Functional Analyses of Its Associated Betasatellite▿†

    PubMed Central

    Yang, Xiuling; Guo, Wei; Ma, Xinying; An, Qianli; Zhou, Xueping

    2011-01-01

    A novel tomato-infecting begomovirus from Guangxi province, China, was identified and characterized, for which the name Tomato leaf curl China virus (ToLCCNV) was proposed. Phylogenetic and recombination analyses of the virus genomic sequences suggested that ToLCCNV may have arisen by recombination among Tomato leaf curl Vietnam virus (ToLCVV), Tomato leaf curl Gujarat virus (ToLCGV), and an unknown virus. A betasatellite molecule was found to be associated with ToLCCNV (ToLCCNB), and its complete nucleotide sequences were determined. Infectious clones of ToLCCNV and ToLCCNB were constructed and then used for agro-inoculation of plants; ToLCCNV alone infected Nicotiana benthamiana, Nicotiana glutinosa, Petunia hybrida, and Solanum lycopersicum plants, but no symptoms were induced. ToLCCNB was required for induction of leaf curl disease in these hosts. The βC1 protein of ToLCCNB was identified as a suppressor of RNA silencing and accumulated primarily in the nucleus. Deletion mutagenesis of βC1 showed that the central part of βC1 (amino acids 44 to 74) was responsible for both the suppressor activity and nuclear localization. PMID:21378048

  3. Cotton Leaf Curl Multan Virus-Derived Viral Small RNAs Can Target Cotton Genes to Promote Viral Infection

    PubMed Central

    Wang, Jinyan; Tang, Yafei; Yang, Yuwen; Ma, Na; Ling, Xitie; Kan, Jialiang; He, Zifu; Zhang, Baolong

    2016-01-01

    RNA silencing is a conserved mechanism in plants that targets viruses. Viral small RNAs (vsiRNAs) can be generated from viral double-stranded RNA replicative intermediates within the infected host, or from host RNA-dependent RNA polymerases activity on viral templates. The abundance and profile of vsiRNAs in viral infections have been reported previously. However, the involvement of vsiRNAs during infection of the Geminiviridae family member cotton leaf curl virus (CLCuD), which causes significant economic losses in cotton growing regions, remains largely uncharacterized. Cotton leaf curl Multan virus (CLCuMuV) associated with a betasatellite called Cotton leaf curl Multan betasatellite (CLCuMuB) is a major constraint to cotton production in South Asia and is now established in Southern China. In this study, we obtained the profiles of vsiRNAs from CLCuMV and CLCuMB in infected upland cotton (Gossypium hirsutum) plants by deep sequencing. Our data showed that vsiRNA that were derived almost equally from sense and antisense CLCuD DNA strands accumulated preferentially as 21- and 22-nucleotide (nt) small RNA population and had a cytosine bias at the 5′-terminus. Polarity distribution revealed that vsiRNAs were almost continuously present along the CLCuD genome and hotspots of sense and antisense strands were mainly distributed in the Rep proteins region of CLCuMuV and in the C1 protein of CLCuMuB. In addition, hundreds of host transcripts targeted by vsiRNAs were predicted, many of which encode transcription factors associated with biotic and abiotic stresses. Quantitative real-time polymerase chain reaction analysis of selected potential vsiRNA targets showed that some targets were significantly down-regulated in CLCuD-infected cotton plants. We also verified the potential function of vsiRNA targets that may be involved in CLCuD infection by virus-induced gene silencing (VIGS) and 5′-rapid amplification of cDNA end (5′-RACE). Here, we provide the first report

  4. Genetic Dissection of Novel QTLs for Resistance to Leaf Spots and Tomato Spotted Wilt Virus in Peanut (Arachis hypogaea L.)

    PubMed Central

    Pandey, Manish K.; Wang, Hui; Khera, Pawan; Vishwakarma, Manish K.; Kale, Sandip M.; Culbreath, Albert K.; Holbrook, C. Corley; Wang, Xingjun; Varshney, Rajeev K.; Guo, Baozhu

    2017-01-01

    Peanut is an important crop, economically and nutritiously, but high production cost is a serious challenge to peanut farmers as exemplified by chemical spray to control foliar diseases such as leaf spots and thrips, the vectors of tomato spotted wilt virus (TSWV). The objective of this research was to map the quantitative trait loci (QTLs) for resistance to leaf spots and TSWV in one recombinant inbred line (RIL) mapping population of “Tifrunner × GT-C20” for identification of linked markers for marker-assisted breeding. Here, we report the improved genetic linkage map with 418 marker loci with a marker density of 5.3 cM/loci and QTLs associated with multi-year (2010–2013) field phenotypes of foliar disease traits, including early leaf spot (ELS), late leaf spot (LLS), and TSWV. A total of 42 QTLs were identified with phenotypic variation explained (PVE) from 6.36 to 15.6%. There were nine QTLs for resistance to ELS, 22 QTLs for LLS, and 11 QTLs for TSWV, including six, five, and one major QTLs with PVE higher than 10% for resistance to each disease, respectively. Of the total 42 QTLs, 34 were mapped on the A sub-genome and eight mapped on the B sub-genome suggesting that the A sub-genome harbors more resistance genes than the B sub-genome. This genetic linkage map was also compared with two diploid peanut physical maps, and the overall co-linearity was 48.4% with an average co-linearity of 51.7% for the A sub-genome and 46.4% for the B sub-genome. The identified QTLs associated markers and potential candidate genes will be studied further for possible application in molecular breeding in peanut genetic improvement for disease resistance. PMID:28197153

  5. A severe symptom phenotype in tomato in Mali is caused by a reassortant between a novel recombinant begomovirus (Tomato yellow leaf curl Mali virus) and a betasatellite.

    PubMed

    Chen, Li-Fang; Rojas, Maria; Kon, Tatsuya; Gamby, Kadiatou; Xoconostle-Cazares, Beatriz; Gilbertson, Robert L

    2009-05-01

    Tomato production in West Africa has been severely affected by begomovirus diseases, including yellow leaf curl and a severe symptom phenotype, characterized by extremely stunted and distorted growth and small deformed leaves. Here, a novel recombinant begomovirus from Mali, Tomato yellow leaf curl Mali virus (TYLCMLV), is described that, alone, causes tomato yellow leaf curl disease or, in combination with a betasatellite, causes the severe symptom phenotype. TYLCMLV is an Old World monopartite begomovirus with a hybrid genome composed of sequences from Tomato yellow leaf curl virus-Mild (TYLCV-Mld) and Hollyhock leaf crumple virus (HoLCrV). A TYLCMLV infectious clone induced leaf curl and yellowing in tomato, leaf curl, crumpling and yellowing in Nicotiana benthamiana and common bean, mild symptoms in N. glutinosa, and a symptomless infection in Datura stramonium. In a field-collected sample from a tomato plant showing the severe symptom phenotype in Mali, TYLCMLV was detected together with a betasatellite, identified as Cotton leaf curl Gezira betasatellite (CLCuGB). Tomato plants co-agroinoculated with TYLCMLV and CLCuGB developed severely stunted and distorted growth and small crumpled leaves. These symptoms were more severe than those induced by TYLCMLV alone, and were similar to the severe symptom phenotype observed in the field in Mali and in other West African countries. TYLCMLV and CLCuGB also induced more severe symptoms than TYLCMLV in the other solanaceous hosts, but not in common bean. The increased symptom severity was associated with hyperplasia of phloem-associated cells, but relatively little increase in TYLCMLV DNA levels. In surveys of tomato virus diseases in West Africa, TYLCMLV was commonly detected in plants with leaf curl and yellow leaf curl symptoms, whereas CLCuGB was infrequently detected and always in association with the severe symptom phenotype. Together, these results indicate that TYLCMLV causes tomato yellow leaf curl disease

  6. Development of plants resistant to Papaya leaf distortion mosaic virus by intergeneric hybridization between Carica papaya and Vasconcellea cundinamarcensis

    PubMed Central

    Tarora, Kazuhiko; Shudo, Ayano; Kawano, Shinji; Yasuda, Keiji; Ueno, Hiroki; Matsumura, Hideo; Urasaki, Naoya

    2016-01-01

    In this study, we confirmed that Vasconcellea cundinamarcensis resists Papaya leaf distortion mosaic virus (PLDMV), and used it to produce intergeneric hybrids with Carica papaya. From the cross between C. papaya and V. cundinamarcensis, we obtained 147 seeds with embryos. Though C. papaya is a monoembryonic plant, multiple embryos were observed in all 147 seeds. We produced 218 plants from 28 seeds by means of embryo-rescue culture. All plants had pubescence on their petioles and stems characteristic of V. cundinamarcensis. Flow cytometry and PCR of 28 plants confirmed they were intergeneric hybrids. To evaluate virus resistance, mechanical inoculation of PLDMV was carried out. The test showed that 41 of 134 intergeneric hybrid plants showed no symptoms and were resistant. The remaining 93 hybrids showed necrotic lesions on the younger leaves than the inoculated leaves. In most of the 93 hybrids, the necrotic lesions enclosed the virus and prevented further spread. These results suggest that the intergeneric hybrids will be valuable material for PLDMV-resistant papaya breeding. PMID:28163589

  7. The P0 gene of Sugarcane yellow leaf virus encodes an RNA silencing suppressor with unique activities

    SciTech Connect

    Mangwende, Tichaona Wang Mingli Borth, Wayne Hu, John Moore, Paul H. Mirkov, T. Erik Albert, Henrik H.

    2009-02-05

    The Sugarcane yellow leaf virus (SCYLV) P0, a member of the highly heterologous proteins of poleroviruses, is a suppressor of posttranscriptional gene silencing (PTGS) and has additional activities not seen in other P0 proteins. The P0 protein in previously tested poleroviruses (Beet western yellows virus and Cucurbit aphid-borne yellows virus), suppresses local, but not systemic, PTGS induced by both sense GFP and inverted repeat GF using its F-box-like domain to mediate destabilization of the Argonaute1 protein. We now report that the SCYLV P0 protein not only suppressed local PTGS induced by sense GFP and inverted repeat GF in Nicotiana benthamiana, but also triggered a dosage dependent cell death phenotype in infiltrated leaves and suppressed systemic sense GFP-PTGS. Deletion of the first 15 N-terminal amino acid residues of SCYLV P0 abolished suppression of both local and systemic PTGS and the induction of cell death. In contrast, only systemic PTGS and cell death were lost when the 15 C-terminal amino acid residues were deleted. We conclude that the 15 C-terminal amino acid residue region of SCYLV P0 is necessary for suppressing systemic PTGS and inducing cell death, but is not required for suppression of local PTGS.

  8. Chilli leaf curl virus-based vector for phloem-specific silencing of endogenous genes and overexpression of foreign genes.

    PubMed

    Kushwaha, Nirbhay Kumar; Chakraborty, Supriya

    2017-03-01

    Geminiviruses are the largest and most devastating group of plant viruses which contain ssDNA as a genetic material. Geminivirus-derived virus-induced gene silencing (VIGS) vectors have emerged as an efficient and simple tool to study functional genomics in various plants. However, previously developed VIGS vectors have certain limitations, owing to their inability to be used in tissue-specific functional study. In the present study, we developed a Chilli leaf curl virus (ChiLCV)-based VIGS vector for its tissue-specific utilization by replacing the coat protein gene (open reading frame (ORF) AV1) with the gene of interest for phytoene desaturase (PDS) of Nicotiana benthamiana. Functional validation of ChiLCV-based VIGS in N. benthamiana resulted in systemic silencing of PDS exclusively in the phloem region of inoculated plants. Furthermore, expression of enhanced green fluorescence protein (EGFP) using the same ChiLCV vector was verified in the phloem region of the inoculated plants. Our results also suggested that, during the early phase of infection, ChiLCV was associated with the phloem region, but at later stage of pathogenesis, it can spread into the adjoining non-vascular tissues. Taken together, the newly developed ChiLCV-based vector provides an efficient and versatile tool, which can be exploited to unveil the unknown functions of several phloem-specific genes.

  9. Development of plants resistant to Papaya leaf distortion mosaic virus by intergeneric hybridization between Carica papaya and Vasconcellea cundinamarcensis.

    PubMed

    Tarora, Kazuhiko; Shudo, Ayano; Kawano, Shinji; Yasuda, Keiji; Ueno, Hiroki; Matsumura, Hideo; Urasaki, Naoya

    2016-12-01

    In this study, we confirmed that Vasconcellea cundinamarcensis resists Papaya leaf distortion mosaic virus (PLDMV), and used it to produce intergeneric hybrids with Carica papaya. From the cross between C. papaya and V. cundinamarcensis, we obtained 147 seeds with embryos. Though C. papaya is a monoembryonic plant, multiple embryos were observed in all 147 seeds. We produced 218 plants from 28 seeds by means of embryo-rescue culture. All plants had pubescence on their petioles and stems characteristic of V. cundinamarcensis. Flow cytometry and PCR of 28 plants confirmed they were intergeneric hybrids. To evaluate virus resistance, mechanical inoculation of PLDMV was carried out. The test showed that 41 of 134 intergeneric hybrid plants showed no symptoms and were resistant. The remaining 93 hybrids showed necrotic lesions on the younger leaves than the inoculated leaves. In most of the 93 hybrids, the necrotic lesions enclosed the virus and prevented further spread. These results suggest that the intergeneric hybrids will be valuable material for PLDMV-resistant papaya breeding.

  10. A begomovirus associated with Ageratum yellow vein disease in Indonesia: evidence for natural recombination between tomato leaf curl Java virus and Ageratum yellow vein virus-[Java].

    PubMed

    Kon, T; Kuwabara, K; Hidayat, S H; Ikegami, M

    2007-01-01

    A begomovirus (2747 nucleotides) and a satellite DNA beta component (1360 nucleotides) have been isolated from Ageratum conyzoides L. plants with yellow vein symptoms growing in Java, Indonesia. The begomovirus is most closely related to Tomato leaf curl Java virus (ToLCJV) (91 and 98% in the total nucleotide and coat protein amino acid sequences, respectively), although the products of ORFs C1 and C4 are more closely related to those of Ageratum yellow vein virus-[Java] (91 and 95% identity, respectively). For this reason, the begomovirus it is considered to be a strain of ToLCJV and is referred to as ToLCJV-Ageratum. The virus probably derives from a recombination event in which nucleotides 2389-2692 of ToLCJV have been replaced with the corresponding region of the AYVV-[Java] genome, which includes the 5' part of the intergenic region and the C1 and C4 ORFs. Infection of A. conyzoides with ToLCJV-Ageratum alone produced no symptoms, but co-infection with DNAbeta induced yellow vein symptoms. Symptoms induced in Nicotiana benthamiana by ToLCJV-Ageratum, ToLCJV and AYVV-[Java] are consistent with the exchange of pathogenicity determinant ORF C4 during recombination.

  11. Transcriptome profiling to discover defense-related genes associated with resistance line ty-5 against Tomato yellow leaf curl virus in tomato

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tomato yellow leaf curl virus (TYLCV), a whitefly-transmitted begomovirus, has caused serious economic losses to tomato crops in the U.S. and around the world. The most effective management would be the use of a TYLCV-resistant tomato cultivar. Several sources of TYLCV resistance genes have been ide...

  12. Field evaluation of yield effects on the U.S.A. heirloom sweet potato cultivars infected by sweet potato leaf curl virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The incidence of Sweet potato leaf curl virus (SPLCV), a Begomovirus, infection of sweetpotato Ipomoea batatas (L.) Lam. (Convolvulaceae) in South Carolina, USA has increased rapidly in recent years. This is likely due to the use of infected propagating materials and the increasing population of it...

  13. Implication of the Whitefly Bemisia tabaci Cyclophilin B Protein in the Transmission of Tomato yellow leaf curl virus

    PubMed Central

    Kanakala, Surapathrudu; Ghanim, Murad

    2016-01-01

    Tomato yellow leaf curl virus (TYLCV) is a single-stranded (ssDNA) begomoviruses that causes severe damage to tomato and several other crops worldwide. TYLCV is exclusively transmitted by the sweetpotato whitefly, Bemisia tabaci in a persistent circulative and propagative manner. Previous studies have shown that the transmission, retention, and circulation of TYLCV in its vector involves interaction with insect and endosymbiont proteins, which aid in the transmission of the virus, or have a protective role in response to the presence of the virus in the insect body. However, only a low number of such proteins have been identified. Here, the role of B. tabaci Cyclophilin B (CypB) in the transmission of TYLCV protein was investigated. Cyclophilins are a large family of cellular prolyl isomerases that have many molecular roles including facilitating protein-protein interactions in the cell. One cyclophilin protein has been implicated in aphid-luteovirus interactions. We demonstrate that the expression of CypB from B. tabaci is altered upon TYLCV acquisition and retention. Further experiments used immunocapture-PCR and co-immunolocalization and demonstrated a specific interaction and colocalization between CypB and TYLCV in the the midgut, eggs, and salivary glands. Membrane feeding of anti-CypB antibodies and TYLCV-infected plants showed a decrease in TYLCV transmission, suggesting a critical role that CypB plays in TYLCV transmission. Further experiments, which used membrane feeding with the CypB inhibitor Cyclosporin A showed decrease in CypB-TYLCV colocalization in the midgut and virus transmission. Altogether, our results indicate that CypB plays an important role in TYLCV transmission by B. tabaci. PMID:27895657

  14. Virus-induced gene silencing of P23k in barley leaf reveals morphological changes involved in secondary wall formation.

    PubMed

    Oikawa, Ai; Rahman, Abidur; Yamashita, Tetsuro; Taira, Hideharu; Kidou, Shin-Ichiro

    2007-01-01

    P23k is a monocot-unique protein that is highly expressed in the scutellum of germinating barley seed. Previous expression analyses suggested that P23k is involved in sugar translocation and/or sugar metabolism. However, the role of P23k in barley physiology remains unclear. Here, to elucidate its physiological function, BSMV-based virus-induced gene silencing (VIGS) of P23k in barley leaves was performed. Expression and localization analyses of P23k mRNA in barley leaves showed up-regulation of P23k transcript with increased photosynthetic activity and the localization of these transcripts to the vascular bundles and sclerenchyma, where secondary wall formation is most active. VIGS of the P23k gene led to abnormal leaf development, asymmetric orientation of main veins, and cracked leaf edges caused by mechanical weakness. In addition, histochemical analyses indicated that the distribution of P23k in leaves coincides with the distribution of cell wall polysaccharides. Considering these results together, it is proposed that P23k is involved in the synthesis of cell wall polysaccharides and contributes to secondary wall formation in barley leaves.

  15. Association of tomato leaf curl New Delhi virus DNA-B with bhendi yellow vein mosaic virus in okra showing yellow vein mosaic disease symptoms.

    PubMed

    Venkataravanappa, V; Lakshminarayana Reddy, C N; Jalali, S; Krishna Reddy, M

    2015-06-01

    Okra samples showing yellow vein mosaic, vein twisting and bushy appearance were collected from different locations of India during the surveys conducted between years 2005-2009. The dot blot and PCR detection revealed that 75.14% of the samples were associated with monopartite begomovirus and remaining samples with bipartite virus. Whitefly transmission was established for three samples representing widely separated geographical locations which are negative to betasatellites and associated with DNA-B. Genome components of these three representative isolates were cloned and sequenced. The analysis of DNA-A-like sequence revealed that three begomovirus isolates shared more than 93% nucleotide sequence identity with bhendi yellow vein mosaic virus from India (BYVMV), a monopartite begomovirus species that was reported previously as causative agent of bhendi yellow mosaic disease in association of bhendi yellow vein mosaic betasatellite. Further, the DNA-B-like sequences associated with the three virus isolates shared no more than 90% sequence identity with tomato leaf curl New Delhi virus (ToLCNDV). Analyses of putative iteron-binding sequence required for trans-replication suggests that begomovirus sequences shared compatible rep-binding iterons with DNA-B of ToLCNDV. Our data suggest that the monopartite begomovirus associated with okra yellow vein disease has captured DNA-B of ToLCNDV to infect okra. Widespread distribution of the complex shows the increasing trend of the capturing of DNA-B of ToLCNDV by monopartite begomoviruses in the Indian subcontinent. The recombination analysis showed that the DNA-A might have been derived from the inter-specific recombination of begomoviruses, while DNA-B was derived from the ToLCNDV infecting different hosts.

  16. Complete genome sequence of an isolate of papaya leaf distortion mosaic virus from commercialized PRSV-resistant transgenic papaya in China.

    PubMed

    Tuo, D; Shen, W; Yan, P; Li, Ch; Gao, L; Li, X; Li, H; Zhou, P

    2013-01-01

    Papaya leaf distortion mosaic virus is highly destructive to commercial papaya production. Here, the complete genome sequence was determined for an isolate of papaya leaf distortion mosaic virus, designated PLDMV-DF, infecting the commercialized papaya ringspot virus (PRSV)-resistant transgenic papaya from China. Excluding the 3'-poly (A) tail, the sequence shares high sequence identity to several PLDMV isolates from Taiwan and Japan and is phylogenetically most closely related to the isolate from Japan. Infection of PLDMV-DF in transgenic PRSV-resistant papaya may indicate emergence of this disease in genetically engineered plants. The reported sequence for this isolate may help generate bi-transgenic papaya resistant to PRSV and PLDMV.

  17. Genetic diversity and distribution of a distinct strain of Chili leaf curl virus and associated betasatellite infecting tomato and pepper in Oman.

    PubMed

    Khan, Akhtar J; Akhtar, Sohail; Al-Zaidi, Amal M; Singh, Achuit K; Briddon, Rob W

    2013-10-01

    Tomato and pepper are widely grown in Oman for local consumption. A countrywide survey was conducted during 2010-2011 to collect samples and assess the diversity of begomoviruses associated with leaf curl disease of tomato and pepper. A virus previously only identified on the Indian subcontinent, chili leaf curl virus (ChLCV), was found associated with tomato and pepper diseases in all vegetable grown areas of Oman. Some of the infected plant samples were also found to contain a betasatellite. A total of 19 potentially full-length begomovirus and eight betasatellite clones were sequenced. The begomovirus clones showed >96% nucleotide sequence identity, showing them to represent a single species. Comparisons to sequences available in the databases showed the highest levels of nucleotide sequence identity (88.0-91.1%) to isolates of the "Pakistan" strain of ChLCV (ChLCV-PK), indicating the virus from Oman to be a distinct strain, for which the name Oman strain (ChLCV-OM) is proposed. An analysis for recombination showed ChLCV-OM likely to have originated by recombination between ChLCV-PK (the major parent), pepper leaf curl Lahore virus and a third strain of ChLCV. The betasatellite sequences obtained were shown to have high levels of identity to isolates of tomato leaf curl betasatellite (ToLCB) previous shown to be present in Oman. For the disease in tomato Koch's postulates were satisfied by Agrobacterium-mediated inoculation of virus and betasatellites clones. This showed the symptoms induced by the virus in the presence of the betasatellite to be enhanced, although viral DNA levels were not affected. ChLCV-OM is the fourth begomovirus identified in tomato in Oman and the first in Capsicum. The significance of these findings is discussed.

  18. Development and validation of a multiplex reverse transcription quantitative PCR (RT-qPCR) assay for the rapid detection of Citrus tristeza virus, Citrus psorosis virus, and Citrus leaf blotch virus.

    PubMed

    Osman, Fatima; Hodzic, Emir; Kwon, Sun-Jung; Wang, Jinbo; Vidalakis, Georgios

    2015-08-01

    A single real-time multiplex reverse transcription quantitative polymerase chain reaction (RT-qPCR) assay for the simultaneous detection of Citrus tristeza virus (CTV), Citrus psorosis virus (CPsV), and Citrus leaf blotch virus (CLBV) was developed and validated using three different fluorescently labeled minor groove binding qPCR probes. To increase the detection reliability, coat protein (CP) genes from large number of different isolates of CTV, CPsV and CLBV were sequenced and a multiple sequence alignment was generated with corresponding CP sequences from the GenBank and a robust multiplex RT-qPCR assay was designed. The capacity of the multiplex RT-qPCR assay in detecting the viruses was compared to singleplex RT-qPCR designed specifically for each virus and was assessed using multiple virus isolates from diverse geographical regions and citrus species as well as graft-inoculated citrus plants infected with various combination of the three viruses. No significant difference in detection limits was found and specificity was not affected by the inclusion of the three assays in a multiplex RT-qPCR reaction. Comparison of the viral load for each virus using singleplex and multiplex RT-qPCR assays, revealed no significant differences between the two assays in virus detection. No significant difference in Cq values was detected when using one-step and two-step multiplex RT-qPCR detection formats. Optimizing the RNA extraction technique for citrus tissues and testing the quality of the extracted RNA using RT-qPCR targeting the cytochrome oxidase citrus gene as an RNA specific internal control proved to generate better diagnostic assays. Results showed that the developed multiplex RT-qPCR can streamline viruses testing of citrus nursery stock by replacing three separate singleplex assays, thus reducing time and labor while retaining the same sensitivity and specificity. The three targeted RNA viruses are regulated pathogens for California's mandatory "Section 3701

  19. Rolling-circle amplification of Torque teno virus (TTV) complete genomes from human and swine sera and identification of a novel swine TTV genogroup.

    PubMed

    Niel, Christian; Diniz-Mendes, Leonardo; Devalle, Sylvie

    2005-05-01

    Multiply primed rolling-circle amplification is a novel technology that uses bacteriophage phi29 DNA polymerase to amplify circular DNA molecules, without the need for prior knowledge of their sequences. In an attempt to detect Torque teno virus (TTV), rolling-circle amplification was used to amplify DNA extracted from eight human and four pig serum samples. All samples gave high molecular weight (>30 kb) amplification products. By restriction endonuclease digestion, these products generated DNA fragments whose sizes were consistent with those of human TTV (3.8 kb) and swine TTV (Sd-TTV; 2.9 kb) genomes. Two TTV isolates derived from a single AIDS patient, as well as two Sd-TTV isolates derived from a single pig, were characterized by complete nucleotide sequencing. One of the Sd-TTV isolates showed very low (43-45 %) nucleotide sequence similarity to the other Sd-TTV isolate and to the prototype isolate Sd-TTV31, and could be considered the prototype of a novel genogroup.

  20. Rapid accumulation and low degradation: key parameters of Tomato yellow leaf curl virus persistence in its insect vector Bemisia tabaci.

    PubMed

    Becker, Nathalie; Rimbaud, Loup; Chiroleu, Frédéric; Reynaud, Bernard; Thébaud, Gaël; Lett, Jean-Michel

    2015-12-02

    Of worldwide economic importance, Tomato yellow leaf curl virus (TYLCV, Begomovirus) is responsible for one of the most devastating plant diseases in warm and temperate regions. The DNA begomoviruses (Geminiviridae) are transmitted by the whitefly species complex Bemisia tabaci. Although geminiviruses have long been described as circulative non-propagative viruses, observations such as long persistence of TYLCV in B. tabaci raised the question of their possible replication in the vector. We monitored two major TYLCV strains, Mild (Mld) and Israel (IL), in the invasive B. tabaci Middle East-Asia Minor 1 cryptic species, during and after the viral acquisition, within two timeframes (0-144 hours or 0-20 days). TYLCV DNA was quantified using real-time PCR, and the complementary DNA strand of TYLCV involved in viral replication was specifically quantified using anchored real-time PCR. The DNA of both TYLCV strains accumulated exponentially during acquisition but remained stable after viral acquisition had stopped. Neither replication nor vertical transmission were observed. In conclusion, our quantification of the viral loads and complementary strands of both Mld and IL strains of TYLCV in B. tabaci point to an efficient accumulation and preservation mechanism, rather than to a dynamic equilibrium between replication and degradation.

  1. Rapid accumulation and low degradation: key parameters of Tomato yellow leaf curl virus persistence in its insect vector Bemisia tabaci

    PubMed Central

    Becker, Nathalie; Rimbaud, Loup; Chiroleu, Frédéric; Reynaud, Bernard; Thébaud, Gaël; Lett, Jean-Michel

    2015-01-01

    Of worldwide economic importance, Tomato yellow leaf curl virus (TYLCV, Begomovirus) is responsible for one of the most devastating plant diseases in warm and temperate regions. The DNA begomoviruses (Geminiviridae) are transmitted by the whitefly species complex Bemisia tabaci. Although geminiviruses have long been described as circulative non-propagative viruses, observations such as long persistence of TYLCV in B. tabaci raised the question of their possible replication in the vector. We monitored two major TYLCV strains, Mild (Mld) and Israel (IL), in the invasive B. tabaci Middle East-Asia Minor 1 cryptic species, during and after the viral acquisition, within two timeframes (0–144 hours or 0–20 days). TYLCV DNA was quantified using real-time PCR, and the complementary DNA strand of TYLCV involved in viral replication was specifically quantified using anchored real-time PCR. The DNA of both TYLCV strains accumulated exponentially during acquisition but remained stable after viral acquisition had stopped. Neither replication nor vertical transmission were observed. In conclusion, our quantification of the viral loads and complementary strands of both Mld and IL strains of TYLCV in B. tabaci point to an efficient accumulation and preservation mechanism, rather than to a dynamic equilibrium between replication and degradation. PMID:26625871

  2. Inhibition of binding of tomato yellow leaf curl virus rep to its replication origin by artificial zinc-finger protein.

    PubMed

    Mori, Tomoaki; Takenaka, Kosuke; Domoto, Fumiya; Aoyama, Yasuhiro; Sera, Takashi

    2013-06-01

    Previously we demonstrated that inhibition of replication-associated protein (Rep) binding to its replication origin by artificial zinc-finger proteins (AZPs) is a powerful method to prevent plant virus infection in vivo. In the present study, we applied the AZP technology to Tomato yellow leaf curl virus (TYLCV), which is a limiting factor in tomato cultivation worldwide. First, we determined 5'-ATCGGTGT ATCGGTGT-3' in the 195-bp intergenic region of the TYLCV-Israel strain, a strain reported first among TYLCV strains, as the Rep-binding site by gel shift assays. We then constructed a 6-finger AZP that bound to a 19-bp DNA including the Rep-binding site. We demonstrated that the binding affinity of the AZP was >1,000-fold greater than that of Rep and that the AZP inhibited Rep binding completely in vitro. Because the binding capability of the AZP was same as that of the AZP previously designed for geminivirus-resistant Arabidopsis thaliana, we predict that the present AZP will prevent TYLCV infection in vivo.

  3. Functional Characterization of a Bidirectional Plant Promoter from Cotton Leaf Curl Burewala Virus Using an Agrobacterium-Mediated Transient Assay

    PubMed Central

    Ashraf, Muhammad Aleem; Shahid, Ahmad Ali; Rao, Abdul Qayyum; Bajwa, Kamran Shehzad; Husnain, Tayyab

    2014-01-01

    The C1 promoter expressing the AC1 gene, and V1 promoter expressing the AV1 gene are located in opposite orientations in the large intergenic region of the Cotton leaf curl Burewala virus (CLCuBuV) genome. Agro-infiltration was used to transiently express putative promoter constructs in Nicotiana tabacum and Gossypium hirsutum leaves, which was monitored by a GUS reporter gene, and revealed that the bidirectional promoter of CLCuBuV transcriptionally regulates both the AC1 and AV1 genes. The CLCuBuV C1 gene promoter showed a strong, consistent transient expression of the reporter gene (GUS) in N. tabacum and G. hirsutum leaves and exhibited GUS activity two- to three-fold higher than the CaMV 35S promoter. The CLCuBuV bidirectional genepromoter is a nearly constitutive promoter that contains basic conserved elements. Many cis-regulatory elements (CREs) were also analyzed within the bidirectional plant promoters of CLCuBuV and closely related geminiviruses, which may be helpful in understanding the transcriptional regulation of both the virus and host plant. PMID:24424501

  4. Functional Characterization of a Strong Bi-directional Constitutive Plant Promoter Isolated from Cotton Leaf Curl Burewala Virus

    PubMed Central

    Khan, Zainul A.; Abdin, Malik Z.; Khan, Jawaid A.

    2015-01-01

    Cotton leaf curl Burewala virus (CLCuBuV), belonging to the genus Begomovirus, possesses single-stranded monopartite DNA genome. The bidirectional promoters representing Rep and coat protein (CP) genes of CLCuBuV were characterized and their efficacy was assayed. Rep and CP promoters of CLCuBuV and 35S promoter of Cauliflower mosaic virus (CaMV) were fused with β-glucuronidase (GUS) and green fluorescent protein (GFP) reporter genes. GUS activity in individual plant cells driven by Rep, CP and 35S promoters was estimated using real-time PCR and fluorometric GUS assay. Histochemical staining of GUS in transformed tobacco (Nicotiana tabacum cv. Xanthi) leaves showed highest expression driven by Rep promoter followed by 35S promoter and CP promoter. The expression level of GUS driven by Rep promoter in transformed tobacco plants was shown to be two to four-fold higher than that of 35S promoter, while the expression by CP promoter was slightly lower. Further, the expression of GFP was monitored in agroinfiltrated leaves of N. benthamiana, N. tabacum and cotton (Gossypium hirsutum) plants using confocal laser scanning microscopy. Rep promoter showed strong consistent transient expression in tobacco and cotton leaves as compared to 35S promoter. The strong constitutive CLCuBuV Rep promoter developed in this study could be very useful for high level expression of transgenes in a wide variety of plant cells. PMID:25799504

  5. Effects of Isaria fumosorosea on TYLCV (Tomato Yellow Leaf Curl Virus) Accumulation and Transmitting Capacity of Bemisia tabaci

    PubMed Central

    2016-01-01

    Tomato yellow leaf curl virus (TYLCV) is transmitted by the Bemisia tabaci pest Middle East-Asia Minor 1 (MEAM1) in China. Isaria fumosorosea is a fungal pathogen of B. tabaci. However, the effects of fungal infection on TYLCV expression and transmission by MEAM1 are unclear. In this study, potted tomatoes containing second instar nymphs of MEAM1 were treated with I. fumosorosea IfB01 strain and the relationship between fungal infection in MEAM1 and its TYLCV transmission capacity was investigated. The results indicated that a significantly (p < 0.05) decreased incidence of transmission of TYLCV-infected plants (ITYPs) transmitted by second instar nymphs of MEAM1 infected with fungus. Further, we found a negative correlation between fungal conidial concentrations and eclosion rates of MEAM1, and a positive correlation between ITYPs and eclosion. In addition, when each plant was exposed to three adults treated with fungus, a significantly decreased transmission of TYLCV (TYTE) was observed in the infected group. However, the incidence of TYLCV-carrying MEAM1 adults (ITYAs) was not significantly different in the infected and control groups (p < 0.05). Nevertheless, a significant decrease in viral accumulation using TYLCV AC2 gene as a marker was observed in the fungus-infected MEAM1. In conclusion, the results suggested that I. fumosorosea infection decreases TYLCV accumulation in MEAM1 and subsequently reduces its transmission. Our study provides new insights into the relationship between host plant, plant virus, insect vector, and entomopathogenic fungus. PMID:27716852

  6. Tomato plant cell death induced by inhibition of HSP90 is alleviated by Tomato yellow leaf curl virus infection.

    PubMed

    Moshe, Adi; Gorovits, Rena; Liu, Yule; Czosnek, Henryk

    2016-02-01

    To ensure a successful long-term infection cycle, begomoviruses must restrain their destructive effect on host cells and prevent drastic plant responses, at least in the early stages of infection. The monopartite begomovirus Tomato yellow leaf curl virus (TYLCV) does not induce a hypersensitive response and cell death on whitefly-mediated infection of virus-susceptible tomato plants until diseased tomatoes become senescent. The way in which begomoviruses evade plant defences and interfere with cell death pathways is still poorly understood. We show that the chaperone HSP90 (heat shock protein 90) and its co-chaperone SGT1 (suppressor of the G2 allele of Skp1) are involved in the establishment of TYLCV infection. Inactivation of HSP90, as well as silencing of the Hsp90 and Sgt1 genes, leads to the accumulation of damaged ubiquitinated proteins and to a cell death phenotype. These effects are relieved under TYLCV infection. HSP90-dependent inactivation of 26S proteasome degradation and the transcriptional activation of the heat shock transcription factors HsfA2 and HsfB1 and of the downstream genes Hsp17 and Apx1/2 are suppressed in TYLCV-infected tomatoes. Following suppression of the plant stress response, TYLCV can replicate and accumulate in a permissive environment.

  7. Progressive aggregation of Tomato yellow leaf curl virus coat protein in systemically infected tomato plants, susceptible and resistant to the virus.

    PubMed

    Gorovits, Rena; Moshe, Adi; Kolot, Mikhail; Sobol, Iris; Czosnek, Henryk

    2013-01-01

    Tomato yellow leaf curl virus (TYLCV) coat protein (CP) accumulated in tomato leaves during infection. The CP was immuno-detected in the phloem associated cells. At the early stages of infection, punctate signals were detected in the cytoplasm, while in the later stages aggregates of increasing size were localized in cytoplasm and nuclei. Sedimentation of protein extracts through sucrose gradients confirmed that progress of infection was accompanied by the formation of CP aggregates of increasing size. Genomic ssDNA was found in the cytoplasm and in the nucleus, while the dsDNA replicative form was exclusively associated with the nucleus. CP-DNA complexes were detected by immuno-capture PCR in nuclear and cytoplasmic large aggregates. Nuclear aggregates contained infectious particles transmissible to test plants by whiteflies. In contrast to susceptible tomatoes, the formation of large CP aggregates in resistant plants was delayed. By experimentally changing the level of resistance/susceptibility of plants, we showed that maintenance of midsized CP aggregates was associated with resistance, while large aggregates where characteristic of susceptibility. We propose that sequestering of virus CP into midsized aggregates and retarding the formation of large insoluble aggregates containing infectious particles is part of the response of resistant plants to TYLCV.

  8. Microsatellite Diversity of Soybean Genotypes Differing in Bean Pod Mottle Virus Leaf Symptom

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean, Glycine max (L.) Merr, is the most important source of vegetable oil and protein meal in the world. Bean pod mottle virus (BPMV) is a threat to soybean yield and productivity in most soybean growing states of the USA. In the absence of complete resistance to BPMV, partial resistance of so...

  9. Effect of Raspberry bushy dwarf virus, Raspberry leaf mottle virus, and Raspberry latent virus on plant growth and fruit crumbliness in ‘Meeker’ red Raspberry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Raspberry crumbly fruit in red raspberry (Rubus idaeus L.), widespread in the Pacific Northwest of the United States and British Columbia, Canada, is most commonly caused by a virus infection. Raspberry bushy dwarf virus (RBDV) has long been attributed as the causal agent of the disease. Recently, t...

  10. How to pattern a leaf

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leaf development presents a tremendous resource for tackling the question of patterning in biology. Leaves can be simple or highly dissected. They may have elaborated parts such as the tendrils of a pea leaf or the rolled blade of a carnivorous pitcher plant. Despite the variation in size, shape, an...

  11. A developmentally regulated lipocalin-like gene is overexpressed in Tomato yellow leaf curl virus-resistant tomato plants upon virus inoculation, and its silencing abolishes resistance.

    PubMed

    Sade, Dagan; Eybishtz, Assaf; Gorovits, Rena; Sobol, Iris; Czosnek, Henryk

    2012-10-01

    To discover genes involved in tomato resistance to Tomato yellow leaf curl virus (TYLCV), we previously compared cDNA libraries from susceptible (S) and resistant (R) tomato lines. Among the genes preferentially expressed in R plants and upregulated by TYLCV infection was a gene encoding a lipocalin-like protein. This gene was termed Solanum lycopersicum virus resistant/susceptible lipocalin (SlVRSLip). The SlVRSLip structural gene sequence of R and S plants was identical. SlVRSLip was expressed in leaves during a 15-day window starting about 40 days after sowing (20 days after planting). SlVRSLip was upregulated by Bemisia tabaci (the TYLCV vector) feeding on R plant leaves, and even more strongly upregulated following whitefly-mediated TYLCV inoculation. Silencing of SlVRSLip in R plants led to the collapse of resistance upon TYLCV inoculation and to a necrotic response along the stem and petioles accompanied by ROS production. Contrary to previously identified tomato lipocalin gene DQ222981, SlVRSLip was not regulated by cold, nor was it regulated by heat or salt. The expression of SlVRSLip was inhibited in R plants in which the hexose transporter gene LeHT1 was silenced. In contrast, the expression of LeHT1 was not inhibited in SlVRSLip-silenced R plants. Hence, in the hierarchy of the gene network conferring TYLCV resistance, SlVRSLip is downstream of LeHT1. Silencing of another gene involved in resistance, a Permease-I like protein, did not affect the expression of SlVRSLip and LeHT1; expression of the Permease was not affected by silencing SlVRSLip or LeHT1, suggesting that it does not belong to the same network. The triple co-silencing of SlVRSLip, LeHT1 and Permease provoked an immediate cessation of growth of R plants upon infection and the accumulation of large amounts of virus. SlVRSLip is the first lipocalin-like gene shown to be involved in resistance to a plant virus.

  12. Colorimetric monitoring of rolling circle amplification for detection of H5N1 influenza virus using metal indicator.

    PubMed

    Hamidi, Seyed Vahid; Ghourchian, Hedayatollah

    2015-10-15

    A new colorimetric method for monitoring of rolling circle amplification was developed. At first H5N1 target hybrids with padlock probe (PLP) and then PLP is circularized upon the action of T4 ligase enzyme. Subsequently, the circular probe is served as a template for hyperbranched rolling circle amplification (HRCA) by utilizing Bst DNA polymerase enzyme. By improving the reaction, pyrophosphate is produced via DNA polymerization and chelates the Mg(2+) in the buffer solution. This causes change in solution color in the presence of hydroxy naphthol blue (HNB) as a metal indicator. By using pH shock instead of heat shock and isothermal RCA reaction not only the procedure becomes easier, but also application of HNB for colorimetric detection of RCA reaction further simplifies the assay. The responses of the biosensor toward H5N1 were linear in the concentration range from 0.16 to 1.20 pM with a detection limit of 28 fM.

  13. Phylogenetic analysis and inflow route of Tomato yellow leaf curl virus (TYLCV) and Bemisia tabaci in Korea.

    PubMed

    Lee, Hyejung; Song, Woogeun; Kwak, Hae-Ryun; Kim, Jae-Deok; Park, Jungan; Auh, Chung-Kyoon; Kim, Dae-Hyun; Lee, Kyeong-Yeoll; Lee, Sukchan; Choi, Hong-Soo

    2010-11-01

    Tomato yellow leaf curl virus (TYLCV) is a member of the genus Begomovirus of the family Geminiviridae, members of which are characterized by closed circular single-stranded DNA genomes of 2.7-2.8 kb in length, and include viruses transmitted by the Bemisia tabaci whitefly. No reports of TYLCV in Korea are available prior to 2008, after which TYLCV spread rapidly to most regions of the southern Korean peninsula (Gyeongsang-Do, Jeolla-Do and Jeju-Do). Fifty full sequences of TYLCV were analyzed in this study, and the AC1, AV1, IR, and full sequences were analyzed via the muscle program and bayesian analysis. Phylogenetic analysis demonstrated that the Korea TYLCVs were divided into two subgroups. The TYLCV Korea 1 group (Masan) originated from TYLCV Japan (Miyazaki) and the TYLCV Korea 2 group (Jeju/Jeonju) from TYLCV Japan (Tosa/Haruno). A B. tabaci phylogenetic tree was constructed with 16S rRNA and mitochondria cytochrome oxidase I (MtCOI) sequences using the muscle program and MEGA 4.0 in the neighbor-joining algorithm. The sequence data of 16S rRNA revealed that Korea B. tabaci was closely aligned to B. tabaci isolated in Iran and Nigeria. The Q type of B. tabaci, which was originally identified as a viruliferous insect in 2008, was initially isolated in Korea as a non-viruliferous insect in 2005. Therefore, we suggest that two TYLCV Japan isolates were introduced to Korea via different routes, and then transmitted by native B. tabaci.

  14. Discovering Host Genes Involved in the Infection by the Tomato Yellow Leaf Curl Virus Complex and in the Establishment of Resistance to the Virus Using Tobacco Rattle Virus-based Post Transcriptional Gene Silencing

    PubMed Central

    Czosnek, Henryk; Eybishtz, Assaf; Sade, Dagan; Gorovits, Rena; Sobol, Iris; Bejarano, Eduardo; Rosas-Díaz, Tábata; Lozano-Durán, Rosa

    2013-01-01

    The development of high-throughput technologies allows for evaluating gene expression at the whole-genome level. Together with proteomic and metabolomic studies, these analyses have resulted in the identification of plant genes whose function or expression is altered as a consequence of pathogen attacks. Members of the Tomato yellow leaf curl virus (TYLCV) complex are among the most important pathogens impairing production of agricultural crops worldwide. To understand how these geminiviruses subjugate plant defenses, and to devise counter-measures, it is essential to identify the host genes affected by infection and to determine their role in susceptible and resistant plants. We have used a reverse genetics approach based on Tobacco rattle virus-induced gene silencing (TRV-VIGS) to uncover genes involved in viral infection of susceptible plants, and to identify genes underlying virus resistance. To identify host genes with a role in geminivirus infection, we have engineered a Nicotiana benthamiana line, coined 2IRGFP, which over-expresses GFP upon virus infection. With this system, we have achieved an accurate description of the dynamics of virus replication in space and time. Upon silencing selected N. benthamiana genes previously shown to be related to host response to geminivirus infection, we have identified eighteen genes involved in a wide array of cellular processes. Plant genes involved in geminivirus resistance were studied by comparing two tomato lines: one resistant (R), the other susceptible (S) to the virus. Sixty-nine genes preferentially expressed in R tomatoes were identified by screening cDNA libraries from infected and uninfected R and S genotypes. Out of the 25 genes studied so far, the silencing of five led to the total collapse of resistance, suggesting their involvement in the resistance gene network. This review of our results indicates that TRV-VIGS is an exquisite reverse genetics tool that may provide new insights into the molecular

  15. Tomato yellow leaf curl virus differentially influences plant defence responses to a vector and a non-vector herbivore.

    PubMed

    Su, Qi; Mescher, Mark C; Wang, Shaoli; Chen, Gong; Xie, Wen; Wu, Qingjun; Wang, Wenkai; Zhang, Youjun

    2016-03-01

    Plants frequently engage in simultaneous interactions with diverse classes of biotic antagonists. Differential induction of plant defence pathways by these antagonists, and interactions between pathways, can have important ecological implications; however, these effects are currently not well understood. We explored how Tomato yellow leaf curl virus (TYLCV) influenced the performance of its vector (Bemisia tabaci) and a non-vector herbivore (Tetranychus urticae) occurring separately or together on tomato plants (Solanum lycopersicum). TYLCV enhanced the performance of B. tabaci, although this effect was statistically significant only in the absence of T. urticae, which adversely affected B. tabaci performance regardless of infection status. In contrast, the performance of T. urticae was enhanced (only) by the combined presence of TYLCV and B. tabaci. Analyses of phytohormone levels and defence gene expression in wild-type tomatoes and various plant-defence mutants indicate that the enhancement of herbivore performance (for each species) entails the disruption of downstream defences in the jasmonic acid (JA) pathway. For T. urticae, this disruption appears to involve antagonistic effects of salicylic acid (SA), which is cumulatively induced to high levels by B. tabaci and TYLCV. In contrast, TYLCV was found to suppress JA-mediated responses to B. tabaci via mechanisms independent of SA.

  16. Tomato yellow leaf curl virus infection mitigates the heat stress response of plants grown at high temperatures.

    PubMed

    Ghandi, Anfoka; Adi, Moshe; Lilia, Fridman; Linoy, Amrani; Or, Rotem; Mikhail, Kolot; Mouhammad, Zeidan; Henryk, Czosnek; Rena, Gorovits

    2016-01-21

    Cultured tomatoes are often exposed to a combination of extreme heat and infection with Tomato yellow leaf curl virus (TYLCV). This stress combination leads to intense disease symptoms and yield losses. The response of TYLCV-susceptible and resistant tomatoes to heat stress together with viral infection was compared. The plant heat-stress response was undermined in TYLCV infected plants. The decline correlated with the down-regulation of heat shock transcription factors (HSFs) HSFA2 and HSFB1, and consequently, of HSF-regulated genes Hsp17, Apx1, Apx2 and Hsp90. We proposed that the weakened heat stress response was due to the decreased capacity of HSFA2 to translocate into the nuclei of infected cells. All the six TYLCV proteins were able to interact with tomato HSFA2 in vitro, moreover, coat protein developed complexes with HSFA2 in nuclei. Capturing of HSFA2 by viral proteins could suppress the transcriptional activation of heat stress response genes. Application of both heat and TYLCV stresses was accompanied by the development of intracellular large protein aggregates containing TYLCV proteins and DNA. The maintenance of cellular chaperones in the aggregated state, even after recovery from heat stress, prevents the circulation of free soluble chaperones, causing an additional decrease in stress response efficiency.

  17. Correlation of meteorological parameters and remotely sensed normalized difference vegetation index (NDVI) with cotton leaf curl virus (CLCV) in Multan

    NASA Astrophysics Data System (ADS)

    Ahmed, A.; Akhtar, A.; Khalid, B.; Shamim, A.

    2013-06-01

    Climate change and weather has a profound effect on the spread of Cotton Leaf Curl Virus (CLCV) which is transmitted by whitefly. Climate change is altering temperature and precipitation patterns, resulting in the shift of some insect/pest from small population to large population thus effecting crops yield. To find out the relationship between the weather conditions, outburst of CLCV and changes in Normalized Difference Vegetation Index (NDVI) values due to the outburst of CLCV, a study was carried out for tehsil Multan. Data was acquired for the months of June, July, August and September for the year 2010. Regression analysis between CLCV and meteorological conditions as well as between CLCV and NDVI was performed. Meteorological parameters included temperature, humidity, precipitation, cloud cover, wind direction, pan evaporation and sunshine hours. NDVI values were calculated from SPOT satellite imagery (1km) using ArcMap10 and WinDisp v5.1. Correlation coefficients obtained in most of the cases were acceptable however the significance F and P-value were higher than their critical value at 95% level of significance. Therefore significant correlation was found only between CLCV and temperature and between CLCV and PAN evaporation during the month of July.

  18. Synthesis and biological activity evaluation of novel amino acid derivatives as potential elicitors against Tomato yellow leaf curl virus.

    PubMed

    Deng, Yufang; He, Shun; Geng, Qianqian; Duan, Yongheng; Guo, Mingcheng; Li, Jianqiang; Cao, Yongsong

    2015-12-01

    Disease caused by Tomato yellow leaf curl virus (TYLCV) brings serious production losses of cultivated tomato worldwide. In our previous study, two novel amino acid derivatives exerted satisfactory antiviral activities against TYLCV. In this study, the variation of TYLCV, the transcriptional expression level of Ty-1 and the enzyme activities of POD and PPO in tomato were monitored after treatment with two amino acid derivatives to illustrate the antiviral mechanism. The results showed the symptom severity caused by TYLCV was reduced significantly by two compounds and was associated with the inhibition of viral DNA level at the early stage. Among three levels of concentration, the highest inhibition rate of CNBF-His was 40.66% at 1000 mg/L, for CNBF-Asn, the highest inhibition rate was 36.26% at 2000 mg/L 30 days post-inoculation. Two compounds could also enhance the activities of PPO and POD and the transcriptional expression level of Ty-1 which correlates with plant resistance in tomato. In the field test, two compounds increased the yields of tomato and the maximum increase of yield was 37.66%. This is the first report of novel amino acid derivatives inducing resistance in tomato plant against TYLCV. It is suggested that amino acid derivatives have the potential to be an effective approach against TYLCV in tomato plant.

  19. Improved rolling circle amplification (RCA) of hepatitis B virus (HBV) relaxed-circular serum DNA (RC-DNA).

    PubMed

    Martel, Nora; Gomes, Selma A; Chemin, Isabelle; Trépo, Christian; Kay, Alan

    2013-11-01

    For functional analysis of HBV isolates, epidemiological studies and correct identification of recombinant genomes, the amplification of complete genomes is necessary. A method for completely in vitro amplification of full-length HBV genomes starting from serum RC-DNA is described. This uses in vitro completion/ligation of plus-strand HBV RC-DNA and amplification using Rolling-Circle Amplification, eventually followed by a genomic PCR. The method can amplify complete HBV genomes from sera with viral loads ranging from >1.0E+8 IU/ml down to 1.0E+3 IU/ml. The method can be applied to archived sera that have undergone long-term storage or to archived DNA serum extracts. The genomes can easily be cloned. HBV genotypes A-G can all be amplified with no apparent problems. A recombinant subgenotype A3/genotype E genome was identified and fully sequenced.

  20. Real-time PCR protocols for the quantification of the begomovirus tomato yellow leaf curl Sardinia virus in tomato plants and in its insect vector.

    PubMed

    Noris, Emanuela; Miozzi, Laura

    2015-01-01

    Tomato yellow leaf curl Sardinia virus (TYLCSV) (Geminiviridae) is an important pathogen, transmitted by the whitefly Bemisia tabaci, that severely affects the tomato production in the Mediterranean basin. Here, we describe real-time PCR protocols suitable for relative and absolute quantification of TYLCSV in tomato plants and in whitefly extracts. Using primers and probe specifically designed for TYLCSV, the protocols for relative quantification allow to compare the amount of TYLCSV present in different plant or whitefly samples, normalized to the amount of DNA present in each sample using endogenous tomato or Bemisia genes as internal references. The absolute quantification protocol allows to calculate the number of genomic units of TYLCSV over the genomic units of the plant host (tomato), with a sensitivity of as few as ten viral genome copies per sample. The described protocols are potentially suitable for several applications, such as plant breeding for resistance, analysis of virus replication, and virus-vector interaction studies.

  1. Viruses roll the dice: the stochastic behavior of viral genome molecules accelerates viral adaptation at the cell and tissue levels.

    PubMed

    Miyashita, Shuhei; Ishibashi, Kazuhiro; Kishino, Hirohisa; Ishikawa, Masayuki

    2015-03-01

    Recent studies on evolutionarily distant viral groups have shown that the number of viral genomes that establish cell infection after cell-to-cell transmission is unexpectedly small (1-20 genomes). This aspect of viral infection appears to be important for the adaptation and survival of viruses. To clarify how the number of viral genomes that establish cell infection is determined, we developed a simulation model of cell infection for tomato mosaic virus (ToMV), a positive-strand RNA virus. The model showed that stochastic processes that govern the replication or degradation of individual genomes result in the infection by a small number of genomes, while a large number of infectious genomes are introduced in the cell. It also predicted two interesting characteristics regarding cell infection patterns: stochastic variation among cells in the number of viral genomes that establish infection and stochastic inequality in the accumulation of their progenies in each cell. Both characteristics were validated experimentally by inoculating tobacco cells with a library of nucleotide sequence-tagged ToMV and analyzing the viral genomes that accumulated in each cell using a high-throughput sequencer. An additional simulation model revealed that these two characteristics enhance selection during tissue infection. The cell infection model also predicted a mechanism that enhances selection at the cellular level: a small difference in the replication abilities of coinfected variants results in a large difference in individual accumulation via the multiple-round formation of the replication complex (i.e., the replication machinery). Importantly, this predicted effect was observed in vivo. The cell infection model was robust to changes in the parameter values, suggesting that other viruses could adopt similar adaptation mechanisms. Taken together, these data reveal a comprehensive picture of viral infection processes including replication, cell-to-cell transmission, and evolution

  2. Introgression of genes for cotton leaf curl virus resistance and increased fiber strength from Gossypium stocksii into upland cotton (G. hirsutum).

    PubMed

    Nazeer, W; Ahmad, S; Mahmood, K; Tipu, A L; Mahmood, A; Zhou, B

    2014-02-21

    Cotton leaf curl virus disease is a major hurdle for successful cotton production in Pakistan. There has been considerable economic loss due to this disease during the last decade. It would be desirable to have cotton varieties resistant to this disease. We explored the possibility of transferring virus resistant genes from the wild species Gossypium stocksii into MNH-786, a cultivar of G. hirsutum. Hybridization was done under field condition at the Cotton Research Station, Multan, during 2010-11. Boll shedding was controlled by application of exogenous hormones. F1 seeds were treated with 0.03% colchicine solution for 6 h and germinated. Cytological observations at peak squaring/flowering stage showed that these plants were hexaploid, having 2n = 6x = 78 chromosomes. The F1 plants showed intermediate expression for leaf size, leaf area, petiole length, bracteole number and size, bracteole area, bracteole dentation, flower size, pedicel size, and petal number and size. Moreover it possessed high fiber strength of 54.4 g/tex, which is 54% greater than that of the check variety, i.e. MNH-786 (G. hirsutum). The F1 population did not show any symptom of CLCuVD in the field, tested by grafting with CLCuVD susceptible rootstock (var. S12). We conclude that it is possible to transfer CLCuVD resistance and high fiber strength from G. stocksii to G. hirsutum.

  3. Detoxification activity and energy cost is attenuated in whiteflies feeding on tomato yellow leaf curl China virus-infected tobacco plants.

    PubMed

    Luan, J-B; Wang, Y-L; Wang, J; Wang, X-W; Liu, S-S

    2013-10-01

    The begomovirus Tomato yellow leaf curl China virus (TYLCCNV) can benefit its vector, the whitefly Bemisia tabaci, through suppressing the defences of their shared host plants. However, the mechanisms of this vector-virus mutualism remain largely unknown on the insect side of the interaction. Here, we compared the transcriptional profiles of female adult whiteflies of B. tabaci Middle East-Asia Minor 1 feeding on TYLCCNV-free and TYLCCNV-infected tobacco plants using the next-generation sequencing technique and quantitative real-time PCR. Interestingly, the genes involved in the oxidative phosphorylation (OXPHOS) pathway and detoxification enzyme were down-regulated in whiteflies feeding on virus-infected plants. Decreased detoxification activity costs less energy, which may reduce OXPHOS activity. Moreover, the genes involved in redox activity were also down-regulated, which may indicate that the reduced OXPHOS activity decreased reactive oxygen species production. Reduced detoxification activity is likely to attenuate energy costs, thereby enhancing the performance of whiteflies on virus-infected plants. These results provide further insight into the mechanisms of the plant-mediated whitefly-virus mutualism. Moreover, our study suggests that investigating the transcriptional profiles on the insect side of the interaction can advance our understanding of the tripartite interactions.

  4. Molecular characterization and infectivity of a Tomato leaf curl New Delhi virus variant associated with newly emerging yellow mosaic disease of eggplant in India

    PubMed Central

    2011-01-01

    Background Begomoviruses have emerged as serious problem for vegetable and fiber crops in the recent past, frequently in tropical and subtropical region of the world. The association of begomovirus with eggplant yellow mosaic disease is hitherto unknown apart from one report from Thailand. A survey in Nagpur, Central India, in 2009-2010 showed severe incidence of eggplant yellow mosaic disease. Here, we have identified and characterized a begomovirus responsible for the newly emerging yellow mosaic disease of eggplant in India. Results The complete DNA-A and DNA-B genomic components of the causative virus were cloned and sequenced. Nucleotide sequence analysis of DNA-A showed that it shared highest 97.6% identity with Tomato leaf curl New Delhi virus-India[India:Udaipur:Okra:2007] and lowest 87.9% identity with Tomato leaf curl New Delhi virus-India[India:NewDelhi:Papaya:2005], while DNA-B showed highest 94.1% identity with ToLCNDV-IN[IN:UD:Ok:07] and lowest 76.2% identity with ToLCNDV-India[India:Lucknow]. Thus, it appears that this begomovirus is a variant of ubiquitous ToLCNDV and hence, we suggest the name ToLCNDV-India[India:Nagpur:Eggplant:2009] for this variant. The pathogenicity of ToLCNDV-IN[IN:Nag:Egg:09] isolate was confirmed by agroinfiltraion and dimeric clones of DNA-A and DNA-B induced characteristic yellow mosaic symptoms in eggplants and leaf curling in tomato plants. Conclusion This is the first report of a ToLCNDV variant moving to a new agriculturally important host, eggplant and causing yellow mosaic disease. This is also a first experimental demonstration of Koch's postulate for a begomovirus associated with eggplant yellow mosaic disease. PMID:21676270

  5. First complete genomic characterization and phylogeny of a new recombinant of tomato yellow leaf curl virus (genus Begomovirus, family Geminiviridae) from Kuwait.

    PubMed

    Al-Ali, Ebtisam H M; Al-Hashash, Hanadi K; Ben-Hejji, Ahmed H; Al-Shayjji, Nabella; Al-Aqeel, Hamed A

    2015-07-01

    While whitefly-transmitted begomoviruses are economically important constraints to tomato production in Kuwait, little is known about genomic features of these viruses from Kuwait. A begomovirus isolated from severely diseased tomatoes, collected over a two-year period in the main tomato-growing areas of Kuwait, was characterized at the molecular level. The complete genomic sequence of the begomovirus was determined, and phlylogeographic studies were conducted to better understand genetic diversity of the virus in the region. Based on genome properties and phylogenetic analysis, the begomovirus was found to be a strain of tomato yellow leaf curl virus (TYLCV). The virus genome was monopartite, as neither DNA B nor satellite DNA molecules were detected. Two isolates characterized in this study shared 97% and 95% nucleotide sequence identity with a previously characterized Kuwaiti isolate, TYLCV-KISR. Among TYLCV isolates with known genome sequences, the Kuwaiti isolates shared highest sequence identity (95%) with TYLCV-Almeria (Spain). Genetic diversity and phylogenetic analysis showed that the three Kuwaiti isolates formed a distinct clade that was separate from those of known TYLCV sequences. One Kuwaiti isolate (KW 1-3) could be a novel variant of TYLCV. Two recombination events were detected in the genome sequence of KW 1-3, which appeared to be a recombinant derived from TYLCV parents from Oman and Kuwait.

  6. Reduction of leaf area and symptom severity as proxies of disease-induced plant mortality: the example of the Cauliflower mosaic virus infecting two Brassicaceae hosts.

    PubMed

    Doumayrou, Juliette; Leblaye, Sophie; Froissart, Rémy; Michalakis, Yannis

    2013-09-01

    Disease induced effects on host survival are important to understand the evolution of parasitic virulence and host resistance/tolerance. Unfortunately, experiments evaluating such effects are in most cases logistically demanding justifying the measurement of survival proxies. For plant hosts commonly used proxies are leaf area and the nature and severity of visual qualitative disease symptoms. In this study we tested whether these traits are indeed correlated to the host mortality rate induced by viral infection. We infected Brassica rapa and Arabidopsis thaliana plants with different natural isolates of Cauliflower mosaic virus (CaMV) and estimated over time the development of symptoms and the relative reduction of leaf area compared to healthy plants and followed plant mortality. We observed that the mortality of infected plants was correlated with the relative reduction of leaf area of both B. rapa and A. thaliana. Measures of mortality were also correlated with the severity of visual qualitative symptoms but the magnitude of the correlations and the time frame at which they were significant depended on the host plant: stronger and earlier correlations were observed on A. thaliana.

  7. Global analysis of the transcriptional response of whitefly to tomato yellow leaf curl China virus reveals the relationship of coevolved adaptations.

    PubMed

    Luan, Jun-Bo; Li, Jun-Min; Varela, Nélia; Wang, Yong-Liang; Li, Fang-Fang; Bao, Yan-Yuan; Zhang, Chuan-Xi; Liu, Shu-Sheng; Wang, Xiao-Wei

    2011-04-01

    The begomoviruses are the largest and most economically important group of plant viruses transmitted exclusively by the whitefly Bemisia tabaci in a circulative, persistent manner. The circulation of the viruses within the insect vectors involves complex interactions between virus and vector components; however, the molecular mechanisms of these interactions remain largely unknown. Here we investigated the transcriptional response of the invasive B. tabaci Middle East-Asia Minor 1 species to Tomato yellow leaf curl China virus (TYLCCNV) using Illumina sequencing technology. Results showed that 1,606 genes involved in 157 biochemical pathways were differentially expressed in the viruliferous whiteflies. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that TYLCCNV can perturb the cell cycle and primary metabolism in the whitefly, which explains the negative effect of this virus on the longevity and fecundity of B. tabaci. Our data also demonstrated that TYLCCNV can activate whitefly immune responses, such as autophagy and antimicrobial peptide production, which might lead to a gradual decrease of viral particles within the body of the viruliferous whitefly. Furthermore, PCR results showed that TYLCCNV can invade the ovary and fat body tissues of the whitefly, and Lysotracker and Western blot analyses revealed that the invasion of TYLCCNV induced autophagy in both the ovary and fat body tissues. Surprisingly, TYLCCNV also suppressed the whitefly immune responses by downregulating the expression of genes involved in Toll-like signaling and mitogen-activated protein kinase (MAPK) pathways. Taken together, these results reveal the relationship of coevolved adaptations between begomoviruses and whiteflies and will provide a road map for future investigations into the complex interactions between plant viruses and their insect vectors.

  8. The complete genomic sequence of pepper yellow leaf curl virus (PYLCV) and its implications for our understanding of evolution dynamics in the genus polerovirus.

    PubMed

    Dombrovsky, Aviv; Glanz, Eyal; Lachman, Oded; Sela, Noa; Doron-Faigenboim, Adi; Antignus, Yehezkel

    2013-01-01

    We determined the complete sequence and organization of the genome of a putative member of the genus Polerovirus tentatively named Pepper yellow leaf curl virus (PYLCV). PYLCV has a wider host range than Tobacco vein-distorting virus (TVDV) and has a close serological relationship with Cucurbit aphid-borne yellows virus (CABYV) (both poleroviruses). The extracted viral RNA was subjected to SOLiD next-generation sequence analysis and used as a template for reverse transcription synthesis, which was followed by PCR amplification. The ssRNA genome of PYLCV includes 6,028 nucleotides encoding six open reading frames (ORFs), which is typical of the genus Polerovirus. Comparisons of the deduced amino acid sequences of the PYLCV ORFs 2-4 and ORF5, indicate that there are high levels of similarity between these sequences to ORFs 2-4 of TVDV (84-93%) and to ORF5 of CABYV (87%). Both PYLCV and Pepper vein yellowing virus (PeVYV) contain sequences that point to a common ancestral polerovirus. The recombination breakpoint which is located at CABYV ORF3, which encodes the viral coat protein (CP), may explain the CABYV-like sequences found in the genomes of the pepper infecting viruses PYLCV and PeVYV. Two additional regions unique to PYLCV (PY1 and PY2) were identified between nucleotides 4,962 and 5,061 (ORF 5) and between positions 5,866 and 6,028 in the 3' NCR. Sequence analysis of the pepper-infecting PeVYV revealed three unique regions (Pe1-Pe3) with no similarity to other members of the genus Polerovirus. Genomic analyses of PYLCV and PeVYV suggest that the speciation of these viruses occurred through putative recombination event(s) between poleroviruses co-infecting a common host(s), resulting in the emergence of PYLCV, a novel pathogen with a wider host range.

  9. Analysis of the Mild strain of tomato yellow leaf curl virus, which overcomes Ty-2 gene-mediated resistance in tomato line H24.

    PubMed

    Ohnishi, Jun; Yamaguchi, Hirotaka; Saito, Atsushi

    2016-08-01

    In tomato line H24, an isolate of the Mild (Mld) strain of tomato yellow leaf curl virus (TYLCV-Mld [JR:Kis]) overcomes Ty-2 gene-mediated resistance and causes typical symptoms of tomato yellow leaf curl disease (TYLCD). No systemic infection with visible symptoms or accumulation of viral DNA in the upper leaves was observed in H24 challenged with another isolate, TYLCV-IL (TYLCV-IL [JR:Osaka]), confirming that H24 is resistant to the IL strain. To elucidate the genomic regions that cause the breakdown of the Ty-2 gene-mediated resistance, we constructed a series of chimeras by swapping genes between the two strains. A chimeric virus that had the overlapping C4/Rep region of the Mld strain in the context of the IL strain genome, caused severe TYLCD in H24 plants, suggesting that the overlapping C4/Rep region of the Mld strain is associated with the ability of this strain to overcome Ty-2 gene-mediated resistance.

  10. Water Balance, Hormone Homeostasis, and Sugar Signaling Are All Involved in Tomato Resistance to Tomato Yellow Leaf Curl Virus1[C][W][OPEN

    PubMed Central

    Sade, Dagan; Sade, Nir; Shriki, Oz; Lerner, Stephen; Gebremedhin, Alem; Karavani, Asaf; Brotman, Yariv; Osorio, Sonia; Fernie, Alisdair R.; Willmitzer, Lothar; Czosnek, Henryk; Moshelion, Menachem

    2014-01-01

    Vacuolar water movement is largely controlled by membrane channels called tonoplast-intrinsic aquaporins (TIP-AQPs). Some TIP-AQP genes, such as TIP2;2 and TIP1;1, are up-regulated upon exposure to biotic stress. Moreover, TIP1;1 transcript levels are higher in leaves of a tomato (Solanum lycopersicum) line resistant to Tomato yellow leaf curl virus (TYLCV) than in those of a susceptible line with a similar genetic background. Virus-induced silencing of TIP1;1 in the tomato resistant line and the use of an Arabidopsis (Arabidopsis thaliana) tip1;1 null mutant showed that resistance to TYLCV is severely compromised in the absence of TIP1:1. Constitutive expression of tomato TIP2;2 in transgenic TYLCV-susceptible tomato and Arabidopsis plants was correlated with increased TYLCV resistance, increased transpiration, decreased abscisic acid levels, and increased salicylic acid levels at the early stages of infection. We propose that TIP-AQPs affect the induction of leaf abscisic acid, which leads to increased levels of transpiration and gas exchange, as well as better salicylic acid signaling. PMID:24989233

  11. CONTROL FOR ROLLING MILL

    DOEpatents

    Shuck, A.B.; Shaw, W.C.

    1961-06-20

    A plutonium-rolling apparatus is patented that has two sets of feed rolls, shaping rolls between the feed rolls, and grippers beyond the feed rolls, which ready a workpiece for a new pass through the shaping rolls by angularly shifting the workpiece about its axis or transversely moving it on a line parallel to the axes of the shaping rolls. Actuation of each gripper for gripping or releasing the workpiece is produced by the relative positions assumed by the feed rolls adjacent to the gripper as the workpiece enters or leaves the feed rolls.

  12. Rolling Uphill

    NASA Astrophysics Data System (ADS)

    Cross, Rod

    2017-04-01

    In a recent letter to this journal, Mungan noted that translational energy can be converted into gravitational potential energy when an object is projected vertically, but rotational energy is not usually converted in this manner. As an exception, he gave an example where "a ball initially rolling without slipping will travel higher up a rough ramp than it will up a frictionless ramp." However, such a result is unlikely to be observed in practice. A better example would be a ball spinning rapidly forwards as it slides up the ramp, since the friction force on the ball then acts in a direction up the ramp.

  13. Dynamics of defense-related components in two contrasting genotypes of tomato upon infection with Tomato Leaf Curl New Delhi Virus.

    PubMed

    Sahu, Pranav Pankaj; Rai, Neeraj Kumar; Puranik, Swati; Roy, Anirban; Khan, Moinuddin; Prasad, Manoj

    2012-10-01

    Tomato leaf curl virus (ToLCV) disease is a serious threat for tomato cultivation in the tropics and subtropics. Despite serious efforts no immune commercial varieties or F(1) hybrids are available till date. In this study, the interaction between Solanum lycopersicum and ToLCV was characterized on molecular and biochemical basis. RNA silencing mediated by short interfering RNA (siRNA) and reactive oxygen species (ROS) has been proposed as central components of plant adaptation to several stresses. A comparative RNA interference study between two contrasting tomato genotypes, LA1777 (tolerant) and 15SBSB (susceptible) infected with Tomato Leaf Curl New Delhi Virus (ToLCNDV) revealed relatively higher accumulation of siRNA in the leaves of tolerant genotype. In LA1777, ToLCNDV produced chlorotic as well as necrotic areas at the inoculation sites 5-10 days post-inoculation. Caspase-9- and caspase-3-like activities were significantly increased in response to ToLCNDV infection in LA1777 at inoculated region. Activities of antioxidant enzymes involved in the detoxification of ROS were examined in both systemic and localized area of infection, and their expression level was further validated through quantitative real-time PCR of the corresponding transcripts. Expression patterns of three genes encoding pathogenesis-related proteins showed higher accumulation in tolerant genotype. Tolerance against the ToLCNDV in LA1777 can be attributed to the higher siRNA accumulation, localized cell death, altered levels of antioxidant enzymes and activation of pathogenesis-related genes at different durations of virus infection. Based on these direct and indirect evidences, we have proposed a putative mechanism for ToLCNDV tolerance in the tolerant genotype.

  14. Molecular characterization of Citrus tatter leaf virus historically associated with Meyer lemon trees: complete genome sequence and development of biologically active in vitro transcripts.

    PubMed

    Tatineni, Satyanarayana; Afunian, Mohammad R; Hilf, Mark E; Gowda, Siddarame; Dawson, William O; Garnsey, Stephen M

    2009-04-01

    Citrus tatter leaf virus isolated from Meyer lemon trees (CTLV-ML) from California and Florida induces bud union incompatibility of citrus trees grafted on the widely used trifoliate and trifoliate hybrid rootstocks. The complete genome sequence of CTLV-ML was determined to be 6,495 nucleotides (nts), with two overlapping open reading frames (ORFs) and a poly (A) tail at the 3' end. The genome organization is similar to other capilloviruses, with ORF1 (nts 37 to 6,354) encoding a putative 242-kDa polyprotein which contains replication-associated domains plus a coat protein (CP), and ORF2 (nts 4,788 to 5,750), which is located within ORF1 in a different reading frame and encodes a putative movement protein. Although the proteins encoded by CTLV-ML possesses 84 to 96% amino acid sequence identity with strains of Apple stem grooving virus (ASGV), we observed two strikingly different regions in ORF1: variable region I (amino acids 532 to 570) and variable region II (amino acids 1,583 to 1,868), with only 15 to 18 and 56 to 62% identities, respectively, with the corresponding regions of ASGV strains. Conditions for a herbaceous systemic assay host were optimized in which the wild-type virus induced systemic infection in Phaseolus vulgaris cv. Light Red Kidney (LRK) bean plants at 19 or 22 degrees C but not at higher temperatures. In vitro transcripts generated from full-length cDNA clones induced systemic symptoms on LRK bean plants similar to that of the wild-type virus. Replication of the recombinant virus was confirmed by hybridization of a 5' positive-stranded RNA-specific probe to a genome-sized RNA and by reverse-transcription polymerase chain reaction.

  15. Mapping quantitative trait loci of resistance to Tomato spotted wilt virus and leaf spots in a recombinant inbred line population of peanut (Arachis hypogae L.) from SunOleic 97R and NC94022

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Peanut is vulnerable to a range of diseases, such as Tomato spotted wilt virus (TSWV) and leaf spots. The most sustainable and economical solution for managing peanut diseases is development of resistance cultivars. The new breeding line NC94022, high resistance to TSWV and moderate resistance to le...

  16. MU06-857, a Green Leaf Lettuce Breeding Line with Resistance to Leafminer and Lettuce Mosaic Virus.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Agricultural Research Service, United States Department of Agriculture announces the release of a breeding line of green leaf lettuce (Lactuca sativa L.) with resistance to leafminers (Liriomyza langei Frick) and lettuce mosaic. The line MU06-857 is similar to cultivar ‘Lolla Rossa’ (‘Lollo Ros...

  17. Precocious flowering of juvenile citrus induced by a viral vector based on Citrus leaf blotch virus: a new tool for genetics and breeding.

    PubMed

    Velázquez, Karelia; Agüero, Jesús; Vives, María C; Aleza, Pablo; Pina, José A; Moreno, Pedro; Navarro, Luis; Guerri, José

    2016-10-01

    The long juvenile period of citrus trees (often more than 6 years) has hindered genetic improvement by traditional breeding methods and genetic studies. In this work, we have developed a biotechnology tool to promote transition from the vegetative to the reproductive phase in juvenile citrus plants by expression of the Arabidopsis thaliana or citrus FLOWERING LOCUS T (FT) genes using a Citrus leaf blotch virus-based vector (clbvINpr-AtFT and clbvINpr-CiFT, respectively). Citrus plants of different genotypes graft inoculated with either of these vectors started flowering within 4-6 months, with no alteration of the plant architecture, leaf, flower or fruit morphology in comparison with noninoculated adult plants. The vector did not integrate in or recombine with the plant genome nor was it pollen or vector transmissible, albeit seed transmission at low rate was detected. The clbvINpr-AtFT is very stable, and flowering was observed over a period of at least 5 years. Precocious flowering of juvenile citrus plants after vector infection provides a helpful and safe tool to dramatically speed up genetic studies and breeding programmes.

  18. SlMAPK3 enhances tolerance to tomato yellow leaf curl virus (TYLCV) by regulating salicylic acid and jasmonic acid signaling in tomato (Solanum lycopersicum)

    PubMed Central

    Li, Yunzhou; Qin, Lei; Zhao, Jingjing; Muhammad, Tayeb; Cao, Hehe; Li, Hailiang; Zhang, Yan; Liang, Yan

    2017-01-01

    Several recent studies have reported on the role of mitogen-activated protein kinase (MAPK3) in plant immune responses. However, little is known about how MAPK3 functions in tomato (Solanum lycopersicum L.) infected with tomato yellow leaf curl virus (TYLCV). There is also uncertainty about the connection between plant MAPK3 and the salicylic acid (SA) and jasmonic acid (JA) defense-signaling pathways. The results of this study indicated that SlMAPK3 participates in the antiviral response against TYLCV. Tomato seedlings were inoculated with TYLCV to investigate the possible roles of SlMAPK1, SlMAPK2, and SlMAPK3 against this virus. Inoculation with TYLCV strongly induced the expression and the activity of all three genes. Silencing of SlMAPK1, SlMAPK2, and SlMAPK3 reduced tolerance to TYLCV, increased leaf H2O2 concentrations, and attenuated expression of defense-related genes after TYLCV infection, especially in SlMAPK3-silenced plants. Exogenous SA and methyl jasmonic acid (MeJA) both significantly induced SlMAPK3 expression in tomato leaves. Over-expression of SlMAPK3 increased the transcript levels of SA/JA-mediated defense-related genes (PR1, PR1b/SlLapA, SlPI-I, and SlPI-II) and enhanced tolerance to TYLCV. After TYLCV inoculation, the leaves of SlMAPK3 over-expressed plants compared with wild type plants showed less H2O2 accumulation and greater superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) activity. Overall, the results suggested that SlMAPK3 participates in the antiviral response of tomato to TYLCV, and that this process may be through either the SA or JA defense-signaling pathways. PMID:28222174

  19. Amino Acids in the Capsid Protein of Tomato Yellow Leaf Curl Virus That Are Crucial for Systemic Infection, Particle Formation, and Insect Transmission

    PubMed Central

    Noris, E.; Vaira, A. M.; Caciagli, P.; Masenga, V.; Gronenborn, B.; Accotto, G. P.

    1998-01-01

    A functional capsid protein (CP) is essential for host plant infection and insect transmission in monopartite geminiviruses. We studied two defective genomic DNAs of tomato yellow leaf curl virus (TYLCV), Sic and SicRcv. Sic, cloned from a field-infected tomato, was not infectious, whereas SicRcv, which spontaneously originated from Sic, was infectious but not whitefly transmissible. A single amino acid change in the CP was found to be responsible for restoring infectivity. When the amino acid sequences of the CPs of Sic and SicRcv were compared with that of a closely related wild-type virus (TYLCV-Sar), differences were found in the following positions: 129 (P in Sic and SicRcv, Q in Sar), 134 (Q in Sic and Sar, H in SicRcv) and 152 (E in Sic and SicRcv, D in Sar). We constructed TYLCV-Sar variants containing the eight possible amino acid combinations in those three positions and tested them for infectivity and transmissibility. QQD, QQE, QHD, and QHE had a wild-type phenotype, whereas PHD and PHE were infectious but nontransmissible. PQD and PQE mutants were not infectious; however, they replicated and accumulated CP, but not virions, in Nicotiana benthamiana leaf discs. The Q129P replacement is a nonconservative change, which may drastically alter the secondary structure of the CP and affect its ability to form the capsid. The additional Q134H change, however, appeared to compensate for the structural modification. Sequence comparisons among whitefly-transmitted geminiviruses in terms of the CP region studied showed that combinations other than QQD are present in several cases, but never with a P129. PMID:9811744

  20. Silk gland gene expression during larval-pupal transitionin the cotton leaf roller Sylepta derogate (Lepidoptera: pyralidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The cotton leaf roller, Sylepta derogata, is a silk-producing insect pest. While young larvae feed on the underside of leaves, the older ones roll cotton leaves and feed on the leaf edges, which defoliates cotton plants. The larvae produce silk to stabilize the rolled leaf and to balloon from used t...

  1. Rolling-Element Bearings

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.; Anderson, W. J.

    1983-01-01

    Rolling element bearings are a precision, yet simple, machine element of great utility. A brief history of rolling element bearings is reviewed and the type of rolling element bearings, their geometry and kinematics, as well as the materials they are made from and the manufacturing processes they involve are described. Unloaded and unlubricated rolling element bearings, loaded but unlubricated rolling element bearings and loaded and lubricated rolling element bearings are considered. The recognition and understanding of elastohydrodynamic lubrication covered, represents one of the major development in rolling element bearings.

  2. Kinetics of interaction of Cotton Leaf Curl Kokhran Virus-Dabawali (CLCuKV-Dab) coat protein and its mutants with ssDNA

    SciTech Connect

    Priyadarshini, C.G. Poornima; Savithri, H.S.

    2009-04-10

    Gemini viral assembly and transport of viral DNA into nucleus for replication, essentially involve DNA-coat protein interactions. The kinetics of interaction of Cotton Leaf Curl Kokhran Virus-Dabawali recombinant coat protein (rCP) with DNA was studied by electrophoretic mobility shift assay (EMSA) and surface plasmon resonance (SPR). The rCP interacted with ssDNA with a K{sub A}, of 2.6 +- 0.29 x 10{sup 8} M{sup -1} in a sequence non-specific manner. The CP has a conserved C2H2 type zinc finger motif composed of residues C68, C72, H81 and H85. Mutation of these residues to alanine resulted in reduced binding to DNA probes. The H85A mutant rCP showed the least binding with approximately 756 fold loss in the association rate and a three order magnitude decrease in the binding affinity as compared to rCP. The CP-DNA interactions via the zinc finger motif could play a crucial role in virus assembly and in nuclear transport.

  3. The minimal sequence essential for replication and movement of Cotton leaf curl Multan betasatellite DNA by a helper virus in plant cells.

    PubMed

    Eini, Omid; Behjatnia, S A Akbar

    2016-10-01

    Betasatellites are single-stranded circular DNAs associated with a number of monopartite begomoviruses. Betasatellites rely on the helper begomoviruses for replication and movement in plant tissues and plant-to-plant transmission by vectors. Their genomes are approximately half the size of the helper viruses and consist of three main regions including the βC1 gene, an adenine-rich (A-rich) region, and the satellite conserved region (SCR). In this study, we investigated the minimal sequences required for Cotton leaf curl Multan betasatellite (CLCuMB) replication and movement. Mutational analysis of CLCuMB DNA genome indicated that βC1 gene and A-rich region were not required for trans-replication and movement of CLCuMB in host plants by a helper virus. Deletion of βC1 gene and a fragment (135 nt in length) upstream of this gene impaired CLCuMB replication. However, CLCuMB mutant with deletion of βC1 gene and a further 163 nucleotides replicated at a lower level as compared to the wild-type betasatellite. This suggests that there are essential elements in the fragment upstream of βC1 gene, which are required for the replication of CLCuMB rather than the size limitation of CLCuMB DNA.

  4. The Whitefly Bemisia tabaci Knottin-1 Gene Is Implicated in Regulating the Quantity of Tomato Yellow Leaf Curl Virus Ingested and Transmitted by the Insect

    PubMed Central

    Hariton Shalev, Aliza; Sobol, Iris; Ghanim, Murad; Liu, Shu-Sheng; Czosnek, Henryk

    2016-01-01

    The whitefly Bemisia tabaci is a major pest to agricultural crops. It transmits begomoviruses, such as Tomato yellow leaf curl virus (TYLCV), in a circular, persistent fashion. Transcriptome analyses revealed that B. tabaci knottin genes were responsive to various stresses. Upon ingestion of tomato begomoviruses, two of the four knottin genes were upregulated, knot-1 (with the highest expression) and knot-3. In this study, we examined the involvement of B. tabaci knottin genes in relation to TYLCV circulative transmission. Knottins were silenced by feeding whiteflies with knottin dsRNA via detached tomato leaves. Large amounts of knot-1 transcripts were present in the abdomen of whiteflies, an obligatory transit site of begomoviruses in their circulative transmission pathway; knot-1 silencing significantly depleted the abdomen from knot-1 transcripts. Knot-1 silencing led to an increase in the amounts of TYLCV ingested by the insects and transmitted to tomato test plants by several orders of magnitude. This effect was not observed following knot-3 silencing. Hence, knot-1 plays a role in restricting the quantity of virions an insect may acquire and transmit. We suggest that knot-1 protects B. tabaci against deleterious effects caused by TYLCV by limiting the amount of virus associated with the whitefly vector. PMID:27455309

  5. Rapid Construction of Stable Infectious Full-Length cDNA Clone of Papaya Leaf Distortion Mosaic Virus Using In-Fusion Cloning

    PubMed Central

    Tuo, Decai; Shen, Wentao; Yan, Pu; Li, Xiaoying; Zhou, Peng

    2015-01-01

    Papaya leaf distortion mosaic virus (PLDMV) is becoming a threat to papaya and transgenic papaya resistant to the related pathogen, papaya ringspot virus (PRSV). The generation of infectious viral clones is an essential step for reverse-genetics studies of viral gene function and cross-protection. In this study, a sequence- and ligation-independent cloning system, the In-Fusion® Cloning Kit (Clontech, Mountain View, CA, USA), was used to construct intron-less or intron-containing full-length cDNA clones of the isolate PLDMV-DF, with the simultaneous scarless assembly of multiple viral and intron fragments into a plasmid vector in a single reaction. The intron-containing full-length cDNA clone of PLDMV-DF was stably propagated in Escherichia coli. In vitro intron-containing transcripts were processed and spliced into biologically active intron-less transcripts following mechanical inoculation and then initiated systemic infections in Carica papaya L. seedlings, which developed similar symptoms to those caused by the wild-type virus. However, no infectivity was detected when the plants were inoculated with RNA transcripts from the intron-less construct because the instability of the viral cDNA clone in bacterial cells caused a non-sense or deletion mutation of the genomic sequence of PLDMV-DF. To our knowledge, this is the first report of the construction of an infectious full-length cDNA clone of PLDMV and the splicing of intron-containing transcripts following mechanical inoculation. In-Fusion cloning shortens the construction time from months to days. Therefore, it is a faster, more flexible, and more efficient method than the traditional multistep restriction enzyme-mediated subcloning procedure. PMID:26633465

  6. Rapid Construction of Stable Infectious Full-Length cDNA Clone of Papaya Leaf Distortion Mosaic Virus Using In-Fusion Cloning.

    PubMed

    Tuo, Decai; Shen, Wentao; Yan, Pu; Li, Xiaoying; Zhou, Peng

    2015-12-01

    Papaya leaf distortion mosaic virus (PLDMV) is becoming a threat to papaya and transgenic papaya resistant to the related pathogen, papaya ringspot virus (PRSV). The generation of infectious viral clones is an essential step for reverse-genetics studies of viral gene function and cross-protection. In this study, a sequence- and ligation-independent cloning system, the In-Fusion(®) Cloning Kit (Clontech, Mountain View, CA, USA), was used to construct intron-less or intron-containing full-length cDNA clones of the isolate PLDMV-DF, with the simultaneous scarless assembly of multiple viral and intron fragments into a plasmid vector in a single reaction. The intron-containing full-length cDNA clone of PLDMV-DF was stably propagated in Escherichia coli. In vitro intron-containing transcripts were processed and spliced into biologically active intron-less transcripts following mechanical inoculation and then initiated systemic infections in Carica papaya L. seedlings, which developed similar symptoms to those caused by the wild-type virus. However, no infectivity was detected when the plants were inoculated with RNA transcripts from the intron-less construct because the instability of the viral cDNA clone in bacterial cells caused a non-sense or deletion mutation of the genomic sequence of PLDMV-DF. To our knowledge, this is the first report of the construction of an infectious full-length cDNA clone of PLDMV and the splicing of intron-containing transcripts following mechanical inoculation. In-Fusion cloning shortens the construction time from months to days. Therefore, it is a faster, more flexible, and more efficient method than the traditional multistep restriction enzyme-mediated subcloning procedure.

  7. Effect of a single amino acid substitution in the NLS domain of Tomato yellow leaf curl virus-Israel (TYLCV-IL) capsid protein (CP) on its activity and on the virus life cycle.

    PubMed

    Yaakov, Noga; Levy, Yael; Belausov, Eduard; Gaba, Victor; Lapidot, Moshe; Gafni, Yedidya

    2011-06-01

    The capsid protein (CP) of Tomato yellow leaf curl virus-Israel (TYLCV-IL), encoded by the v1 gene, is the only known component of the viral capsid. Three point mutations introduced into the conserved NLS region of the CP were investigated. One mutant, in which the Arg at position 19 was converted to Leu, had the most significant effect on the CP-CP homotypic interaction as well as on CP's interaction with its nuclear receptor karyopherin α1 and with the protein GroEL. The latter has been suggested to protect the virions in the insect vector hemolymph. These effects were first observed by yeast two-hybrid assay and then confirmed in tobacco protoplasts by measuring fluorescence resonance energy transfer (FRET) between YFP- and CFP-tagged proteins. Most importantly, when the point mutation converting Arg 19 to Leu was introduced into the full-length TYLCV genome, it disrupted its ability to cause symptoms.

  8. Comparative transcriptome analysis in Bemisia tabaci in response to tomato yellow leaf curl virus and development of ribonucleic acid interference to manage whitefly-transmitted viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The whitefly, Bemisia tabaci transmits over 300 plant viruses, with the majority of them belonging to the Begomovirus genus. Begomoviruses are obligately transmitted to a wide range of agriculture crops, resulting in the loss of billions of dollars annually, while jeopardizing food security worldwid...

  9. Transcriptome analysis of Bemisia tabaci during tomato yellow leaf curl virus acquisition and ribonucleic acid interference to manage whitefly-transmitted viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over 300 viruses are transmitted by the whitefly, Bemisia tabaci, with 90% of them belonging to the genus, Begomovirus. Begomoviruses are obligately transmitted by whiteflies to a wide range of agriculture crops, resulting in billions of dollars lost annually, while jeopardizing food security worldw...

  10. Yellowing disease in zucchini squash produced by mixed infections of Cucurbit yellow stunting disorder virus and Cucumber vein yellowing virus.

    PubMed

    Gil-Salas, Francisco M; Peters, Jeff; Boonham, Neil; Cuadrado, Isabel M; Janssen, Dirk

    2011-11-01

    Zucchini squash is host to Cucurbit yellow stunting disorder virus (CYSDV), a member of the genus Crinivirus, and Cucumber vein yellowing virus (CVYV), a member of the genus Ipomovirus, both transmitted by the whitefly Bemisia tabaci. Field observations suggest the appearance of new symptoms observed on leaves of zucchini squash crops when both viruses were present. When infected during controlled experiments with CYSDV only, zucchini plants showed no obvious symptoms and the virus titer decreased between 15 and 45 days postinoculation (dpi), after which it was no longer detected. CVYV caused inconspicuous symptoms restricted to vein clearing on some of the apical leaves and the virus accumulated progressively between 15 and 60 dpi. Similar accumulations of virus followed single inoculations with the potyvirus Zucchini yellow mosaic virus (ZYMV) and plants showed severe stunting, leaf deformation, and mosaic yellowing. However, in mixed infections with CYSDV and CVYV, intermediate leaves showed chlorotic mottling which evolved later to rolling, brittleness, and complete yellowing of the leaf lamina, with exception of the veins. No consistent alteration of CVYV accumulation was detected but the amounts of CYSDV increased ≈100-fold and remained detectable at 60 dpi. Such synergistic effects on the titer of the crinivirus and symptom expression were not observed when co-infected with ZYMV.

  11. Internal roll compression system

    DOEpatents

    Anderson, Graydon E.

    1985-01-01

    This invention is a machine for squeezing water out of peat or other material of low tensile strength; the machine including an inner roll eccentrically positioned inside a tubular outer roll, so as to form a gradually increasing pinch area at one point therebetween, so that, as the rolls rotate, the material is placed between the rolls, and gets wrung out when passing through the pinch area.

  12. Eugenol confers resistance to Tomato yellow leaf curl virus (TYLCV) by regulating the expression of SlPer1 in tomato plants.

    PubMed

    Sun, Wei-Jie; Lv, Wen-Jing; Li, Li-Na; Yin, Gan; Hang, Xiaofang; Xue, Yanfeng; Chen, Jian; Shi, Zhiqi

    2016-05-25

    Tomato yellow leaf curl virus (TYLCV) is one of the most devastating plant diseases, and poses a significant agricultural concern because of the lack of an efficient control method. Eugenol is a plant-derived natural compound that has been widely used as a food additive and in medicine. In the present study, we demonstrated the potential of eugenol to enhance the resistance of tomato plants to TYLCV. The anti-TYLCV efficiency of eugenol was significantly higher than that of moroxydine hydrochloride (MH), a widely used commercial antiviral agent. Eugenol application stimulated the production of endogenous nitric oxide (NO) and salicylic acid (SA) in tomato plants. The full-length cDNA of SlPer1, which has been suggested to be a host R gene specific to TYLCV, was isolated from tomato plants. A sequence analysis suggested that SlPer1 might be a nucleobase-ascorbate transporter (NAT) belonging to the permease family. The transcript levels of SlPer1 increased markedly in response to treatment with eugenol or TYLCV inoculation. The results of this study also showed that SlPer1 expression was strongly induced by SA, MeJA (jasmonic acid methyl ester), and NO. Thus, we propose that the increased transcription of SlPer1 contributed to the high anti-TYLCV efficiency of eugenol, which might involve in the generation of endogenous SA and NO. Such findings provide the basis for the development of eugenol as an environmental-friendly agricultural antiviral agent.

  13. Strategies to facilitate the development of uncloned or cloned infectious full-length viral cDNAs: Apple chlorotic leaf spot virus as a case study

    PubMed Central

    2011-01-01

    Background Approaches to simplify and streamline the construction of full-length infectious cDNA clones (FL-cDNAs) are needed. Among desirable improvements are the ability to use total nucleic acids (TNA) extracts from infected hosts (to bypass viral purification limitations) for the direct one-step amplification of large FL-cDNAs, the possibility to inoculate plants with uncloned FL-cDNAs and the simplified cloning of these large molecules. Results Using the 7.55 kb genome of Apple chlorotic leaf spot trichovirus (ACLSV) approaches allowing the rapid generation from TNA extracts of FL-cDNAs under the control of the T7 promoter and the successful inoculation of plants using in vitro transcripts obtained from these uncloned amplification products have been developed. We also show that the yeast homologous recombination system permits efficient cloning of FL-cDNAs and the simultaneous one-step tailoring of a ternary Yeast-Escherichia coli-Agrobacterium tumefaciens shuttle vector allowing efficient inoculation of both herbaceous and woody host plants by agroinfiltration. Conclusions The fast and efficient strategies described here should have broad applications, in particular for the study of "difficult" plant viruses, such as those infecting woody hosts, and potentially for other, non plant-infecting viral agents. PMID:22040379

  14. Complete nucleotide sequences of the genomes of two isolates of apple chlorotic leaf spot virus from peach (Prunus persica) in China.

    PubMed

    Niu, Feiqing; Pan, Song; Wu, Zujian; Jiang, Dongmei; Li, Shifang

    2012-04-01

    The complete nucleotide sequences of two isolates of apple chlorotic leaf spot virus (Z1 and Z3) collected from peach in Henan Province, China, were determined. The genomes of both Z1 and Z3 were found to contain three open reading frames (ORFs). Sequence analysis showed that genomic sequences of Z1 and Z3 isolates shared 67.4%-82.9% and 67.2%-82.6% identity, respectively, with the other eight isolates of ACLSV that have been reported previously. Based on the putative amino acid sequences of the products of the three ORFs, Z1 and Z3 isolates showed the greatest identity to isolate PBM1 (GenBank accession number AJ243438) from plum and the least identity with isolate Ta Tao5 (GenBank Accession Number: EU223295) from peach. Considering the low level of sequence identity between Z1/Z3 isolate and Ta Tao5 isolate, two types of ACLSV may exist in peach.

  15. The Cucumber leaf spot virus p25 auxiliary replicase protein binds and modifies the endoplasmic reticulum via N-terminal transmembrane domains

    SciTech Connect

    Ghoshal, Kankana; Theilmann, Jane; Reade, Ron; Sanfacon, Helene; Rochon, D’Ann

    2014-11-15

    Cucumber leaf spot virus (CLSV) is a member of the Aureusvirus genus, family Tombusviridae. The auxiliary replicase of Tombusvirids has been found to localize to endoplasmic reticulum (ER), peroxisomes or mitochondria; however, localization of the auxiliary replicase of aureusviruses has not been determined. We have found that the auxiliary replicase of CLSV (p25) fused to GFP colocalizes with ER and that three predicted transmembrane domains (TMDs) at the N-terminus of p25 are sufficient for targeting, although the second and third TMDs play the most prominent roles. Confocal analysis of CLSV infected 16C plants shows that the ER becomes modified including the formation of punctae at connections between ER tubules and in association with the nucleus. Ultrastructural analysis shows that the cytoplasm contains numerous vesicles which are also found between the perinuclear ER and nuclear membrane. It is proposed that these vesicles correspond to modified ER used as sites for CLSV replication. - Highlights: • The CLSV p25 auxiliary replicase targets the endoplasmic reticulum (ER). • Targeting of CLSV p25 is associated with ER restructuring. • Restructuring of the ER occurs during CLSV infection. • CLSV p25 contains 3 predicted transmembrane domains 2 of which are required for ER targeting. • Vesicles derived from the ER may be sites of CLSV replication.

  16. Transferring cucumber mosaic virus-white leaf strain coat protein gene into Cucumis melo L. and evaluating transgenic plants for protection against infections

    SciTech Connect

    Gonsalves, C.; Xue, B.; Yepes, M.; Fuchs, M.; Ling, K.; Namba, S. . Dept. of Plant Pathology)

    1994-03-01

    A single regeneration procedure using cotyledon examples effectively regenerated five commercially grown muskmelon cultivars. This regeneration scheme was used to facilitate gene transfers using either Agrobacterium tumefaciens or microprojectile bombardment methods. In both cases, the transferred genes were from the T-DNA region of the binary vector plasmid pGA482GG/cp cucumber mosaic virus-white leaf strain (CMV-WL), which contains genes that encode neomycin phosphotransferase II (NPT II), [beta]-glucuronidase (GUS), and the CMV-WL coat protein (CP). Explants treated with pGA482GG/cpCMV-WL regenerated shoots on Murashige and Skoog medium containing 4.4 [mu]m 6-benzylaminopurine (BA), kanamycin (Km) at 150 mg[center dot]liter[sup [minus]1] and carbenicillin (Cb) at 500 mg[center dot]liter[sup [minus]1]. The authors' comparison of A. tumefaciens- and microprojectile-mediated gene transfer procedures shows that both methods effectively produce nearly the same percentage of transgenic plants. R[sub 0] plants were first tested for GUS or NPT II expression, then the polymerase chain reaction (PCR) and other tests were used to verify the transfer of the NPT II, GUS, and CMV-WL CP genes.

  17. Generation and characterization of a scFv against recombinant coat protein of the geminivirus tomato leaf curl New Delhi virus.

    PubMed

    Zakri, Adel M; Ziegler, Angelika; Torrance, Lesley; Fischer, Rainer; Commandeur, Ulrich

    2010-03-01

    We report the establishment of a hybridoma cell line secreting the monoclonal antibody (mAb) HAV, which recognizes the coat (AV1) protein of tomato leaf curl New Delhi virus (ToLCNDV), a begomovirus. The cell line was obtained following immunization of mice with purified recombinant AV1 fused to glutathione S-transferase (GST). A single-chain variable fragment (scFv-SAV) was assembled from hybridoma cDNA, but sequence analysis revealed a single nucleotide deletion causing a frame shift that resulted in a 21-residue N-terminal truncation. The missing nucleotide was restored by in vitro site-directed mutagenesis to create scFv-RWAV. The binding properties of mAb HAV and the corresponding scFvs were characterized by western blot, ELISA and surface plasmon resonance spectroscopy. MAb HAV bound to AV1 with nanomolar affinity but reacted neither with the N-terminal region of the protein nor with the GST fusion partner. This suggested that the antibody recognized a linear epitope in a region of the coat protein that is conserved among begomoviruses. Both scFvs retained the antigen specificity of mAb HAV, although the dissociation rate constant of scFv-RWAV was tenfold greater than that of scFv-SAV, showing the importance of restoring the 21 N-terminal amino acids.

  18. Effectiveness of Cyantraniliprole for Managing Bemisia tabaci (Hemiptera: Aleyrodidae) and Interfering with Transmission of Tomato Yellow Leaf Curl Virus on Tomato.

    PubMed

    Caballero, Rafael; Schuster, David J; Peres, Natalia A; Mangandi, Jozer; Hasing, Tomas; Trexler, Fred; Kalb, Steve; Portillo, Héctor E; Marçon, Paula C; Annan, I B

    2015-06-01

    Cyantraniliprole is the second xylem-systemic active ingredient in the new anthranilic diamide class. Greenhouse (2006), growth chamber (2007), and field studies (2009-2010) were conducted to determine the efficacy of cyantraniliprole for managing Bemisia tabaci (Gennadius) biotype B and in interfering with transmission of tomato yellow leaf curl virus (TYLCV) by this whitefly. Cyantraniliprole applied as soil treatments (200 SC) or foliar sprays (100 OD) provided excellent adult whitefly control, TYLCV suppression, and reduced oviposition and nymph survival, comparable to current standards. The positive results observed in these greenhouse experiments with a high level of insect pressure (10× the field threshold of one adult per plant) and disease pressure (five adults per plant, with a high level of confidence that TYLCV virulent adults were used), indicate a great potential for cyantraniliprole to be used in a whitefly management program. Field evaluations of soil drench treatments confirmed the suppression of TYLCV transmission demonstrated in the greenhouse studies. Field studies in 2009 and 2010 showed that cyantraniliprole (200 SC) provided TYLCV suppression for 2 wk after a drench application, when using a susceptible (2009) or imidacloprid-tolerant (2010) whitefly population. Cyantraniliprole was demonstrated to be a promising tool for management of TYLCV in tomato production, which is very difficult and expensive, and which has limited options. The integration of cyantraniliprole into a resistance management program will help to ensure the continued sustainability of this and current insecticides used for the management of insect vectors, including whiteflies and the TYLCV they spreads.

  19. Whitefly population dynamics and evaluation of whitefly-transmitted tomato yellow leaf curl virus (TYLCV)-resistant tomato genotypes as whitefly and TYLCV reservoirs.

    PubMed

    Srinivasan, Rajagopalbabu; Riley, David; Diffie, Stan; Sparks, Alton; Adkins, Scott

    2012-08-01

    Sweetpotato whitefly, Bemisia tabaci (Gennadius), and whitefly-transmitted tomato yellow leaf curl virus (TYLCV) are major threats to tomato production in the southeastern United States. TYLCV was introduced to Florida from the Caribbean islands and has spread to other southern states of the United States. In Georgia, in recent years, the incidence of TYLCV has been steadily increasing. Studies were conducted to monitor population dynamics of whiteflies in the vegetable production belt of Georgia, to evaluate TYLCV-resistant genotypes against whiteflies and TYLCV, and to assess the potential role of resistant genotypes in TYLCV epidemiology. Monitoring studies indicated that the peak incidence of whiteflies varied seasonally from year to year. In general, whitefly populations were not uniformly distributed. Tomato genotypes exhibited minor differences in their ability to support whitefly populations. TYLCV symptoms were visually undetectable in all but one resistant genotype. The infection rates (visually) in susceptible genotypes ranged from 40 to 87%. Greenhouse inoculations with viruliferous whiteflies followed by polymerase chain reaction (PCR) indicated that up to 100% of plants of resistant genotypes were infected, although predominantly symptomless. TYLCV acquisition by whiteflies from TYLCV-infected genotypes was tested by PCR; TYLCV acquisition rates from resistant genotypes were less than from susceptible genotypes. Nevertheless, this difference did not influence TYLCV transmission rates from resistant to susceptible genotypes. Results emphasize that resistant genotypes can serve as TYLCV and whitefly reservoirs and potentially influence TYLCV epidemics.

  20. Cestrum yellow leaf curling virus (CmYLCV) promoter: a new strong constitutive promoter for heterologous gene expression in a wide variety of crops.

    PubMed

    Stavolone, Livia; Kononova, Maria; Pauli, Sandra; Ragozzino, Antonio; de Haan, Peter; Milligan, Steve; Lawton, Kay; Hohn, Thomas

    2003-11-01

    Appropriately regulated gene expression requires a suitable promoter. A number of promoters have been isolated and shown to be functional in plants, but only a few of them activate transcription of transgenes at high levels constitutively. We report here the cloning and characterization of a novel, constitutively expressed promoter isolated from Cestrum yellow leaf curling virus (CmYLCV), a double-stranded DNA plant pararetrovirus belonging to the Caulimoviridae family. The CmYLCV promoter is highly active in callus, meristems and vegetative and reproductive tissues in Arabidopsis thaliana, Nicotiana tabacum, Lycopersicon esculentum, Zea mays and Oryza sativa. Furthermore, the level of expression is comparable to, or higher than, that from the CaMV 35S, the 'super-promoter' or the maize ubiquitin 1 promoters, three frequently used promoters in agricultural biotechnology. The heritable, strong and constitutive activity in both monocotyledonous and dicotyledonous plants, combined with the extremely narrow CmYLCV host range, makes the CmYLCV promoter an attractive tool for regulating transgene expression in a wide variety of plant species.

  1. PCR-RFLP-based typing for differentiation of Tomato yellow leaf curl virus (TYLCV) genotypes from infected host plants in Korea.

    PubMed

    Oh, Sung; Kim, Seongdae; Vinod, Nagarajan; Koo, Jung Mo; Jang, Kyung Min; Choi, Chang Won; Kim, Seong Hwan; Kim, Young Shik

    2013-12-01

    A polymerase chain reaction (PCR) using two sets of primers designed from published Tomato yellow leaf curl virus (TYLCV) genomes was developed to distinguish from the TYLCV-IL groups. The specificity of the two sets of primers was proven by testing against control TYLCV genomes and the symptomatic leaves of 34 different tomato cultivars naturally infected with TYLCV in greenhouses. One set for TYLCV-IL strain-specific primers (TYLCV-UNI-F and TYLCV-UNI-R) amplified full-length genome fragments from all the 34 tomato cultivars. Another set for TYLCV-IL group-II strain-specific primers (TYLCV-GPII-F and TYLCV-GPII-R) amplified target DNA fragments from only 9 tomato cultivars. Digestion by BglII and EcoRV of the PCR amplicons produced restriction fragment length polymorphism pattern that distinguished the TYLCV-IL group-I with two fragments from the TYLCV-IL group-II with no digested fragment. PCR coupled with BglII and EcoRV digestion confirmed that the 9 tomato cultivars were infected with the TYLCV-IL group-II and the remained 25 tomato cultivars were infected with the TYLCV-IL group-I.

  2. Evaluation of management strategies for bean leaf beetles (Coleoptera: Chrysomelidae) and Bean pod mottle virus (Comoviridae) in soybean.

    PubMed

    Bradshaw, Jeffrey D; Rice, Marlin E; Hill, John H

    2008-08-01

    Cerotoma trifurcata Förster (Coleoptera: Chrysomelidae) and Bean pod mottle virus (Comoviridae) (BPMV) both can reduce yield and seed quality of soybean, Glycine max (L.) Merr. Field experiments were conducted to evaluate the effects of systemic, seed-applied, and foliar-applied insecticides for the management of this pest complex at three locations in central, northeastern, and northwestern Iowa during 2002-2004. Seed-applied insecticide was evaluated according to a currently recommended management program for Iowa (i.e., insecticide applications that target emerging overwintered beetles, F0, and the first seasonal generation, F1 ). The experimental treatments included seed-applied (thiamethoxam, 0.3-0.5 g [AI] kg(-1)] or clothianidin, 47.32 ml [AI] kg(-1)) and foliar-applied (A-cyhalothrin, 16.83-28.05 g [AI] ha(-1)) or esfenvalerate (43.74-54.69 g [AI] ha(-1)) insecticides. Applications of the foliar insecticides were timed to target F0, F1 or both F0 and F1 populations of C. trifurcata. Our results confirm that insecticides timed at F0 and F1 populations of C. trifurcata can reduce vector populations throughout the growing season, provide limited reduction in virus incidence, and improve both yield and seed coat color. Furthermore, seed-applied insecticides may be the more reliable option for an F0-targeted insecticide if used within this management strategy. An F0-targeted insecticide by itself only gave a yield improvement in one out of eight location-years. However, by adding an F1-targeted insecticide, there was a yield gain of 1.42-1.67 quintal ha(-1), based on contrast comparisons at three location-years.

  3. Effect of herbivore damage on broad leaf motion in wind

    NASA Astrophysics Data System (ADS)

    Burnett, Nicholas; Kothari, Adit

    2015-11-01

    Terrestrial plants regularly experience wind that imposes aerodynamic forces on the plants' leaves. Passive leaf motion (e.g. fluttering) and reconfiguration (e.g. rolling into a cone shape) in wind can affect the drag on the leaf. In the study of passive leaf motion in wind, little attention has been given to the effect of herbivory. Herbivores may alter leaf motion in wind by making holes in the leaf. Also, a small herbivore (e.g. snail) on a leaf can act as a point mass, thereby affecting the leaf's motion in wind. Conversely, accelerations imposed on an herbivore sitting on a leaf by the moving leaf may serve as a defense by dislodging the herbivore. In the present study, we investigated how point masses (>1 g) and holes in leaves of the tuliptree affected passive leaf motion in turbulent winds of 1 and 5 m s-1. Leaf motion was unaffected by holes in the leaf surface (about 10% of leaf area), but an herbivore's mass significantly damped the accelerations of fluttering leaves. These results suggest that an herbivore's mass, but not the damage it inflicts, can affect leaf motion in the wind. Furthermore, the damping of leaf fluttering from an herbivore's mass may prevent passive leaf motions from being an effective herbivore defense.

  4. Evaluation of cotton leaf curl virus resistance in BC1, BC2, and BC3 progenies from an interspecific cross between Gossypium arboreum and Gossypium hirsutum.

    PubMed

    Nazeer, Wajad; Tipu, Abdul Latif; Ahmad, Saghir; Mahmood, Khalid; Mahmood, Abid; Zhou, Baoliang

    2014-01-01

    Cotton leaf curl virus disease (CLCuD) is an important constraint to cotton production. The resistance of G. arboreum to this devastating disease is well documented. In the present investigation, we explored the possibility of transferring genes for resistance to CLCuD from G. arboreum (2n = 26) cv 15-Mollisoni into G. hirsutum (2n = 52) cv CRSM-38 through conventional breeding. We investigated the cytology of the BC1 to BC3 progenies of direct and reciprocal crosses of G. arboreum and G. hirsutum and evaluated their resistance to CLCuD. The F1 progenies were completely resistant to this disease, while a decrease in resistance was observed in all backcross generations. As backcrossing progressed, the disease incidence increased in BC1 (1.7-2.0%), BC2 (1.8-4.0%), and BC3 (4.2-7.0%). However, the disease incidence was much lower than that of the check variety CIM-496, with a CLCuD incidence of 96%. Additionally, the disease incidence percentage was lower in the direct cross 2(G. arboreum)×G. hirsutum than in that of G. hirsutum×G. arboreum. Phenotypic resemblance of BC1 ∼BC3 progenies to G. arboreum confirmed the success of cross between the two species. Cytological studies of CLCuD-resistant plants revealed that the frequency of univalents and multivalents was high in BC1, with sterile or partially fertile plants, but low in BC2 (in both combinations), with shy bearing plants. In BC3, most of the plants exhibited normal bearing ability due to the high frequency of chromosome associations (bivalents). The assessment of CLCuD through grafting showed that the BC1 to BC3 progenies were highly resistant to this disease. Thus, this study successfully demonstrates the possibility of introgressing CLCuD resistance genes from G. arboreum to G. hirsutum.

  5. Evaluation of Cotton Leaf Curl Virus Resistance in BC1, BC2, and BC3 Progenies from an Interspecific Cross between Gossypium arboreum and Gossypium hirsutum

    PubMed Central

    Nazeer, Wajad; Tipu, Abdul Latif; Ahmad, Saghir; Mahmood, Khalid; Mahmood, Abid; Zhou, Baoliang

    2014-01-01

    Cotton leaf curl virus disease (CLCuD) is an important constraint to cotton production. The resistance of G. arboreum to this devastating disease is well documented. In the present investigation, we explored the possibility of transferring genes for resistance to CLCuD from G. arboreum (2n = 26) cv 15-Mollisoni into G. hirsutum (2n = 52) cv CRSM-38 through conventional breeding. We investigated the cytology of the BC1 to BC3 progenies of direct and reciprocal crosses of G. arboreum and G. hirsutum and evaluated their resistance to CLCuD. The F1 progenies were completely resistant to this disease, while a decrease in resistance was observed in all backcross generations. As backcrossing progressed, the disease incidence increased in BC1 (1.7–2.0%), BC2 (1.8–4.0%), and BC3 (4.2–7.0%). However, the disease incidence was much lower than that of the check variety CIM-496, with a CLCuD incidence of 96%. Additionally, the disease incidence percentage was lower in the direct cross 2(G. arboreum)×G. hirsutum than in that of G. hirsutum×G. arboreum. Phenotypic resemblance of BC1 ∼BC3 progenies to G. arboreum confirmed the success of cross between the two species. Cytological studies of CLCuD-resistant plants revealed that the frequency of univalents and multivalents was high in BC1, with sterile or partially fertile plants, but low in BC2 (in both combinations), with shy bearing plants. In BC3, most of the plants exhibited normal bearing ability due to the high frequency of chromosome associations (bivalents). The assessment of CLCuD through grafting showed that the BC1 to BC3 progenies were highly resistant to this disease. Thus, this study successfully demonstrates the possibility of introgressing CLCuD resistance genes from G. arboreum to G. hirsutum. PMID:25372141

  6. Development of a salicylic acid inducible minimal sub-genomic transcript promoter from Figwort mosaic virus with enhanced root- and leaf-activity using TGACG motif rearrangement.

    PubMed

    Kumar, Deepak; Patro, Sunita; Ghosh, Jayasish; Das, Abhimanyu; Maiti, Indu B; Dey, Nrisingha

    2012-07-15

    In Figwort mosaic virus sub-genomic transcript promoter (F-Sgt), function of the TGACG-regulatory motif, was investigated in the background of artificially designed promoter sequences. The 131bp (FS, -100 to +31) long F-Sgt promoter sequence containing one TGACG motif [FS-(TGACG)] was engineered to generate a set of three modified promoter constructs: [FS-(TGACG)(2), containing one additional TGACG motif at 7 nucleotides upstream of the original one], [FS-(TGACG)(3), containing two additional TGACG motifs at 7 nucleotides upstream and two nucleotides downstream of the original one] and [FS-(TGCTG)(mu), having a mutated TGACG motif]. EMSA and foot-printing analysis confirmed binding of tobacco nuclear factors with modified TGACG motif/s. The transcription-activation of the GUS gene by the TGACG motif/s in above promoter constructs was examined in transgenic tobacco and Arabidopsis plants and observed that the transcription activation was affected by the spacing/s and number/s of the TGACG motif/s. The FS-(TGACG)(2) promoter showed strongest root-activity compared to other modified and CaMV35S promoters. Also under salicylic acid (SA) stress, the leaf-activity of the said promoter was further enhanced. All above findings were confirmed by real-time and semi-qRT PCR analysis. Taken together, these results clearly demonstrated that the TGACG motif plays an important role in inducing the root-specific expression of the F-Sgt promoter. This study advocates the importance of genetic manipulation of functional cis-motif for amending the tissue specificity of a plant promoter. SA inducible FS-(TGACG)(2) promoter with enhanced activity could be a useful candidate promoter for developing plants with enhanced crop productivity.

  7. Leaf Activities.

    ERIC Educational Resources Information Center

    Mingie, Walter

    Leaf activities can provide a means of using basic concepts of outdoor education to learn in elementary level subject areas. Equipment needed includes leaves, a clipboard with paper, and a pencil. A bag of leaves may be brought into the classroom if weather conditions or time do not permit going outdoors. Each student should pick a leaf, examine…

  8. A recombinant Tobacco curly shoot virus causes leaf curl disease in tomato in a north-eastern state of India and has potentiality to trans-replicate a non-cognate betasatellite.

    PubMed

    Shilpi, S; Kumar, Alok; Biswas, S; Roy, Anirban; Mandal, Bikash

    2015-02-01

    Leaf curl disease is a serious constraint in tomato production throughout India. Several begomoviruses were reported from different parts of the country; however, identity of begomovirus associated with leaf curl disease in tomato in north-eastern states of India was obscured. In the present study, the complete genome of an isolate (To-Ag-1) of begomovirus was generated from a leaf curl sample collected from Tripura state. However, no DNA-B and betasatellite were detected in the field samples. The genome of To-Ag-1 isolate contained 2,755 nucleotides that shared 94.7 % sequence identity with Tobacco curly shoot virus (TbCSV) and 71.3-90.1 % sequence identity with the other tomato-infecting begomoviruses occurring in the Indian subcontinent. Several inter-specific recombination events among different tomato-infecting begomoviruses from India and intra-specific recombination among different isolates of TbCSV reported from China were observed in the genome of To-Ag-1 isolate. Agroinoculation of the virus alone produced leaf curl symptoms in tomato and Nicotiana benthamiana. However, co-inoculation with a non-cognate betasatellite, Croton yellow vein mosaic betasatellite (CroYVMB) with the TbCSV resulted in increased severity of the symptoms both in tomato and N. benthamiana. Systemic distribution of the TbCSV and CroYVMB was detected in the newly developed leaves of tobacco and tomato, which showed ability of TbCSV to trans-replicate CroYVMB. The present study for the first time provides evidence of occurrence of TbCSV in tomato in north-eastern region of India and showed increased virulence of TbCSV with a non-cognate betasatellite.

  9. Understanding Rolle's Theorem

    ERIC Educational Resources Information Center

    Parameswaran, Revathy

    2009-01-01

    This paper reports on an experiment studying twelfth grade students' understanding of Rolle's Theorem. In particular, we study the influence of different concept images that students employ when solving reasoning tasks related to Rolle's Theorem. We argue that students' "container schema" and "motion schema" allow for rich…

  10. Other Viruses and Viruslike Agents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The diseases reported under 'Virus and Virus-like Agents' in the first volume of this compendium, with the exception of Cherry rasp leaf virus and Rubus chinese seed-borne virus, should be considered oddities since there are no known type isolates available for these reported viruses. Without a po...

  11. Project LEAF

    EPA Pesticide Factsheets

    Project LEAF has a goal of educating farmworkers about how to reduce pesticide exposure to their families from pesticide residues they may be inadvertently taking home on their clothing, etc. Find outreach materials.

  12. OsLBD3-7 Overexpression Induced Adaxially Rolled Leaves in Rice

    PubMed Central

    Zhang, Chunyu; Shao, Qinghao; Liu, Jun; Liu, Bin; Li, Hongyu

    2016-01-01

    Appropriate leaf rolling enhances erect-leaf habits and photosynthetic efficiency, which consequently improves grain yield. Here, we reported the novel lateral organ boundaries domain (LBD) gene OsLBD3-7, which is involved in the regulation of leaf rolling. OsLBD3-7 works as a transcription activator and its protein is located on the plasma membrane and in the nucleus. Overexpression of OsLBD3-7 leads to narrow and adaxially rolled leaves. Microscopy of flag leaf cross-sections indicated that overexpression of OsLBD3-7 led to a decrease in both bulliform cell size and number. Transcriptional analysis showed that key genes that had been reported to be negative regulators of bulliform cell development were up-regulated in transgenic plants. These results indicated that OsLBD3-7 might acts as an upstream regulatory gene of bulliform cell development to regulate leaf rolling, which will give more insights on the leaf rolling regulation mechanism. PMID:27258066

  13. Effect of Roll Material on Surface Quality of Rolled Aluminum

    NASA Astrophysics Data System (ADS)

    Zhao, Qi

    The surface defects of aluminum alloys that have undergone hot rolling were studied. The effects of different roll materials, of the number of rolling passes and of lubrication on surface defects of hot rolled aluminum alloys were investigated by laboratory hot rolling. Two different aluminum alloys, Al-Mn and Al-Mg, were each rolled against three different steel alloy rolls, AISI 52100, AISI 440C and AISI D2. The results showed that different roll materials do affect the morphology of the mating aluminum alloy surface with apparent surface defects, which included magnesium and oxygen rich dark regions on both alloys. The carbide protrusions in 440C and D2 steel rolls are confirmed to be responsible for the dark, rich magnesium and oxygen regions on both the rolled Al-Mn and Al-Mg alloy surfaces. As the number of passes increases, Mg and O deposit in the form of patches and grain boundaries near the surface area.

  14. Leaf Development

    PubMed Central

    Tsukaya, Hirokazu

    2002-01-01

    The shoot system is the basic unit of development of seed plants and is composed of a leaf, a stem, and a lateral bud that differentiates into a lateral shoot. The most specialized organ in angiosperms, the flower, can be considered to be part of the same shoot system since floral organs, such as the sepal, petal, stamen, and carpel, are all modified leaves. Scales, bracts, and certain kinds of needle are also derived from leaves. Thus, an understanding of leaf development is critical to an understanding of shoot development. Moreover, leaves play important roles in photosynthesis, respiration and photoperception. Thus, a full understanding of leaves is directly related to a full understanding of seed plants. The details of leaf development remain unclear. The difficulties encountered in studies of leaf development, in particular in dicotyledonous plants such as Arabidopsis thaliana (L.) Henyn., are derived from the complex process of leaf development, during which the division and elongation of cells occur at the same time and in the same region of the leaf primordium (Maksymowych, 1963; Poethig and Sussex, 1985). Thus, we cannot divide the entire process into unit processes in accordance with the tenets of classical anatomy. Genetic approaches in Arabidopsis, a model plant (Meyerowitz and Pruitt, 1985), have provided a powerful tool for studies of mechanisms of leaf development in dicotyledonous plants, and various aspects of the mechanisms that control leaf development have been revealed in recent developmental and molecular genetic studies of Arabidopsis (for reviews, see Tsukaya, 1995 and 1998; Van Lijsebettens and Clarke, 1998; Sinha, 1999; Van Volkenburgh, 1999; Tsukaya, 2000; Byrne et al., 2001; Dengler and Kang, 2001; Dengler and Tsukaya, 2001; Tsukaya, 2001). In this review, we shall examine the information that is currently available about various mechanisms of leaf development in Arabidopsis. Vascular patterning is also an important factor in the

  15. Scavenging of reactive oxygen species in apoplastic and symplastic areas of rolled leaves in Ctenanthe setosa under drought stress.

    PubMed

    Saruhan, Neslihan; Terzi, Rabiye; Sağlam, Aykut; Kadioğlu, Asim

    2010-09-01

    The correspondence among apoplastic and symplastic antioxidant status, stomatal conductance and water potential was investigated during leaf rolling in Ctenanthe setosa (Rosc.) Eichler (Marantaceae) under drought stress. Apoplastic and symplastic extractions of leaf and petiole were performed at different visual leaf rolling scores from 1 to 4 (1 is unrolled, 4 is tightly rolled and the others are intermediate form). In the leaf symplast, the highest changes were found in catalase (CAT) and guaiacol peroxidase (GPX) activities when compared to score 1 during leaf rolling. No significant change was observed in superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities in the symplast of leaf during the rolling. The same phenomenon was also present in the symplast of petiole except APX activity. In the leaf apoplast, the highest increase occurred in APX and GPX activities, whilst a slight increase in CAT and SOD activities. In the apoplast of petiole, the highest increment was found only in GPX activity, while there were small increases in SOD, APX and CAT activities. Hydrogen peroxide content increased up to score 3 in the apoplast and symplast of leaf and petiole but then slightly decreased. Also, superoxide production increased in the leaf and petiole apoplast but its quantity in the apoplast was much more than that of the symplast. On the other hand, NAD(P)H oxidase activity increased in the leaf but no change was observed in the petiole. In conclusion, as a result of water deficit during leaf rolling antioxidant enzymes are induced to scavenging of ROS produced in symplast and apoplast.

  16. Leaf Development

    PubMed Central

    2013-01-01

    Leaves are the most important organs for plants. Without leaves, plants cannot capture light energy or synthesize organic compounds via photosynthesis. Without leaves, plants would be unable perceive diverse environmental conditions, particularly those relating to light quality/quantity. Without leaves, plants would not be able to flower because all floral organs are modified leaves. Arabidopsis thaliana is a good model system for analyzing mechanisms of eudicotyledonous, simple-leaf development. The first section of this review provides a brief history of studies on development in Arabidopsis leaves. This history largely coincides with a general history of advancement in understanding of the genetic mechanisms operating during simple-leaf development in angiosperms. In the second section, I outline events in Arabidopsis leaf development, with emphasis on genetic controls. Current knowledge of six important components in these developmental events is summarized in detail, followed by concluding remarks and perspectives. PMID:23864837

  17. Viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lytic bacteriophages, viruses which infect and lyse bacterial cells, can provide a natural method to reduce bacterial pathogens on produce commodities. The use of multi-phage cocktails is most likely to be effective against bacterial pathogens on produce commodities, and minimize the development of...

  18. Virion Stability Is Important for the Circulative Transmission of Tomato Yellow Leaf Curl Sardinia Virus by Bemisia tabaci, but Virion Access to Salivary Glands Does Not Guarantee Transmissibility▿ †

    PubMed Central

    Caciagli, Piero; Medina Piles, Vicente; Marian, Daniele; Vecchiati, Manuela; Masenga, Vera; Mason, Giovanna; Falcioni, Tania; Noris, Emanuela

    2009-01-01

    The capsid protein (CP) of the monopartite begomovirus Tomato yellow leaf curl Sardinia virus (TYLCSV), family Geminiviridae, is indispensable for plant infection and vector transmission. A region between amino acids 129 and 152 is critical for virion assembly and insect transmissibility. Two previously described mutants, one with a double Q129P Q134H mutation (PNHD) and another with a further D152E change (PNHE), were found nontransmissible (NT). Another NT mutant with a single N130D change (QDQD) was retrieved from a new mutational analysis. In this study, these three NT mutants and the wild-type (wt) virus were compared in their relationships with the whitefly vector Bemisia tabaci and the nonvector Trialeurodes vaporariorum. Retention kinetics of NT mutants were analyzed by quantitative dot blot hybridization in whiteflies fed on infected plants. The QDQD mutant, whose virions appeared nongeminate following purification, was hardly detectable in either whitefly species at any sampling time. The PNHD mutant was acquired and circulated in both whitefly species for up to 10 days, like the wt virus, while PNHE circulated in B. tabaci only. Using immunogold labeling, both PNHD and PNHE CPs were detected in B. tabaci salivary glands (SGs) like the wt virus, while no labeling was found in any whitefly tissue with the QDQD mutant. Significant inhibition of transmission of the wt virus was observed after prior feeding of the insects on plants infected with the PNHE mutant, but not on plants infected with the other mutants. Virion stability and ability to cross the SG barrier are necessary for TYLCSV transmission, but interactions with molecular components inside the SGs are also critical for transmissibility. PMID:19321611

  19. Spray Rolling Aluminum Strip

    SciTech Connect

    Lavernia, E.J.; Delplanque, J-P; McHugh, K.M.

    2006-05-10

    Spray forming is a competitive low-cost alternative to ingot metallurgy for manufacturing ferrous and non-ferrous alloy shapes. It produces materials with a reduced number of processing steps, while maintaining materials properties, with the possibility of near-net-shape manufacturing. However, there are several hurdles to large-scale commercial adoption of spray forming: 1) ensuring strip is consistently flat, 2) eliminating porosity, particularly at the deposit/substrate interface, and 3) improving material yield. Through this program, a new strip/sheet casting process, termed spray rolling, has been developed, which is an innovative manufacturing technique to produce aluminum net-shape products. Spray rolling combines the benefits of twin-roll casting and conventional spray forming, showing a promising potential to overcome the above hurdles associated with spray forming. Spray rolling requires less energy and generates less scrap than conventional processes and, consequently, enables the development of materials with lower environmental impacts in both processing and final products. Spray Rolling was developed as a collaborative project between the University of California-Davis, the Colorado School of Mines, the Idaho National Engineering and Environmental Laboratory, and an industry team. The following objectives of this project were achieved: (1) Demonstration of the feasibility of the spray rolling process at the bench-scale level and evaluation of the materials properties of spray rolled aluminum strip alloys; and (2) Demonstration of 2X scalability of the process and documentation of technical hurdles to further scale up and initiate technology transfer to industry for eventual commercialization of the process.

  20. Wear of hot rolling mill rolls: An overview

    NASA Astrophysics Data System (ADS)

    Spuzic, S.; Strafford, K. N.; Subramanian, C.; Savage, G.

    1994-08-01

    Rolling is today one of the most important industrial processes because a greater volume of material is worked by rolling than by any other technique. Roll wear is a multiplex process where mechanical and thermal fatigue combines with impact, abrasion, adhesion and corrosion, which all depend on system interactions rather than material characteristics only. The situation is more complicated in section rolling because of the intricacy of roll geometry. Wear variables and modes are reviewed along with published methods and models used in the study and testing of roll wear. This paper reviews key aspects of roll wear control - roll material properties, roll pass design, and system factors such as temperature, loads and sliding velocity. An overview of roll materials is given including adamites, high Cr materials, high speed tool steels and compound rolls. Non-uniform wear, recognized as the most detrimental phenomenon in section rolling, can be controlled by roll pass design. This can be achieved by computer-aided graphical and statistical analyses of various pass series. Preliminary results obtained from pilot tests conducted using a two-disc hot wear rig and a scratch tester are discussed.

  1. Identification of a New Cotton Disease Caused by an Atypical Cotton Leafroll Dwarf Virus in Argentina.

    PubMed

    Agrofoglio, Yamila C; Delfosse, Verónica C; Casse, María F; Hopp, Horacio E; Kresic, Iván Bonacic; Distéfano, Ana J

    2017-03-01

    An outbreak of a new disease occurred in cotton (Gossypium hirsutum) fields in northwest Argentina starting in the 2009-10 growing season and is still spreading steadily. The characteristic symptoms of the disease included slight leaf rolling and a bushy phenotype in the upper part of the plant. In this study, we determined the complete nucleotide sequences of two independent virus genomes isolated from cotton blue disease (CBD)-resistant and -susceptible cotton varieties. This virus genome comprised 5,866 nucleotides with an organization similar to that of the genus Polerovirus and was closely related to cotton leafroll dwarf virus, with protein identity ranging from 88 to 98%. The virus was subsequently transmitted to a CBD-resistant cotton variety using Aphis gossypii and symptoms were successfully reproduced. To study the persistence of the virus, we analyzed symptomatic plants from CBD-resistant varieties from different cotton-growing fields between 2013 and 2015 and showed the presence of the same virus strain. In addition, a constructed full-length infectious cDNA clone from the virus caused disease symptoms in systemic leaves of CBD-resistant cotton plants. Altogether, the new leafroll disease in CBD-resistant cotton plants is caused by an atypical cotton leafroll dwarf virus.

  2. A new virus discovered by immunocapture of double-stranded RNA, a rapid method for virus enrichment in metagenomic studies.

    PubMed

    Blouin, Arnaud G; Ross, Howard A; Hobson-Peters, Jody; O'Brien, Caitlin A; Warren, Ben; MacDiarmid, Robin

    2016-09-01

    Next-generation sequencing technologies enable the rapid identification of viral infection of diseased organisms. However, despite a consistent decrease in sequencing costs, it is difficult to justify their use in large-scale surveys without a virus sequence enrichment technique. As the majority of plant viruses have an RNA genome, a common approach is to extract the double-stranded RNA (dsRNA) replicative form, to enrich the replicating virus genetic material over the host background. The traditional dsRNA extraction is time-consuming and labour-intensive. We present an alternative method to enrich dsRNA from plant extracts using anti-dsRNA monoclonal antibodies in a pull-down assay. The extracted dsRNA can be amplified by reverse transcriptase-polymerase chain reaction and sequenced by next-generation sequencing. In our study, we have selected three distinct plant hosts: Māori potato (Solanum tuberosum), rengarenga (Arthropodium cirratum) and broadleaved dock (Rumex obtusifolius) representing a cultivated crop, a New Zealand-native ornamental plant and a weed, respectively. Of the sequence data obtained, 31-74% of the reads were of viral origin, and we identified five viruses including Potato virus Y and Potato virus S in potato; Turnip mosaic virus in rengarenga (a new host record); and in the dock sample Cherry leaf roll virus and a novel virus belonging to the genus Macluravirus. We believe that this new assay represents a significant opportunity to upscale virus ecology studies from environmental, primary industry and/or medical samples.

  3. Stochastic disks that roll

    NASA Astrophysics Data System (ADS)

    Holmes-Cerfon, Miranda

    2016-11-01

    We study a model of rolling particles subject to stochastic fluctuations, which may be relevant in systems of nano- or microscale particles where rolling is an approximation for strong static friction. We consider the simplest possible nontrivial system: a linear polymer of three disks constrained to remain in contact and immersed in an equilibrium heat bath so the internal angle of the polymer changes due to stochastic fluctuations. We compare two cases: one where the disks can slide relative to each other and the other where they are constrained to roll, like gears. Starting from the Langevin equations with arbitrary linear velocity constraints, we use formal homogenization theory to derive the overdamped equations that describe the process in configuration space only. The resulting dynamics have the formal structure of a Brownian motion on a Riemannian or sub-Riemannian manifold, depending on if the velocity constraints are holonomic or nonholonomic. We use this to compute the trimer's equilibrium distribution with and without the rolling constraints. Surprisingly, the two distributions are different. We suggest two possible interpretations of this result: either (i) dry friction (or other dissipative, nonequilibrium forces) changes basic thermodynamic quantities like the free energy of a system, a statement that could be tested experimentally, or (ii) as a lesson in modeling rolling or friction more generally as a velocity constraint when stochastic fluctuations are present. In the latter case, we speculate there could be a "roughness" entropy whose inclusion as an effective force could compensate the constraint and preserve classical Boltzmann statistics. Regardless of the interpretation, our calculation shows the word "rolling" must be used with care when stochastic fluctuations are present.

  4. METHOD OF ROLLING URANIUM

    DOEpatents

    Smith, C.S.

    1959-08-01

    A method is described for rolling uranium metal at relatively low temperatures and under non-oxidizing conditions. The method involves the steps of heating the uranium to 200 deg C in an oil bath, withdrawing the uranium and permitting the oil to drain so that only a thin protective coating remains and rolling the oil coated uranium at a temperature of 200 deg C to give about a 15% reduction in thickness at each pass. The operation may be repeated to accomplish about a 90% reduction without edge cracking, checking or any appreciable increase in brittleness.

  5. Rolling through a vacuum

    NASA Astrophysics Data System (ADS)

    van der Schaar, Jan Pieter; Yang, I.-Sheng

    2013-12-01

    We clarify under what conditions slow-roll inflation can continue almost undisturbed, while briefly evolving through a (semi-classically) metastable false vacuum. Furthermore, we look at potential signatures in the primordial power spectrum that could point towards the existence of traversed metastable false vacua. Interestingly, the theoretical constraints for the existence of traversable metastable vacua imply that Planck should be able to detect the resulting features in the primordial power spectrum. In other words, if Planck does not see features this immediately implies the non-existence of metastable false vacua rolled through during the inflationary epoch.

  6. Mapping Quantitative Trait Loci of Resistance to Tomato Spotted Wilt Virus and Leaf Spots in a Recombinant Inbred Line Population of Peanut (Arachis hypogaea L.) from SunOleic 97R and NC94022

    PubMed Central

    Feng, Suping; Qiao, Lixian; Culbreath, Albert K.; Kale, Sandip; Wang, Jianping; Holbrook, C. Corley; Zhuang, Weijian; Varshney, Rajeev K.; Guo, Baozhu

    2016-01-01

    Peanut is vulnerable to a range of diseases, such as Tomato spotted wilt virus (TSWV) and leaf spots which will cause significant yield loss. The most sustainable, economical and eco-friendly solution for managing peanut diseases is development of improved cultivars with high level of resistance. We developed a recombinant inbred line population from the cross between SunOleic 97R and NC94022, named as the S-population. An improved genetic linkage map was developed for the S-population with 248 marker loci and a marker density of 5.7 cM/loci. This genetic map was also compared with the physical map of diploid progenitors of tetraploid peanut, resulting in an overall co-linearity of about 60% with the average co-linearity of 68% for the A sub-genome and 47% for the B sub-genome. The analysis using the improved genetic map and multi-season (2010–2013) phenotypic data resulted in the identification of 48 quantitative trait loci (QTLs) with phenotypic variance explained (PVE) from 3.88 to 29.14%. Of the 48 QTLs, six QTLs were identified for resistance to TSWV, 22 QTLs for early leaf spot (ELS) and 20 QTLs for late leaf spot (LLS), which included four, six, and six major QTLs (PVE larger than 10%) for each disease, respectively. A total of six major genomic regions (MGR) were found to have QTLs controlling more than one disease resistance. The identified QTLs and resistance gene-rich MGRs will facilitate further discovery of resistance genes and development of molecular markers for these important diseases. PMID:27427980

  7. The C2 protein of tomato yellow leaf curl Sardinia virus acts as a pathogenicity determinant and a 16-amino acid domain is responsible for inducing a hypersensitive response in plants.

    PubMed

    Matić, Slavica; Pegoraro, Mattia; Noris, Emanuela

    2016-04-02

    The role of the C2 protein in the pathogenicity of tomato yellow leaf curl Sardinia virus (TYLCSV) was investigated. Here we report that Agrobacterium-mediated transient expression of TYLCSV C2 resulted in a strong hypersensitive response (HR) in Nicotiana benthamiana, N. tabacum, and Arabidopsis thaliana, with induction of plant cell death and production of H2O2. Since HR is not evident in plants infected by TYLCSV, it is expected that TYLCSV encodes a gene (or genes) that counters this response. HR was partially counteracted by co-agroinfiltration of TYLCSV V2 and Rep, leading to chlorotic reaction, with no HR development. Considering that the corresponding C2 protein of the closely related tomato yellow leaf curl virus (TYLCV) did not induce HR, alignment of the C2 proteins of TYLCSV and TYLCV were carried out and a hypervariable region of 16 amino acids was identified. Its role in the induction of HR was demonstrated using TYLCSV-TYLCV C2 chimeric genes, encoding two TYLCSV C2 variants with a complete (16 aa) or a partial (10 aa only) swap of the corresponding sequence of TYLCV C2. Furthermore, using NahG transgenic N. benthamiana lines compromised in the accumulation of salicylic acid (SA), a key regulator of HR, only a chlorotic response occurred in TYLCSV C2-infiltrated tissue, indicating that SA participates in such plant defense process. These findings demonstrate that TYLCSV C2 acts as a pathogenicity determinant and induces host defense responses controlled by the SA pathway.

  8. Aircraft roll steering command system

    NASA Technical Reports Server (NTRS)

    Lambregts, Antonius A. (Inventor)

    1985-01-01

    Aircraft roll command signals are generated as a function of the Microwave Landing System based azimuth, groundtrack, groundspeed and azimuth rate or range distance input parameters. On initial approach, roll command signals are inhibited until a minimum roll command requirement is met. As the aircraft approaches the centerline of the runway, the system reverts to a linear track control.

  9. Rolling Spot Welder

    NASA Technical Reports Server (NTRS)

    Wagner, Garret E.; Fonteyne, Steve L.

    1990-01-01

    Wheeled tool speeds tack-welding operations. Spotwelds foil to parts in preparation for brazing. Includes electrode wheel rolling across foil. Welding current in electrode pulsed as electrode moves along, making series of uniformly-spaced low-current spot welds.

  10. Diversity of beet curly top Iran virus isolated from different hosts in Iran.

    PubMed

    Gharouni Kardani, Sara; Heydarnejad, Jahangir; Zakiaghl, Mohammad; Mehrvar, Mohsen; Kraberger, Simona; Varsani, Arvind

    2013-06-01

    Beet curly top Iran virus (BCTIV) is a major pathogen of sugar beet in Iran. In order to study diversity of BCTIV, we sampled 68 plants in Iran during the summer of 2010 with curly top disease symptoms on beans (Phaseolus vulgaris), cowpeas (Vigna unguiculata), tomatoes (Solanum lycopersicum L.), sea beets (Beta vulgaris subsp. maritima), and sugar beets (Beta vulgaris). Plant samples showing leaf curling, yellowing, and/or swelling of veins on the lower leaf surfaces were collected from various fields in Khorasan Razavi, Northern Khorasan (north-eastern Iran), East Azarbayejan, West Azarbayejan (north-western Iran), and Fars (southern Iran) provinces. Using rolling circle amplification coupled with restriction digests, cloning, and Sanger sequencing, we determined the genomes of nine new BCTIV isolates from bean, cowpea, tomato, sea beet, and sugar beet in Iran. Our analysis reveals ~11 % diversity amongst BCTIV isolates and we detect evidence of recombination within these genomes.

  11. Mechanical inoculation of plant viruses.

    PubMed

    Hull, Roger

    2009-05-01

    This technique is for the mechanical inoculation of viruses to plants. It is used to diagnose a virus by its reactions in a variety of plant species, to test the infectivity of virus samples using local lesion hosts, and to propagate viruses. The virus preparation is rubbed onto the surface of the leaf in such a way as to break the surface cells without causing too much mechanical damage. The preparation of the virus sample, its application to the leaf, and the care of the plants before and after inoculation are described.

  12. Virus movement within grafted watermelon plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Watermelon production in Florida is impacted by several viruses including whitefly-transmitted Squash vein yellowing virus (SqVYV), Cucurbit yellow stunting disorder virus and Cucurbit leaf crumple virus, and aphid-transmitted Papaya ringspot virus type W (PRSV-W). While germplasm resistant to some...

  13. GRCop-84 Rolling Parameter Study

    NASA Technical Reports Server (NTRS)

    Loewenthal, William S.; Ellis, David L.

    2008-01-01

    This report is a section of the final report on the GRCop-84 task of the Constellation Program and incorporates the results obtained between October 2000 and September 2005, when the program ended. NASA Glenn Research Center (GRC) has developed a new copper alloy, GRCop-84 (Cu-8 at.% Cr-4 at.% Nb), for rocket engine main combustion chamber components that will improve rocket engine life and performance. This work examines the sensitivity of GRCop-84 mechanical properties to rolling parameters as a means to better define rolling parameters for commercial warm rolling. Experiment variables studied were total reduction, rolling temperature, rolling speed, and post rolling annealing heat treatment. The responses were tensile properties measured at 23 and 500 C, hardness, and creep at three stress-temperature combinations. Understanding these relationships will better define boundaries for a robust commercial warm rolling process. The four processing parameters were varied within limits consistent with typical commercial production processes. Testing revealed that the rolling-related variables selected have a minimal influence on tensile, hardness, and creep properties over the range of values tested. Annealing had the expected result of lowering room temperature hardness and strength while increasing room temperature elongations with 600 C (1112 F) having the most effect. These results indicate that the process conditions to warm roll plate and sheet for these variables can range over wide levels without negatively impacting mechanical properties. Incorporating broader process ranges in future rolling campaigns should lower commercial rolling costs through increased productivity.

  14. Tomato yellow leaf curl Sardinia virus-resistant tomato plants expressing the multifunctional N-terminal domain of the replication-associated protein show transcriptional changes resembling stress-related responses.

    PubMed

    Lucioli, Alessandra; Berardi, Alessandra; Gatti, Francesca; Tavazza, Raffaela; Pizzichini, Daniele; Tavazza, Mario

    2014-01-01

    The N-terminal domain (amino acids 1-130) of the replication-associated protein (Rep130 ) of Tomato yellow leaf curl Sardinia virus (TYLCSV) retains the ability of full-length Rep to localize to the nucleus and to down-regulate C1 transcription when ectopically expressed in plants, both functions being required to inhibit homologous viral replication. In this study, we analysed the effect of Rep130 expression on virus resistance and the plant transcriptome in the natural and agronomically important host species of TYLCSV, Solanum lycopersicum. Tomato plants accumulating high levels of Rep130 were generated and proved to be resistant to TYLCSV. Using an in vitro assay, we showed that plant-expressed Rep130 also retains the catalytic activity of Rep, thus supporting the notion that this protein domain is fully functional. Interestingly, Rep130 -expressing tomatoes were characterized by an altered transcriptional profile resembling stress-related responses. Notably, the serine-type protease inhibitor (Ser-PI) category was over-represented among the 20 up-regulated genes. The involvement of Rep130 in the alteration of host mRNA steady-state levels was confirmed using a distinct set of virus-resistant transgenic tomato plants expressing the same TYLCSV Rep130 , but from a different, synthetic, gene. Eight genes were found to be up-regulated in both types of transgenic tomato and two encoded Ser-PIs. Four of these eight genes were also up-regulated in TYLCSV-infected wild-type tomato plants. Implications with regard to the ability of this Rep domain to interfere with viral infections and to alter the host transcriptome are discussed.

  15. Walk and roll robot

    NASA Technical Reports Server (NTRS)

    Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

    2011-01-01

    A mobile robotic unit features a main body, a plurality of legs for supporting the main body on and moving the main body in forward and reverse directions about a base surface, and a drive assembly. According to an exemplary embodiment each leg includes a respective pivotal hip joint, a pivotal knee joint, and a wheeled foot adapted to roll along the base surface. Also according to an exemplary embodiments the drive assembly includes a motor operatively associated with the hip and knee joints and the wheeled foot for independently driving pivotal movement of the hip joint and the knee joint and rolling motion of the wheeled foot. The hip joint may include a ball-and-socket-type joint interconnecting top portion of the leg to the main body, such that the hip joint is adapted to pivot said leg in a direction transverse to a forward-and-reverse direction.

  16. Explicit Nonlinear Finite Element Geometric Analysis of Parabolic Leaf Springs under Various Loads

    PubMed Central

    Kong, Y. S.; Omar, M. Z.; Chua, L. B.; Abdullah, S.

    2013-01-01

    This study describes the effects of bounce, brake, and roll behavior of a bus toward its leaf spring suspension systems. Parabolic leaf springs are designed based on vertical deflection and stress; however, loads are practically derived from various modes especially under harsh road drives or emergency braking. Parabolic leaf springs must sustain these loads without failing to ensure bus and passenger safety. In this study, the explicit nonlinear dynamic finite element (FE) method is implemented because of the complexity of experimental testing A series of load cases; namely, vertical push, wind-up, and suspension roll are introduced for the simulations. The vertical stiffness of the parabolic leaf springs is related to the vehicle load-carrying capability, whereas the wind-up stiffness is associated with vehicle braking. The roll stiffness of the parabolic leaf springs is correlated with the vehicle roll stability. To obtain a better bus performance, two new parabolic leaf spring designs are proposed and simulated. The stress level during the loadings is observed and compared with its design limit. Results indicate that the newly designed high vertical stiffness parabolic spring provides the bus a greater roll stability and a lower stress value compared with the original design. Bus safety and stability is promoted, as well as the load carrying capability. PMID:24298209

  17. Shear Roll Mill Reactivation

    DTIC Science & Technology

    2012-09-13

    process equipment sprinkler protection systems , and the 5 psig steam supply serving the building heating and make-up air systems . It also included...control system can be run for maintenance and/or checkout while the fire alarm panel is bypassed. A sprinkler line and gate valve serving the Primac...the 440 v. electrical system providing power for process equipment motors, shear roll hydraulic pump motors, the air compressor motor, as well as

  18. Investigation of thermomechanical behavior of a work roll and of roll life in hot strip rolling

    NASA Astrophysics Data System (ADS)

    Sun, C. G.; Hwang, S. M.; Yun, C. S.; Chung, J. S.

    1998-09-01

    An integrated finite element-based model is presented for the prediction of the steady-state thermomechanical behavior of the roll-strip system and of roll life in hot strip rolling. The model is comprised of basic finite-element models, which are incorporated into an iterative-solution procedure to deal with the interdependence between the thermomechanical behavior of the strip and that of the work roll, which arises from roll-strip contact, as well as with the interdependence between the thermal and mechanical behavior. Comparison is made between the predictions and the measurements to assess solution accuracy. Then, the effect of various process parameters on the detailed aspects of thermomechanical behavior of the work roll and on roll life is investigated via a series of process simulations.

  19. Roll-to-Roll production of carbon nanotubes based supercapacitors

    NASA Astrophysics Data System (ADS)

    Zhu, Jingyi; Childress, Anthony; Karakaya, Mehmet; Roberts, Mark; Arcilla-Velez, Margarita; Podila, Ramakrishna; Rao, Apparao

    2014-03-01

    Carbon nanomaterials provide an excellent platform for electrochemical double layer capacitors (EDLCs). However, current industrial methods for producing carbon nanotubes are expensive and thereby increase the costs of energy storage to more than 10 Wh/kg. In this regard, we developed a facile roll-to-roll production technology for scalable manufacturing of multi-walled carbon nanotubes (MWNTs) with variable density on run-of-the-mill kitchen Al foils. Our method produces MWNTs with diameter (heights) between 50-100 nm (10-100 μm), and a specific capacitance as high as ~ 100 F/g in non-aqueous electrolytes. In this talk, the fundamental challenges involved in EDLC-suitable MWNT growth, roll-to-roll production, and device manufacturing will be discussed along with electrochemical characteristics of roll-to-roll MWNTs. Research supported by NSF CMMI Grant1246800.

  20. Ecosystem engineers on plants: indirect facilitation of arthropod communities by leaf-rollers at different scales.

    PubMed

    Vieira, Camila; Romero, Gustavo Q

    2013-07-01

    Ecosystem engineering is a process by which organisms change the distribution of resources and create new habitats for other species via non-trophic interactions. Leaf-rolling caterpillars can act as ecosystem engineers because they provide shelter to secondary users. In this study, we report the influence of leaf-rolling caterpillars on speciose tropical arthropod communities along both spatial scales (leaf-level and plant-level effects) and temporal scales (dry and rainy seasons). We predict that rolled leaves can amplify arthropod diversity at both the leaf and plant levels and that this effect is stronger in dry seasons, when arthropods are prone to desiccation. Our results show that the abundance, richness, and biomass of arthropods within several guilds increased up to 22-fold in naturally and artificially created leaf shelters relative to unaltered leaves. These effects were observed at similar magnitudes at both the leaf and plant scales. Variation in the shelter architecture (funnel, cylinders) did not influence arthropod parameters, as diversity, abundance, orbiomass, but rolled leaves had distinct species composition if compared with unaltered leaves. As expected, these arthropod parameters on the plants with rolled leaves were on average approximately twofold higher in the dry season. Empty leaf rolls and whole plants were rapidly recolonized by arthropods over time, implying a fast replacement of individuals; within 15-day intervals the rolls and plants reached a species saturation. This study is the first to examine the extended effects of engineering caterpillars as diversity amplifiers at different temporal and spatial scales. Because shelter-building caterpillars are ubiquitous organisms in tropical and temperate forests, they can be considered key structuring elements for arthropod communities on plants.

  1. The C2 Protein from the Geminivirus Tomato Yellow Leaf Curl Sardinia Virus Decreases Sensitivity to Jasmonates and Suppresses Jasmonate-Mediated Defences.

    PubMed

    Rosas-Díaz, Tábata; Macho, Alberto P; Beuzón, Carmen R; Lozano-Durán, Rosa; Bejarano, Eduardo R

    2016-01-15

    An increasing body of evidence points at a role of the plant hormones jasmonates (JAs) in determining the outcome of plant-virus interactions. Geminiviruses, small DNA viruses infecting a wide range of plant species worldwide, encode a multifunctional protein, C2, which is essential for full pathogenicity. The C2 protein has been shown to suppress the JA response, although the current view on the extent of this effect and the underlying molecular mechanisms is incomplete. In this work, we use a combination of exogenous hormone treatments, microarray analysis, and pathogen infections to analyze, in detail, the suppression of the JA response exerted by C2. Our results indicate that C2 specifically affects certain JA-induced responses, namely defence and secondary metabolism, and show that plants expressing C2 are more susceptible to pathogen attack. We propose a model in which C2 might interfere with the JA response at several levels.

  2. The C2 Protein from the Geminivirus Tomato Yellow Leaf Curl Sardinia Virus Decreases Sensitivity to Jasmonates and Suppresses Jasmonate-Mediated Defences

    PubMed Central

    Rosas-Díaz, Tábata; Macho, Alberto P.; Beuzón, Carmen R.; Lozano-Durán, Rosa; Bejarano, Eduardo R.

    2016-01-01

    An increasing body of evidence points at a role of the plant hormones jasmonates (JAs) in determining the outcome of plant-virus interactions. Geminiviruses, small DNA viruses infecting a wide range of plant species worldwide, encode a multifunctional protein, C2, which is essential for full pathogenicity. The C2 protein has been shown to suppress the JA response, although the current view on the extent of this effect and the underlying molecular mechanisms is incomplete. In this work, we use a combination of exogenous hormone treatments, microarray analysis, and pathogen infections to analyze, in detail, the suppression of the JA response exerted by C2. Our results indicate that C2 specifically affects certain JA-induced responses, namely defence and secondary metabolism, and show that plants expressing C2 are more susceptible to pathogen attack. We propose a model in which C2 might interfere with the JA response at several levels. PMID:27135228

  3. Ocimum sanctum leaf extract induces drought stress tolerance in rice

    PubMed Central

    Pandey, Veena; Ansari, M.W.; Tula, Suresh; Sahoo, R.K.; Bains, Gurdeep; Kumar, J.; Tuteja, Narendra; Shukla, Alok

    2016-01-01

    ABSTRACT Ocimum leaves are highly enriched in antioxidant components. Thus, its leaf extract, if applied in plants, is believed to efficiently scavenge ROS, thereby preventing oxidative damage under drought stress. Thus, the present study was performed in kharif 2013 and rabi 2014 season to evaluate the effect of aqueous leaf extract of Ocimum sanctum against drought stress in 2 rice genotype under glass house conditions. Here we show that various morpho- physiological (chlorophyll fluorescence, leaf rolling score, leaf tip burn, number of senesced leaves and total dry matter) and biochemical parameters (proline, malondialdehyde and superoxide dismutase content) were amended by Ocimum treatment in both the seasons. Application of Ocimum extract increased expression of dehydrin genes, while reducing expression of aquaporin genes in drought stressed rice plant. Thus, application of Ocimum leaf extract under drought stress can be suggested as a promising strategy to mitigate drought stress in economical, accessible and ecofriendly manner. PMID:26890603

  4. Proteome profile of maize (Zea Mays L.) leaf tissue at the flowering stage after long-term adjustment to rice black-streaked dwarf virus infection.

    PubMed

    Li, Kunpeng; Xu, Changzheng; Zhang, Juren

    2011-10-10

    Maize rough dwarf disease (MRDD) is a viral disease and causes great yield loss. To better understand the effects of MRDD on plant growth and metabolism, comparative proteomic analysis of leaves from virus-infected and normal plants was performed. In order to eliminate the interference of Ribulose-1, 5-bisphosphate carboxylase with low-abundance proteins, total proteins were pre-fractionated by 15% PEG and the proteins from supernatant and precipitated fractions were analyzed by 2-DE, subsequently. Out of approximately 1200 protein spots detected, less than 2% of the spots on the gels were overlapping between the fractions of precipitation and supernatant. We identified 91 differentially accumulated proteins that belong to multiple metabolic/biochemical pathways in plants. Further analysis of these identified proteins indicated that MRDD resulted in dramatic changes in the fundamental metabolism, including glycolysis and starch metabolism, and eventually the significant differences in morphology and development between virus-infected and normal plants. Moreover, MRDD occurrence increased the demands for G-proteins, antioxidant enzymes, lipoxygenases and UDP-glucosyltransferase BX9, which may play important roles in response of plant against virus infection. The results also suggested that MRDD is a complicated disease controlled by multigene participating in different pathways.

  5. Analysis of sequences from field samples reveals the presence of the recently described pepper vein yellows virus (genus Polerovirus) in six additional countries.

    PubMed

    Knierim, Dennis; Tsai, Wen-Shi; Kenyon, Lawrence

    2013-06-01

    Polerovirus infection was detected by reverse transcription polymerase chain reaction (RT-PCR) in 29 pepper plants (Capsicum spp.) and one black nightshade plant (Solanum nigrum) sample collected from fields in India, Indonesia, Mali, Philippines, Thailand and Taiwan. At least two representative samples for each country were selected to generate a general polerovirus RT-PCR product of 1.4 kb length for sequencing. Sequence analysis of the partial genome sequences revealed the presence of pepper vein yellows virus (PeVYV) in all 13 samples. A 1990 Australian herbarium sample of pepper described by serological means as infected with capsicum yellows virus (CYV) was identified by sequence analysis of a partial CP sequence as probably infected with a potato leaf roll virus (PLRV) isolate.

  6. Rolling cuff flexible bellows

    DOEpatents

    Lambert, Donald R.

    1985-01-01

    A flexible connector apparatus used to join two stiff non-deformable members, such as piping. The apparatus is provided with one or more flexible sections or assemblies each utilizing a bellows of a rolling cuff type connected between two ridge members, with the bellows being supported by a back-up ring, such that only the curved end sections of the bellows are unsupported. Thus, the bellows can be considered as being of a tube-shaped configuration and thus have high pressure resistance. The components of the flexible apparatus are sealed or welded one to another such that it is fluid tight.

  7. VIEW OF HANDOPERATED ROLLING MILLS ROLLING STANDS FROM LEFT TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF HAND-OPERATED ROLLING MILLS ROLLING STANDS FROM LEFT TO RIGHT: THREE HIGH; THREE HIGH; THREE HIGH; THREE HIGH (OPERATED AS A TWO-HIGH); TWO HIGH TWO HIGH MANUFACTURED BY BLAW-KNOX THREE HIGH MANUFACTURED BY LEWIS FOUNDRY AND MACHINE CO. - Cambria Iron Company, Gautier Works, 12" Mill, Clinton Street & Little Conemaugh River, Johnstown, Cambria County, PA

  8. First report of association of potato virus X and potato virus Y and 'Candidatus Phytoplasma trifolii' in brinjal in India.

    PubMed

    Kumar, Manish; Katiyar, Akshay; Madhupriya; Rao, G P

    2016-06-01

    Symptoms of little leaf, leaf chlorosis and leaf malformations with mosaic mottling symptoms were observed in two brinjal varieties (Pusa Shyamla and Pusa Purple Cluster) in fields of IARI, New Delhi, India during 2014-2015. Electron microscopy, PCR and sequence analysis first time provided evidence of association of Candidatus Phytoplasma trifolii with potato virus X and potato virus Y in brinjal in India.

  9. Transcriptomics of the interaction between the monopartite phloem-limited geminivirus tomato yellow leaf curl Sardinia virus and Solanum lycopersicum highlights a role for plant hormones, autophagy and plant immune system fine tuning during infection.

    PubMed

    Miozzi, Laura; Napoli, Chiara; Sardo, Luca; Accotto, Gian Paolo

    2014-01-01

    Tomato yellow leaf curl Sardinia virus (TYLCSV), a DNA virus belonging to the genus Begomovirus, causes severe losses in tomato crops. It infects only a limited number of cells in the vascular tissues, making difficult to detect changes in host gene expression linked to its presence. Here we present the first microarray study of transcriptional changes induced by the phloem-limited geminivirus TYLCSV infecting tomato, its natural host. The analysis was performed on the midrib of mature leaves, a material naturally enriched in vascular tissues. A total of 2206 genes were up-regulated and 1398 were down-regulated in infected plants, with an overrepresentation of genes involved in hormone metabolism and responses, nucleic acid metabolism, regulation of transcription, ubiquitin-proteasome pathway and autophagy among those up-regulated, and in primary and secondary metabolism, phosphorylation, transcription and methylation-dependent chromatin silencing among those down-regulated. Our analysis showed a series of responses, such as the induction of GA- and ABA-responsive genes, the activation of the autophagic process and the fine tuning of the plant immune system, observed only in TYLCSV-tomato compatible interaction so far. On the other hand, comparisons with transcriptional changes observed in other geminivirus-plant interactions highlighted common host responses consisting in the deregulation of biotic stress responsive genes, key enzymes in the ethylene biosynthesis and methylation cycle, components of the ubiquitin proteasome system and DNA polymerases II. The involvement of conserved miRNAs and of solanaceous- and tomato-specific miRNAs in geminivirus infection, investigated by integrating differential gene expression data with miRNA targeting data, is discussed.

  10. Molecular diagnosis of Papaya meleira virus (PMeV) from leaf samples of Carica papaya L. using conventional and real-time RT-PCR.

    PubMed

    Abreu, Paolla M V; Piccin, João G; Rodrigues, Silas P; Buss, David S; Ventura, José A; Fernandes, Patricia M B

    2012-03-01

    Papaya meleira virus (PMeV) is the causal agent of papaya sticky disease. This study describes two methods for molecular diagnosis of PMeV using conventional and real-time PCR. These methods were shown to be more efficient than current methods of viral detection using extraction of PMeV dsRNA and observation of symptoms in the field. The methods described here were used to evaluate the effect of inoculation of papaya plants with purified PMeV dsRNA on the progress of PMeV infection. A single inoculation with PMeV dsRNA was observed to delay the progress of the virus infection by several weeks. The possibility of vertical transmission of PMeV was also investigated. No evidence was found for PMeV transmission through seeds collected from diseased fruit. The implications of these results for the epidemiology of PMeV and the management of papaya sticky disease are discussed.

  11. Label-free Proteomic Reveals that Cowpea Severe Mosaic Virus Transiently Suppresses the Host Leaf Protein Accumulation During the Compatible Interaction with Cowpea (Vigna unguiculata [L.] Walp.).

    PubMed

    Paiva, Ana L S; Oliveira, Jose T A; de Souza, Gustavo A; Vasconcelos, Ilka M

    2016-12-02

    Viruses are important plant pathogens that threaten diverse crops worldwide. Diseases caused by Cowpea severe mosaic virus (CPSMV) have drawn attention because of the serious damages they cause to economically important crops including cowpea. This work was undertaken to quantify and identify the responsive proteins of a susceptible cowpea genotype infected with CPSMV, in comparison with mock-inoculated controls, using label-free quantitative proteomics and databanks, aiming at providing insights on the molecular basis of this compatible interaction. Cowpea leaves were mock- or CPSMV-inoculated and 2 and 6 days later proteins were extracted and analyzed. More than 3000 proteins were identified (data available via ProteomeXchange, identifier PXD005025) and 75 and 55 of them differentially accumulated in response to CPSMV, at 2 and 6 DAI, respectively. At 2 DAI, 76% of the proteins decreased in amount and 24% increased. However, at 6 DAI, 100% of the identified proteins increased. Thus, CPSMV transiently suppresses the synthesis of proteins involved particularly in the redox homeostasis, protein synthesis, defense, stress, RNA/DNA metabolism, signaling, and other functions, allowing viral invasion and spread in cowpea tissues.

  12. Video Analysis of Rolling Cylinders

    ERIC Educational Resources Information Center

    Phommarach, S.; Wattanakasiwich, P.; Johnston, I.

    2012-01-01

    In this work, we studied the rolling motion of solid and hollow cylinders down an inclined plane at different angles. The motions were captured on video at 300 frames s[superscript -1], and the videos were analyzed frame by frame using video analysis software. Data from the real motion were compared with the theory of rolling down an inclined…

  13. Critical rolling angle of microparticles

    NASA Astrophysics Data System (ADS)

    Farzi, Bahman; Vallabh, Chaitanya K. P.; Stephens, James D.; Cetinkaya, Cetin

    2016-03-01

    At the micrometer-scale and below, particle adhesion becomes particularly relevant as van der Waals force often dominates volume and surface proportional forces. The rolling resistance of microparticles and their critical rolling angles prior to the initiation of free-rolling and/or complete detachment are critical in numerous industrial processes and natural phenomenon involving particle adhesion and granular dynamics. The current work describes a non-contact measurement approach for determining the critical rolling angle of a single microparticle under the influence of a contact-point base-excitation generated by a transient displacement field of a prescribed surface acoustic wave pulse and reports the critical rolling angle data for a set of polystyrene latex microparticles.

  14. Mechanism of regulation of tomato TRN1 gene expression in late infection with tomato leaf curl New Delhi virus (ToLCNDV).

    PubMed

    Mandal, Arunava; Sarkar, Deepti; Kundu, Surekha; Kundu, Pallob

    2015-12-01

    Tomato leaf curl disease caused by geminiviruses is manifested by curling and puckering of leaves and thickening of veins, resembling developmental defects. This is probably due to the long-term altered regulation of expression of development related gene(s). Our results show that in the infected leaves the transcript level of TORNADO1 (SlTRN1), a gene important for cell expansion and vein formation, increased significantly. SlTRN1 is transcribed from two start sites. The preferential usage of one start site governs its expression in viral-stressed plants. To investigate the role of specific promoter elements in mediating differential expression of SlTRN1, we performed SlTRN1 promoter analysis. The promoter-regulatory sequences harbor multiple W-boxes. The SlWRKY16 transcription factor actively interacts with one of the W-boxes. WRKY proteins are commonly induced by salicylic acid (SA), and consequently SA treatment increased transcript level of SlWRKY16 and SlTRN1. Further mutational analyses confirmed the role of W-boxes in mediating SlTRN1 induction during ToLCNDV infection or SA treatment. We postulate that the activation of SA pathway during stress-response in tomato induces WRKY16, which in turn modulates transcription of SlTRN1 gene. This study unravels the mechanism of regulation of a developmental gene during stress-response, which may affect the severity of symptoms.

  15. Genetic variability of Cotton leaf curl betasatellite in Northern India

    PubMed Central

    Sohrab, Sayed Sartaj; Azhar, Esam I.; Kamal, Mohammad A.; Bhattacharya, P.S.; Rana, D.

    2014-01-01

    Cotton is an important crop and its production is affected by various disease pathogens. Monopartite begomovirus associated betasatellites cause Cotton leaf curl disease (CLCuD) in Northern India. In order to access the occurrence and genetic variability of Cotton leaf curl betasatellites, an extensive field survey was conducted in states of Rajasthan, Punjab and Haryana. We selected the betasatellite sequence for analysis as they are reported as important for disease severity and sequence variability. Based on the field observations, the disease incidence ranged from 30% to 80% during the survey. Full genome and DNA β were amplified from various samples while no amplicon was obtained in some samples. The nucleotide sequence homology ranged from 90.0% to 98.7% with Cotton leaf curl virus (CLCuV), 55.2–55.5% with Bhendi yellow vein mosaic virus, 55.8% with Okra leaf curl virus and 51.70% with Tomato leaf curl virus isolates. The lowest similarity (47.8%) was found in CLCuV-Sudan isolate. Phylogenetic analysis showed that analyzed isolates formed a close cluster with various CLCuV isolates reported earlier. The analysis results show sequence variation in Cotton leaf curl betasatellite which could be the result of recombination. The results obtained by genome amplification and sequence variability indicate that some new variants are circulating and causing leaf curl disease in Rajasthan, Punjab and Haryana. PMID:25473373

  16. Genetic variability of Cotton leaf curl betasatellite in Northern India.

    PubMed

    Sohrab, Sayed Sartaj; Azhar, Esam I; Kamal, Mohammad A; Bhattacharya, P S; Rana, D

    2014-12-01

    Cotton is an important crop and its production is affected by various disease pathogens. Monopartite begomovirus associated betasatellites cause Cotton leaf curl disease (CLCuD) in Northern India. In order to access the occurrence and genetic variability of Cotton leaf curl betasatellites, an extensive field survey was conducted in states of Rajasthan, Punjab and Haryana. We selected the betasatellite sequence for analysis as they are reported as important for disease severity and sequence variability. Based on the field observations, the disease incidence ranged from 30% to 80% during the survey. Full genome and DNA β were amplified from various samples while no amplicon was obtained in some samples. The nucleotide sequence homology ranged from 90.0% to 98.7% with Cotton leaf curl virus (CLCuV), 55.2-55.5% with Bhendi yellow vein mosaic virus, 55.8% with Okra leaf curl virus and 51.70% with Tomato leaf curl virus isolates. The lowest similarity (47.8%) was found in CLCuV-Sudan isolate. Phylogenetic analysis showed that analyzed isolates formed a close cluster with various CLCuV isolates reported earlier. The analysis results show sequence variation in Cotton leaf curl betasatellite which could be the result of recombination. The results obtained by genome amplification and sequence variability indicate that some new variants are circulating and causing leaf curl disease in Rajasthan, Punjab and Haryana.

  17. Leaf curl diseases of two solanaceous species in Southwest Arabia are caused by a monopartite begomovirus evolutionarily most closely related to a species from the Nile Basin and unique suite of betasatellites.

    PubMed

    Idris, Ali M; Abdullah, N M; Brown, J K

    2012-10-01

    The complete genome of 2780 bases was amplified using rolling circle amplification, and cloned, and sequenced for two distinct strains of the monopartite begomovirus Tomato leaf curl Sudan virus (ToLCSDV). The two strains shared 86-91% identity with the previously described ToLCSDV from the Nile Basin, and 90-91% identity with one another. One strain was cloned from symptomatic tomato plants from Tihamah (ToLCSDV-YE[YE:Tih:05]) while the other was cloned from symptomatic tobacco plants collected from Wadi Hadramaut (ToLCSDV-YE[YE:Had:89]). A distinct full-length betasatellite molecule (1352 bases) was cloned from the respective field-infected tomato and tobacco plants. Agro-inoculation of tomato and Nicotiana benthamiana plants with cloned partial tandem repeats of ToLCSDV-YE[YE:Tih11:05]) and the associated betasatellite, Tomato leaf curl Yemen betasatellite (ToLCYEB-[Tih:tom:137:05]), resulted in the reproduction of leaf curl disease symptoms in test plants like those observed in the field-infected plants. The betasatellite contributed to symptom severity in N. benthamiana test plants when it was co-inoculated with ToLCSDV-YE, compared to the milder symptoms that were observed in tobacco plants infected with the helper virus alone.

  18. A review of the mechanisms and components that determine the transmission efficiency of Tomato yellow leaf curl virus (Geminiviridae; Begomovirus) by its whitefly vector.

    PubMed

    Ghanim, Murad

    2014-06-24

    Begomoviruses are a group of icosahedral single stranded DNA viruses exclusively transmitted by the sweet potato whitefly Bemisia tabaci in a persistent, circulative manner. In this mode of transmission, begomoviruses are acquired by their insect vector as intact virions from the plant phloem, move along the food canal, foregut and esophagus and reach the midgut where they are absorbed into the hemolymph via the filter chamber. The filter chamber is the site where most of the ingested food is filtered, and the first site where the majority of begomoviruses appear to be translocated into the hemolymph via unknown proteins or receptors. Transport from the filter chamber to the hemolymph is aided by a Heat Shock Protein 70. Virus particles not translocated across the filter chamber circulate in the midgut loop but it is not known whether absorption into the hemolymph occurs along this loop. Localization studies have confirmed that begomoviruses are not associated with the hindgut and absorption of virions in this organ is unlikely. In the hemolymph, virions have been shown to interact with a GroEL chaperone produced by the whitefly's endosymbiontic bacteria for ensuring their safe journey to the salivary glands. Virions penetrate the primary salivary glands via unknown proteins or receptors and are transported and secreted outside the whitefly to the plant with salivary secretions. Several recent studies have demonstrated the implications of insect and endosymbiont proteins such as the heat shock protein 70 and the bacterial GroEL protein, in the transmission of begomoviruses by B. tabaci. Additional studies attempting to identify other proteins that aid or interact with begomoviruses along their circulation pathway in the whitefly are reviewed in this paper.

  19. Avoiding the parametric roll

    NASA Astrophysics Data System (ADS)

    Acomi, Nicoleta; Ancuţa, Cristian; Andrei, Cristian; Boştinǎ, Alina; Boştinǎ, Aurel

    2016-12-01

    Ships are mainly built to sail and transport cargo at sea. Environmental conditions and state of the sea are communicated to vessels through periodic weather forecasts. Despite officers being aware of the sea state, their sea time experience is a decisive factor when the vessel encounters severe environmental conditions. Another important factor is the loading condition of the vessel, which triggers different behaviour in similar marine environmental conditions. This paper aims to analyse the behaviour of a port container vessel in severe environmental conditions and to estimate the potential conditions of parametric roll resonance. Octopus software simulation is employed to simulate vessel motions under certain conditions of the sea, with possibility to analyse the behaviour of ships and the impact of high waves on ships due to specific wave encounter situations. The study should be regarded as a supporting tool during the decision making process.

  20. Manufacturing Demonstration Facility: Roll-to-Roll Processing

    SciTech Connect

    Datskos, Panos G; Joshi, Pooran C; List III, Frederick Alyious; Duty, Chad E; Armstrong, Beth L; Ivanov, Ilia N; Jacobs, Christopher B; Graham, David E; Moon, Ji Won

    2015-08-01

    This Manufacturing Demonstration Facility (MDF)e roll-to-roll processing effort described in this report provided an excellent opportunity to investigate a number of advanced manufacturing approaches to achieve a path for low cost devices and sensors. Critical to this effort is the ability to deposit thin films at low temperatures using nanomaterials derived from nanofermentation. The overarching goal of this project was to develop roll-to-roll manufacturing processes of thin film deposition on low-cost flexible substrates for electronics and sensor applications. This project utilized ORNL s unique Pulse Thermal Processing (PTP) technologies coupled with non-vacuum low temperature deposition techniques, ORNL s clean room facility, slot dye coating, drop casting, spin coating, screen printing and several other equipment including a Dimatix ink jet printer and a large-scale Kyocera ink jet printer. The roll-to-roll processing project had three main tasks: 1) develop and demonstrate zinc-Zn based opto-electronic sensors using low cost nanoparticulate structures manufactured in a related MDF Project using nanofermentation techniques, 2) evaluate the use of silver based conductive inks developed by project partner NovaCentrix for electronic device fabrication, and 3) demonstrate a suite of low cost printed sensors developed using non-vacuum deposition techniques which involved the integration of metal and semiconductor layers to establish a diverse sensor platform technology.

  1. Rolling Process Modeling Report: Finite-Element Prediction of Roll Separating Force and Rolling Defects

    SciTech Connect

    Soulami, Ayoub; Lavender, Curt A.; Paxton, Dean M.; Burkes, Douglas

    2014-04-23

    Pacific Northwest National Laboratory (PNNL) has been investigating manufacturing processes for the uranium-10% molybdenum (U-10Mo) alloy plate-type fuel for the U.S. high-performance research reactors. This work supports the Convert Program of the U.S. Department of Energy’s National Nuclear Security Administration (DOE/NNSA) Global Threat Reduction Initiative. This report documents modeling results of PNNL’s efforts to perform finite-element simulations to predict roll separating forces and rolling defects. Simulations were performed using a finite-element model developed using the commercial code LS-Dyna. Simulations of the hot rolling of U-10Mo coupons encapsulated in low-carbon steel have been conducted following two different schedules. Model predictions of the roll-separation force and roll-pack thicknesses at different stages of the rolling process were compared with experimental measurements. This report discusses various attributes of the rolled coupons revealed by the model (e.g., dog-boning and thickness non-uniformity).

  2. Body roll in swimming: a review.

    PubMed

    Psycharakis, Stelios G; Sanders, Ross H

    2010-02-01

    In this article, we present a critical review of the swimming literature on body roll, for the purposes of summarizing and highlighting existing knowledge, identifying the gaps and limitations, and stimulating further research. The main research findings can be summarized as follows: swimmers roll their shoulders significantly more than their hips; swimmers increase hip roll but maintain shoulder roll when fatigued; faster swimmers roll their shoulders less than slower swimmers during a 200-m swim; roll asymmetries, temporal differences in shoulder roll and hip roll, and shoulder roll side dominance exist in front crawl swimming, but there is no evidence to suggest that they affect swimming performance; and buoyancy contributes strongly to generating body roll in front crawl swimming. Based on and stimulated by current knowledge, future research should focus on the following areas: calculation of body roll for female swimmers and for backstroke swimming; differences in body roll between breathing and non-breathing cycles; causes of body roll asymmetries and their relation to motor laterality; body roll analysis across a wide range of velocities and swimming distances; exploration of the association between body roll and the magnitude and direction of propulsive/resistive forces developed during the stroke cycle; and the influence of kicking actions on the generation of body roll.

  3. First report of Persimmon cryptic virus and Persimmon virus A in Korea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2014, a total of 77 persimmon (Diospyros kaki Thunb.) trees from Korean commercial persimmon orchards were surveyed for Persimmon cryptic virus (PeCV) and Persimmon virus A (PeVA). Leaf samples were collected from symptomatic trees with necrosis (two), or mosaic and leaf malformations (one) and 7...

  4. Development of roll-to-roll hot embossing system with induction heater for micro fabrication.

    PubMed

    Yun, Dongwon; Son, Youngsu; Kyung, Jinho; Park, Heechang; Park, Chanhun; Lee, Sunghee; Kim, Byungin

    2012-01-01

    In this paper, a hot embossing heating roll with induction heater inside the roll is proposed. The induction heating coil is installed inside a roll that is used as a heating roll of a roll-to-roll (R2R) hot embossing apparatus. Using an inside installed heating coil gives the roll-to-roll hot embossing system a more even temperature distribution on the surface of the heating roll compared to that of previous systems, which used an electric wire for heating. This internal induction heating roll can keep the working environment much cleaner because there is no oil leakage compared to the oiled heating roll. This paper describes the principles and provides an analysis of this proposed system; some evaluation has also been performed for the system. A real R2R hot embossing heating roll system was fabricated and some experiments on micro-pattering have been performed. After that, evaluation has been performed on the results.

  5. Begomovirus diversity in tomato crops and weeds in Ecuador and the detection of a recombinant isolate of rhynchosia golden mosaic Yucatan virus infecting tomato.

    PubMed

    Paz-Carrasco, Lenin C; Castillo-Urquiza, Gloria P; Lima, Alison T M; Xavier, Cesar A D; Vivas-Vivas, Leticia M; Mizubuti, Eduardo S G; Zerbini, F Murilo

    2014-08-01

    Viral diseases caused by begomoviruses are of economic importance due to their adverse effects on the production of tropical and subtropical crops. In Ecuador, despite reports of significant infestations of Bemisia tabaci in the late 1990s, only very recently has a begomovirus, tomato leaf deformation virus (ToLDeV, also present in Peru), been reported in tomato. ToLDeV is the first monopartite begomovirus discovered that originated in the Americas, and its presence in Ecuador highlights the need for a wider survey of tomato-infecting begomoviruses in this country. Tomato and weed samples were collected in 2010 and 2011 in six provinces of Ecuador, and begomovirus genomes were cloned and sequenced using a rolling-circle-amplification-based approach. Most tomato samples from the provinces of Guayas, Loja, Manabi and Santa Elena were infected with tomato leaf deformation virus (ToLDeV). One sample from Manabi had a triple infection with ToLDeV, rhynchosia golden mosaic Yucatan virus (RhGMYuV) and an isolate that was a recombinant between the two. A new begomovirus was detected in another tomato sample from Manabi. Samples of Rhynchosia sp. from the provinces of Guayas and Manabi were infected by RhGMYuV. These results indicate not only the prevalence of ToLDeV in tomato in Ecuador but also the presence of other viruses, albeit at a much lower frequency.

  6. 75 FR 64254 - Certain Hot-Rolled Flat-Rolled Carbon Quality Steel Products From Brazil; Final Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-19

    ... International Trade Administration Certain Hot-Rolled Flat-Rolled Carbon Quality Steel Products From Brazil... order on certain hot-rolled, flat-rolled carbon quality steel products (hot-rolled steel) from Brazil. See Certain Hot- Rolled Flat-Rolled Carbon Quality Steel Products From Brazil: Preliminary Results...

  7. Fundamental phenomena governing heat transfer during rolling

    NASA Astrophysics Data System (ADS)

    Chen, W. C.; Samarasekera, I. V.; Hawbolt, E. B.

    1993-06-01

    To quantify the effect of roll chilling on the thermal history of a slab during hot rolling, tests were conducted at the Canada Center for Mineral and Energy Technology (CANMET) and at the University of British Columbia (UBC). In these tests, the surface and the interior temperatures of specimens were recorded during rolling using a data acquisition system. The corresponding heat-transfer coefficients in the roll bite were back-calculated by a trial-and-error method using a heat-transfer model. The heat-transfer coefficient was found to increase along the arc of contact and reach a maximum, followed by a decrease, until the exit of the roll bite. Its value was influenced by rolling parameters, such as percent reduction, rolling speed, rolling temperature, material type, etc. It was shown that the heat-transfer coefficient in the roll gap was strongly dependent on the roll pressure, and the effect of different variables on the interfacial heat-transfer coefficient can be related to their influence on pressure. At low mean roll pressure, such as in the case of rolling plain carbon steels at elevated temperature, the maximum heat-transfer coefficient in the roll bite was in the 25 to 35 kW/m2 °C range. As the roll pressure increased with lower rolling temperature and higher deformation resistance of stainless steel and microalloyed grades, the maximum heat-transfer coefficient reached a value of 620 kW/m2 °C. Obviously, the high pressure improved the contact between the roll and the slab surface, thereby reducing the resistance to heat flow. The mean roll-gap heat-transfer coefficient at the interface was shown to be linearly related to mean roll pressure. This finding is important because it permitted a determination of heat-transfer coefficients applicable to industrial rolling from pilot mill data. Thus, the thermal history of a slab during rough rolling was computed using a model in which the mean heat-transfer coefficient between the roll and the slab was

  8. Hot rolling of thick uranium molybdenum alloys

    DOEpatents

    DeMint, Amy L.; Gooch, Jack G.

    2015-11-17

    Disclosed herein are processes for hot rolling billets of uranium that have been alloyed with about ten weight percent molybdenum to produce cold-rollable sheets that are about one hundred mils thick. In certain embodiments, the billets have a thickness of about 7/8 inch or greater. Disclosed processes typically involve a rolling schedule that includes a light rolling pass and at least one medium rolling pass. Processes may also include reheating the rolling stock and using one or more heavy rolling passes, and may include an annealing step.

  9. Improvement of rolling 6 mm thin plates in plate rolling mill PT. Krakatau Posco

    NASA Astrophysics Data System (ADS)

    Pujiyanto, Hamdani

    2017-01-01

    A 6-mm thin plate is difficult to produce especially if the product requires wide size and high strength. Flatness is the main quality issue in rolling 6-mm plate using a 4-high reversing mill which use ±1100-mm work roll. Thus some methods are applied to overcome such issue in order to comply to customer quality requirement. Pre-rolling, rolling, and post-rolling conditions have to be considered comprehensively. Roll unit management will be the key factor before rolling condition. The roll unit itself has a significant impact on work roll crown wearness in relation with work roll intial crown and thermal crown. Work roll crown along with the modification of hydraulic gap control (HGC) could directly alter the flatness of the plate.

  10. Roll-to-Roll Nanoimprint Lithography Simulations for Flexible Substrates

    NASA Astrophysics Data System (ADS)

    Spann, Andrew; Jain, Akhilesh; Bonnecaze, Roger

    2015-11-01

    UV roll-to-roll nanoimprint lithography enables the patterning of features onto a flexible substrate for bendable electronics in a continuous process. One of the most important design goals in this process is to make the residual layer thickness of the photoresist in unpatterned regions as thin and uniform as possible. Another important goal is to minimize the imprint time to maximize throughput. We develop a multi-scale model to simulate the spreading of photoresist drops as the template is pressed against the substrate. We include the effect of capillary pressure on the bending of the substrate and show how this distorts uniformity in the residual thickness layer. Our simulation code is parallelized and can simulate the flow and merging of thousands of drops. We investigate the effect of substrate tension and the initial arrangement of drops on the residual layer thickness and imprint time. We find that for a given volume of photoresist, distributing that volume to more drops initially decreases the imprint time. We conclude with recommendations for scale-up and optimal operations of roll-to-roll nanoimprint lithography systems. The authors acknowledge the Texas Advanced Computing Center at The University of Texas at Austin for providing high performance computing resources.

  11. Climate Ready Estuaries Rolling Easements Primer

    EPA Pesticide Factsheets

    Rolling easements enable wetlands and beaches to migrate inland and allow society to avoid the costs and hazards of protecting low lands from rising sea levels. This document provides a primer on more than a dozen rolling easement approaches.

  12. Identification of extrachromosomal circular DNA in hop via rolling circle amplification

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During a survey looking for viruses affecting hop plants in the Willamette Valley of Oregon, a circular DNA molecule was identified via rolling circle amplification (RCA) and later characterized. The 5.7 kb long molecule only matched in a minor cover to a microsatellite region in the Humulus lupulus...

  13. The rolling-circle melting-pot model for porcine circovirus DNA replication

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A stem-loop structure, formed by a pair of inverted repeats during DNA replication, is a conserved feature at the origin of DNA replication (Ori) among plant and animal viruses, bacteriophages and plasmids that replicate their genomes via the rolling-circle replication (RCR) mechanism. Porcine circo...

  14. One-zone rolling of composite materials

    NASA Astrophysics Data System (ADS)

    Kokhan, L. S.; Morozov, Yu. A.; Slavgorodskaya, Yu. B.

    2016-12-01

    The energy-force parameters of free rolling of a strip without its tension and rolling with one backward or forward creep zone in the deformation zone are compared. The limiting backward or forward tensions are determined, and the change in the linear sizes of a composite billet during deformation in a rolling mill is considered.

  15. Rolling Tachyon in Nonlocal Cosmology

    SciTech Connect

    Joukovskaya, L.

    2007-11-20

    Nonlocal cosmological models derived from String Field Theory are considered. A new method for constructing rolling tachyon solutions in the FRW metric in two field configuration is proposed and solutions of the Friedman equations with nonlocal operator are presented. The cosmological properties of these solutions are discussed.

  16. Virus Strains Causing Mosaic in Louisiana and Florida Sugarcane

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mosaic caused by Sugarcane mosaic virus (SCMV) and Sorghum mosaic virus (SrMV), respectively, affects sugarcane in Louisiana and Florida. Between 2004 and 2007, surveys were conducted in both states to determine which virus and virus strains were causing mosaic of sugarcane. In Louisiana, leaf sam...

  17. The Discovery of Rolling Circle Amplification and Rolling Circle Transcription.

    PubMed

    Mohsen, Michael G; Kool, Eric T

    2016-11-15

    Nucleic acid amplification is a hugely important technology for biology and medicine. While the polymerase chain reaction (PCR) has been highly useful and effective, its reliance on heating and cooling cycles places some constraints on its utility. For example, the heating step of PCR can destroy biological molecules under investigation and heat/cool cycles are not applicable in living systems. Thus, isothermal approaches to DNA and RNA amplification are under widespread study. Perhaps the simplest of these are the rolling circle approaches, including rolling circle amplification (RCA) and rolling circle transcription (RCT). In this strategy, a very small circular oligonucleotide (e.g., 25-100 nucleotides in length) acts as a template for a DNA or an RNA polymerase, producing long repeating product strands that serve as amplified copies of the circle sequence. Here we describe the early developments and studies involving circular oligonucleotides that ultimately led to the burgeoning rolling circle technologies currently under development. This Account starts with our studies on the design of circular oligonucleotides as novel DNA- and RNA-binding motifs. We describe how we developed chemical and biochemical strategies for synthesis of well-defined circular oligonucleotides having defined sequence and open (unpaired) structure, and we outline the unusual ways in which circular DNAs can interact with other nucleic acids. We proceed next to the discovery of DNA and RNA polymerase activity on these very small cyclic DNAs. DNA polymerase "rolling circle" activities were discovered concurrently in our laboratory and that of Andrew Fire. We describe the surprising efficiency of this process even on shockingly small circular DNAs, producing repeating DNAs thousands of nucleotides in length. RNA polymerase activity on circular oligonucleotides was first documented in our group in 1995; especially surprising in this case was the finding that the process occurs efficiently

  18. 76 FR 34101 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-10

    ... COMMISSION Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia Determinations... U.S.C. 1675(c)), that termination of the suspension agreement on hot- rolled flat-rolled carbon... determines that revocation of the countervailing duty order on hot-rolled flat-rolled carbon-quality...

  19. 75 FR 16504 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-01

    ... COMMISSION Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia AGENCY: United... countervailing duty order on certain hot-rolled flat-rolled carbon-quality steel products (``hot-rolled steel'') from Brazil, the antidumping duty orders on hot-rolled steel from Brazil and Japan, and the...

  20. 76 FR 22868 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil: Final Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-25

    ... International Trade Administration Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil... certain hot-rolled flat-rolled carbon- quality steel products (HRS) from Brazil for the period January 1...: Background Since the issuance of Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From...

  1. 75 FR 42782 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-22

    ... COMMISSION Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia AGENCY: United...-year reviews concerning the countervailing duty order on certain hot-rolled flat-rolled carbon-quality steel products (``hot-rolled steel'') from Brazil, the antidumping duty orders on hot-rolled steel...

  2. 75 FR 62566 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-12

    ... COMMISSION Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia AGENCY: United... countervailing duty order on hot-rolled flat-rolled carbon-quality steel products (``hot-rolled steel'') from Brazil, the antidumping duty orders on hot-rolled steel from Brazil and Japan, and the...

  3. 75 FR 47263 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From the Russian Federation; Final...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-05

    ... International Trade Administration Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From the Russian... expedited sunset review of the antidumping duty suspended investigation on certain hot-rolled flat-rolled... antidumping duty investigation of certain hot-rolled flat- rolled carbon-quality steel products...

  4. 75 FR 65453 - Certain Hot-Rolled Flat-Rolled Carbon Quality Steel Flat Products From Brazil: Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-25

    ... International Trade Administration Certain Hot-Rolled Flat-Rolled Carbon Quality Steel Flat Products From Brazil... duty order on certain hot-rolled flat-rolled carbon quality steel flat products (hot-rolled steel) from Brazil. The review covers four producers/exporters of hot-rolled steel from Brazil, all...

  5. A rolling 3-UPU parallel mechanism

    NASA Astrophysics Data System (ADS)

    Miao, Zhihuai; Yao, Yan'an; Kong, Xianwen

    2013-12-01

    A novel rolling mechanism is proposed based on a 3-UPU parallel mechanism in this paper. The rolling mechanism is composed of two platforms connected by three UPU (universal-prismatic-universal) serial-chain type limbs. The degree-of-freedom of the mechanism is analyzed using screw theory. Gait analysis and stability analysis are presented in detail. Four rolling modes of the mechanism are discussed and simulated. The feasibility of the rolling mechanism is verified by means of a physical prototype. Finally, its terrain adaptability is enhanced through planning the rolling gaits.

  6. Elimination of five sugarcane viruses from sugarcane using in vitro culture of axillary bud and apical meristem

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Procedures were developed for the in vitro elimination of Sugarcane mosaic virus (SCMV), Sorghum mosaic virus (SrMV), Sugarcane streak mosaic virus (SCSMV), Sugarcane yellow leaf virus (SCYLV) and Fiji disease virus (FDV) from infected sugarcane. In vitro shoot regeneration, elongation and virus el...

  7. Roll Casting of Al-25%Si

    SciTech Connect

    Haga, Toshio; Harada, Hideto; Watari, Hisaki

    2011-05-04

    Strip casting of Al-25%Si strip was tried using an unequal diameter twin roll caster. The diameter of the lower roll (large roll) was 1000 mm and the diameter of the upper roll (small roll) was 250 mm. Roll material was mild steel. The sound strip could be cast at the speeds ranging from 8 m/min to 12 m/min. The strip did not stick to the roll without the parting material. The primary Si, which existed at centre area of the thickness direction, was larger than that which existed at other area. The size of the primary Si was smaller than 0.2 mm. Eutectic Si was smaller 5 {mu}m. The as-cast strip was ranging from 2 mm to 3 mm thick and its width was 100 mm. The as-cast strip could be hot rolled down to 1 mm. The hot rolled strip was cold rolled. The primary Si became smaller and the pore occurred around the primary Si after the rolling.

  8. Towards roll-to-roll manufacturing of polymer photonic devices

    NASA Astrophysics Data System (ADS)

    Subbaraman, Harish; Lin, Xiaohui; Ling, Tao; Guo, L. Jay; Chen, Ray T.

    2014-03-01

    Traditionally, polymer photonic devices are fabricated using clean-room processes such as photolithography, e-beam lithography, reactive ion etching (RIE) and lift-off methods etc, which leads to long fabrication time, low throughput and high cost. We have utilized a novel process for fabricating polymer photonic devices using a combination of imprinting and ink jet printing methods, which provides high throughput on a variety of rigid and flexible substrates with low cost. We discuss the manufacturing challenges that need to be overcome in order to realize true implementation of roll-to-roll manufacturing of flexible polymer photonic systems. Several metrology and instrumentation challenges involved such as availability of particulate-free high quality substrate, development and implementation of high-speed in-line and off-line inspection and diagnostic tools with adaptive control for patterned and unpatterned material films, development of reliable hardware, etc need to be addressed and overcome in order to realize a successful manufacturing process. Due to extreme resolution requirements compared to print media, the burden of software and hardware tools on the throughput also needs to be carefully determined. Moreover, the effect of web wander and variations in web speed need to accurately be determined in the design of the system hardware and software. In this paper, we show the realization of solutions for few challenges, and utilizing these solutions for developing a high-rate R2R dual stage ink-jet printer that can provide alignment accuracy of <10μm at a web speed of 5m/min. The development of a roll-to-roll manufacturing system for polymer photonic systems opens limitless possibilities for the deployment of high performance components in a variety of applications including communication, sensing, medicine, agriculture, energy, lighting etc.

  9. Tomato ringspot virus and Tobacco ringspot virus in Highbush Blueberry in New York State

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A survey of highbush blueberry (Vaccinium corymbosum L.) cultivars Patriot and Bluecrop showing virus-like symptoms and decline in vigor in New York was conducted to assess the occurrence of viruses. Leaf samples from symptomatic and asymptomatic bushes reacted positively to Tobacco ringspot virus ...

  10. Rubber rolling over a sphere

    NASA Astrophysics Data System (ADS)

    Koiller, J.; Ehlers, K.

    2007-04-01

    “Rubber” coated bodies rolling over a surface satisfy a no-twist condition in addition to the no slip condition satisfied by “marble” coated bodies [1]. Rubber rolling has an interesting differential geometric appeal because the geodesic curvatures of the curves on the surfaces at corresponding points are equal. The associated distribution in the 5 dimensional configuration space has 2 3 5 growth (these distributions were first studied by Cartan; he showed that the maximal symmetries occurs for rubber rolling of spheres with 3:1 diameters ratio and materialize the exceptional group G 2). The 2 3 5 nonholonomic geometries are classified in a companion paper [2] via Cartan’s equivalence method [3]. Rubber rolling of a convex body over a sphere defines a generalized Chaplygin system [4 8] with SO(3) symmetry group, total space Q = SO(3) × S 2 and base S 2, that can be reduced to an almost Hamiltonian system in T* S 2 with a non-closed 2-form ωNH. In this paper we present some basic results on the sphere-sphere problem: a dynamically asymmetric but balanced sphere of radius b (unequal moments of inertia I j but with center of gravity at the geometric center), rubber rolling over another sphere of radius a. In this example ωNH is conformally symplectic [9]: the reduced system becomes Hamiltonian after a coordinate dependent change of time. In particular there is an invariant measure, whose density is the determinant of the reduced Legendre transform, to the power p = 1/2( b/a - 1). Using sphero-conical coordinates we verify the result by Borisov and Mamaev [10] that the system is integrable for p = -1/2 (ball over a plane). They have found another integrable case [11] corresponding to p = -3/2 (rolling ball with twice the radius of a fixed internal ball). Strikingly, a different set of sphero-conical coordinates separates the Hamiltonian in this case. No other integrable cases with different I j are known.

  11. QTL analysis of disease resistance to leaf spots and TSWV in peanut (Arachis hypogaea)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Early leaf spot (ELS), caused by Cercospora arachidicola, late leaf spot (LLS), caused by Cercosporidium personatum, and Tomato spotted wilt virus (TSWV) result in great losses in yield in peanut (Arachis hypogaea L.). In order to identify quantitative trait loci (QTL) for resistance to these dise...

  12. Tribological Testing of Anti-Adhesive coatings for Cold Rolling Mill Rolls--Application to TiN-Coated Rolls

    SciTech Connect

    Ould, Choumad; Montmitonnet, Pierre; Gachon, Yves; Badiche, Xavier

    2011-05-04

    Roll life is a major issue in cold strip rolling. Roll wear may result either in too low roll roughness, bringing friction below the minimum requested for strip entrainment; or it may degrade strip surface quality. On the contrary, adhesive wear and transfer (''roll coating'', ''pick up'') may form a thick metallic deposits on the roll which increases friction excessively and degrades strip surface again [1]. The roll surface, with the help of a materials-adapted lubricant, must therefore possess anti-wear and anti-adhesive properties. Thus, High Speed Steeel (HSS) rolls show superior properties compared with standard Cr-steel rolls due to their high carbide surface coverage. Another way to improve wear and adhesion properties of surfaces is to apply hard metallic (hard-Cr) or ceramic coatings. Chromium is renowned for its excellent anti-wear and anti-adhesive properties and may serve as a reference. Here, as a first step towards alternative, optimised coatings, a PVD TiN coating has been deposited on tool steels, as previous attempts have proved TiN to be rather successful in cold rolling experiments [2,3]. Different tribological tests are reported here, giving insight in both anti-adhesive properties and fatigue life improvement.

  13. Diversity, Mutation and Recombination Analysis of Cotton Leaf Curl Geminiviruses.

    PubMed

    Saleem, Huma; Nahid, Nazia; Shakir, Sara; Ijaz, Sehrish; Murtaza, Ghulam; Khan, Asif Ali; Mubin, Muhammad; Nawaz-Ul-Rehman, Muhammad Shah

    2016-01-01

    The spread of cotton leaf curl disease in China, India and Pakistan is a recent phenomenon. Analysis of available sequence data determined that there is a substantial diversity of cotton-infecting geminiviruses in Pakistan. Phylogenetic analyses indicated that recombination between two major groups of viruses, cotton leaf curl Multan virus (CLCuMuV) and cotton leaf curl Kokhran virus (CLCuKoV), led to the emergence of several new viruses. Recombination detection programs and phylogenetic analyses showed that CLCuMuV and CLCuKoV are highly recombinant viruses. Indeed, CLCuKoV appeared to be a major donor virus for the coat protein (CP) gene, while CLCuMuV donated the Rep gene in the majority of recombination events. Using recombination free nucleotide datasets the substitution rates for CP and Rep genes were determined. We inferred similar nucleotide substitution rates for the CLCuMuV-Rep gene (4.96X10-4) and CLCuKoV-CP gene (2.706X10-4), whereas relatively higher substitution rates were observed for CLCuMuV-CP and CLCuKoV-Rep genes. The combination of sequences with equal and relatively low substitution rates, seemed to result in the emergence of viral isolates that caused epidemics in Pakistan and India. Our findings also suggest that CLCuMuV is spreading at an alarming rate, which can potentially be a threat to cotton production in the Indian subcontinent.

  14. Diversity, Mutation and Recombination Analysis of Cotton Leaf Curl Geminiviruses

    PubMed Central

    Saleem, Huma; Nahid, Nazia; Shakir, Sara; Ijaz, Sehrish; Murtaza, Ghulam; Khan, Asif Ali; Mubin, Muhammad; Nawaz-ul-Rehman, Muhammad Shah

    2016-01-01

    The spread of cotton leaf curl disease in China, India and Pakistan is a recent phenomenon. Analysis of available sequence data determined that there is a substantial diversity of cotton-infecting geminiviruses in Pakistan. Phylogenetic analyses indicated that recombination between two major groups of viruses, cotton leaf curl Multan virus (CLCuMuV) and cotton leaf curl Kokhran virus (CLCuKoV), led to the emergence of several new viruses. Recombination detection programs and phylogenetic analyses showed that CLCuMuV and CLCuKoV are highly recombinant viruses. Indeed, CLCuKoV appeared to be a major donor virus for the coat protein (CP) gene, while CLCuMuV donated the Rep gene in the majority of recombination events. Using recombination free nucleotide datasets the substitution rates for CP and Rep genes were determined. We inferred similar nucleotide substitution rates for the CLCuMuV-Rep gene (4.96X10-4) and CLCuKoV-CP gene (2.706X10-4), whereas relatively higher substitution rates were observed for CLCuMuV-CP and CLCuKoV-Rep genes. The combination of sequences with equal and relatively low substitution rates, seemed to result in the emergence of viral isolates that caused epidemics in Pakistan and India. Our findings also suggest that CLCuMuV is spreading at an alarming rate, which can potentially be a threat to cotton production in the Indian subcontinent. PMID:26963635

  15. Leaf growth is conformal

    NASA Astrophysics Data System (ADS)

    Alim, Karen; Armon, Shahaf; Shraiman, Boris I.; Boudaoud, Arezki

    2016-10-01

    Growth pattern dynamics lie at the heart of morphogenesis. Here, we investigate the growth of plant leaves. We compute the conformal transformation that maps the contour of a leaf at a given stage onto the contour of the same leaf at a later stage. Based on the mapping we predict the local displacement field in the leaf blade and find it to agree with the experimentally measured displacement field to 92%. This approach is applicable to any two-dimensional system with locally isotropic growth, enabling the deduction of the whole growth field just from observation of the tissue contour.

  16. Rolling-Friction Robotic Gripper

    NASA Technical Reports Server (NTRS)

    Vranish, John M.

    1992-01-01

    Robotic gripper using rolling-friction fingers closes in on object with interface designed to mate with rollers somewhat misaligned initially, aligns object with respect to itself, then holds object securely in uniquely determined position and orientation. Operation of gripper causes minimal wear and burring of gripper and object. Exerts minimal friction forces on object when grasping and releasing. Releases object easily and reliably even when side forces and torques are between itself and object.

  17. Rolling Mill Hill, Nashville, TN

    EPA Pesticide Factsheets

    Rolling Mill Hill was the home to Nashville General Hospital from 1890 to the 1990s and encompassed several buildings and structures. These existing buildings of historical significance were re-used in the form of apartments. The original Trolley Barns on the site are now artists’ lofts and are home to several companies and non-profit offices. Nance Place, which entails additional buildings built on-site, is a Tax Credit Workforce Housing Development and is Platinum LEED certified.

  18. Roll formed pan solar module

    SciTech Connect

    Jester, T.L.; Bottenberg, W.R.; Gay, C.F.; Yerkes, J.W.

    1984-02-21

    A solar module comprising a solar cell string laminated between layers of pottant material and a transparent superstrate and a steel substrate. The steel substrate is roll formed to provide stiffening flanges on its edges while simultaneously forming a pan-shaped structure to hold other portions of the laminate in position during the laminating process. An improved terminal provides high voltage protection and improved mechanical strength. A conduit element provides protected raceways for external wires connected to module terminals.

  19. Rolling Contact Fatigue of Ceramics

    SciTech Connect

    Wereszczak, Andrew A; Wang, W.; Wang, Y.; Hadfield, M.; Kanematsu, W.; Kirkland, Timothy Philip; Jadaan, Osama M.

    2006-09-01

    High hardness, low coefficient of thermal expansion and high temperature capability are properties also suited to rolling element materials. Silicon nitride (Si{sub 3}N{sub 4}) has been found to have a good combination of properties suitable for these applications. However, much is still not known about rolling contact fatigue (RCF) behavior, which is fundamental information to assess the lifetime of the material. Additionally, there are several test techniques that are employed internationally whose measured RCF performances are often irreconcilable. Due to the lack of such information, some concern for the reliability of ceramic bearings still remains. This report surveys a variety of topics pertaining to RCF. Surface defects (cracks) in Si{sub 3}N{sub 4} and their propagation during RCF are discussed. Five methods to measure RCF are then briefly overviewed. Spalling, delamination, and rolling contact wear are discussed. Lastly, methods to destructively (e.g., C-sphere flexure strength testing) and non-destructively identify potential RCF-limiting flaws in Si{sub 3}N{sub 4} balls are described.

  20. A Semianalytic Model of Leukocyte Rolling

    PubMed Central

    Krasik, Ellen F.; Hammer, Daniel A.

    2004-01-01

    Rolling allows leukocytes to maintain adhesion to vascular endothelium and to molecularly coated surfaces in flow chambers. Using insights from adhesive dynamics, a computational method for simulating leukocyte rolling and firm adhesion, we have developed a semianalytic model for the steady-state rolling of a leukocyte. After formation in a force-free region of the contact zone, receptor-ligand bonds are transported into the trailing edge of the contact zone. Rolling velocity results from a balance of the convective flux of bonds and the rate of dissociation at the back edge of the contact zone. We compare the model's results to that of adhesive dynamics and to experimental data on the rolling of leukocytes, with good agreement. We calculate the dependence of rolling velocity on shear rate, intrinsic forward and reverse reaction rates, bond stiffness, and reactive compliance, and use the model to calculate a state diagram relating molecular parameters and the dynamic state of adhesion. A dimensionless form of the analytic model permits exploration of the parameters that control rolling. The chemical affinity of a receptor-ligand pair does not uniquely determine rolling velocity. We elucidate a fundamental relationship between off-rate, ligand density, and reactive compliance at the transition between firm and rolling adhesion. The model provides a rapid method for screening system parameters for the potential to mediate rolling. PMID:15315955

  1. Project LEAF Documents

    EPA Pesticide Factsheets

    Project LEAF has a goal of educating farmworkers about how to reduce pesticide exposure to their families from pesticide residues they may be inadvertently taking home on their clothing, etc. Find outreach materials.

  2. Deer predation on leaf miners via leaf abscission

    NASA Astrophysics Data System (ADS)

    Yamazaki, Kazuo; Sugiura, Shinji

    2008-03-01

    The evergreen oak Quercus gilva Blume sheds leaves containing mines of the leaf miner Stigmella sp. (Lepidoptera: Nepticulidae) earlier than leaves with no mines in early spring in Nara, central Japan. The eclosion rates of the leaf miner in abscised and retained leaves were compared in the laboratory to clarify the effects of leaf abscission on leaf miner survival in the absence of deer. The leaf miner eclosed successfully from both fallen leaves and leaves retained on trees. However, sika deer ( Cervus nippon centralis Kishida) feed on the fallen mined leaves. Field observations showed that deer consume many fallen leaves under Q. gilva trees, suggesting considerable mortality of leaf miners due to deer predation via leaf abscission. This is a previously unreported relationship between a leaf miner and a mammalian herbivore via leaf abscission.

  3. Deer predation on leaf miners via leaf abscission.

    PubMed

    Yamazaki, Kazuo; Sugiura, Shinji

    2008-03-01

    The evergreen oak Quercus gilva Blume sheds leaves containing mines of the leaf miner Stigmella sp. (Lepidoptera: Nepticulidae) earlier than leaves with no mines in early spring in Nara, central Japan. The eclosion rates of the leaf miner in abscised and retained leaves were compared in the laboratory to clarify the effects of leaf abscission on leaf miner survival in the absence of deer. The leaf miner eclosed successfully from both fallen leaves and leaves retained on trees. However, sika deer (Cervus nippon centralis Kishida) feed on the fallen mined leaves. Field observations showed that deer consume many fallen leaves under Q. gilva trees, suggesting considerable mortality of leaf miners due to deer predation via leaf abscission. This is a previously unreported relationship between a leaf miner and a mammalian herbivore via leaf abscission.

  4. How rolling forecasting facilitates dynamic, agile planning.

    PubMed

    Miller, Debra; Allen, Michael; Schnittger, Stephanie; Hackman, Theresa

    2013-11-01

    Rolling forecasting may be used to replace or supplement the annual budget process. The rolling forecast typically builds on the organization's strategic financial plan, focusing on the first three years of plan projections and comparing the strategic financial plan assumptions with the organization's expected trajectory. Leaders can then identify and respond to gaps between the rolling forecast and the strategic financial plan on an ongoing basis.

  5. METHOD OF HOT ROLLING URANIUM METAL

    DOEpatents

    Kaufmann, A.R.

    1959-03-10

    A method is given for quickly and efficiently hot rolling uranium metal in the upper part of the alpha phase temperature region to obtain sound bars and sheets possessing a good surface finish. The uranium metal billet is heated to a temperature in the range of 1000 deg F to 1220 deg F by immersion iii a molten lead bath. The heated billet is then passed through the rolls. The temperature is restored to the desired range between successive passes through the rolls, and the rolls are turned down approximately 0.050 inch between successive passes.

  6. Spray Rolling Aluminum Strip for Transportation Applications

    SciTech Connect

    Kevin M. McHugh; Y. Lin; Y. Zhou; E. J. Lavernia; J.-P. Delplanque; S. B. Johnson

    2005-02-01

    Spray rolling is a novel strip casting technology in which molten aluminum alloy is atomized and deposited into the roll gap of mill rolls to produce aluminum strip. A combined experimental/modeling approach has been followed in developing this technology with active participation from industry. The feasibility of this technology has been demonstrated at the laboratory scale and it is currently being scaled-up. This paper provides an overview of the process and compares the microstructure and properties of spray-rolled 2124 aluminum alloy with commercial ingot-processed material

  7. Effect of temper rolling on final shape defects in a V-section roll forming process

    NASA Astrophysics Data System (ADS)

    Abvabi, Akbar; Rolfe, Bernard; Hodgson, Peter D.; Weiss, Matthias

    2013-12-01

    Roll forming is a continuous process in which a flat strip is shaped to the desired profile by sequential bending in a series of roll stands. Because of the large variety of applications of roll forming in the industry, Finite Element Analysis (FEA) is increasingly utilized for roll forming process design. Bending is the dominant deformation mode in roll forming. Sheet materials used in this process are generally temper rolled, roller- or tension- leveled. These processes introduce residual stresses into the material, and recent studies have shown that those affect the material behavior in bending. In this study a numerical model of the temper rolling (skin passing) process was used to determine a residual stress distribution in a dual phase, DP780, steel strip. A 5-stand roll forming process for the forming of a V-section was modeled, and the effect of various thickness reduction levels in the temper rolling process on the final shape defects was analyzed. The results show that a small thickness reduction in the temper rolling process decreases the maximum bow height but the final springback angle increases. It is also shown that reasonable model accuracy can be achieved by including the residual stress information due to temper rolling as initial condition in the numerical modeling of a roll forming process.

  8. Rolling-cuff flexible bellows

    DOEpatents

    Lambert, D.R.

    1982-09-27

    A flexible connector apparatus used to join two stiff non-deformable members, such as piping, is described. The apparatus is provided with one or more flexible sections or assemblies each utilizing a bellows of a rolling cuff type connected between two ridge members, with the bellows being supported by a back-up ring, such that only the curved end sections of the bellows are unsupported. Thus, the bellows can be considered as being of a tube-shaped configuration and thus have high pressure resistance. The components of the flexible apparatus are sealed or welded one to another such that it is fluid tight.

  9. Cytological modifications in maize plants infected by barley yellow dwarf virus and maize dwarf mosaic virus.

    PubMed

    Musetti, R; Bruni, L; Favali, M A

    2002-01-01

    Three inbred lines of maize (33-16, MO17 and B73) differing in their susceptibility to Barley yellow dwarf virus and Maize dwarf mosaic virus were studied to compare the ultrastructural modifications induced by the two viruses in leaf tissues of different age. The results demonstrate that the alterations induced by the two viruses in the different maize lines could depend on the particular line tested.

  10. 75 FR 19369 - Certain Hot-Rolled Flat-Rolled Carbon Quality Steel Products from Brazil: Preliminary Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-14

    ... International Trade Administration Certain Hot-Rolled Flat-Rolled Carbon Quality Steel Products from Brazil... conducting an administrative review of the antidumping duty order on certain hot-rolled flat-rolled carbon quality steel products (hot-rolled steel) from Brazil. The review covers Usinas Siderurgicas de...

  11. 75 FR 43931 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products from Brazil: Preliminary Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-27

    ... International Trade Administration Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products from Brazil... a sunset review of the countervailing duty (``CVD'') order on certain hot-rolled flat-rolled carbon... Department initiated the second sunset review of the countervailing duty order on hot-rolled...

  12. 77 FR 32513 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From the Russian Federation; Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-01

    ... International Trade Administration Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From the Russian... of the Administrative Review of the Suspension Agreement on Hot-Rolled Flat-Rolled Carbon-Quality... administrative review of the Agreement Suspending the Antidumping Duty Investigation of Hot-Rolled...

  13. Damped leaf flexure hinge

    NASA Astrophysics Data System (ADS)

    Chen, Zhong; Chen, Guisheng; Zhang, Xianmin

    2015-05-01

    Flexure-based mechanism like compliant actuation system embeds complex dynamics that will reduce the control bandwidth and limits their dynamic positioning precision. This paper presents a theoretical model of a leaf flexure hinge with damping layers using strain energy method and Kelvin damping model. The modified loss factor of the damped leaf flexure hinge is derived, and the equivalent viscous damping coefficient of the damped leaf hinge is obtained, which could be used to improve the pseudo-rigid-model. The free vibration signals of the hinge in three different damping configurations are measured. The experimental modal analysis also is performed on the three kinds of damped leaf flexure hinges in order to evaluate their 1st order bending natural frequency and vibration-suppressing effects. The evaluation of modified loss factor model also is performed. The experimental results indicate that the constrained layer damping can enhance the structure damping of the hinge even if only single damping layer each side, the modified loss factor model can get good predicts of a damped leaf flexure hinge in the frequency range below 1st order natural frequency, and it is necessary that the dimensional parameters of the damping layers and basic layer of the hinge should be optimized for simplification at the mechanism's design stage.

  14. 76 FR 62894 - Following Procedures When Going Between Rolling Equipment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-11

    ... Federal Railroad Administration Following Procedures When Going Between Rolling Equipment AGENCY: Federal... of following procedures when going ] between rolling equipment. This safety advisory contains various... who, in the course of their work, place themselves between rolling equipment. The railroad...

  15. Spatial and temporal diversity of begomoviral complexes in papayas with leaf curl disease.

    PubMed

    Singh-Pant, P; Pant, P; Mukherjee, S K; Mazumdar-Leighton, S

    2012-07-01

    Old World, monopartite begomoviruses associated with satellite DNA β were observed in papaya showing symptoms of leaf curl disease sampled randomly over five years from within a radius of 250 km in north-central India. Three groups of DNA A sequences were evident. One group resembled chili leaf curl virus infecting tomatoes (ChiLCuV). Another group resembled tomato leaf curl New Delhi virus (ToLCuNDV). The third group was novel (tentatively named papaya leaf crumple virus, PaLCrV), with less than 89% identity to known begomovirus sequences in the GenBank database. At least seven DNA A sequences were putative recombinants. The AC4-encoding regions exhibited highest numbers of non-synonymous substitutions. Most DNA β sequences resembled tomato leaf curl virus-associated DNA βs. A few DNA β sequences were similar to that of croton yellow vein mosaic virus-associated DNA β (CroYVMVβ). One DNA β sequence was novel and showed <65% similarity to its counterparts. Mixed infections and sequence diversity among 25 cloned av1 genes indicated that papayas grown in plantations, kitchen gardens and feral patches in the region are vulnerable to disease outbreak. No geographic or temporal patterns were discernable in the distribution of these viruses.

  16. Rolling Friction on a Wheeled Laboratory Cart

    DTIC Science & Technology

    2012-01-01

    by gravity, and a vehicle (such as a car or bicycle ) accelerating along a level road is driven by a motor or by pedalling. In such cases, static...continuously roll. Consider a cart of mass m that is free rolling up an incline, as sketched in figure 1. The total frictional force f on the cart

  17. School Roll Forecasting Methods: A Review.

    ERIC Educational Resources Information Center

    Simpson, Stephen

    1987-01-01

    A review of the literature concerning local school roll forecasting describes the theoretical model common to most local education agency (LEA) forecasts, identifies a variety of issues relevant to this area of LEA planning, and suggests some opportunities for improvement in LEA school roll forecasting. (Author/CB)

  18. 33 CFR 159.107 - Rolling test.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Rolling test. 159.107 Section 159.107 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION MARINE SANITATION DEVICES Design, Construction, and Testing § 159.107 Rolling test. (a) The device,...

  19. Numerical analysis of Swiss roll metamaterials.

    PubMed

    Demetriadou, A; Pendry, J B

    2009-08-12

    A Swiss roll metamaterial is a resonant magnetic medium, with a negative magnetic permeability for a range of frequencies, due to its self-inductance and self-capacitance components. In this paper, we discuss the band structure, S-parameters and effective electromagnetic parameters of Swiss roll metamaterials, with both analytical and numerical results, which show an exceptional convergence.

  20. Rolling maneuver load alleviation using active controls

    NASA Technical Reports Server (NTRS)

    Woods-Vedeler, Jessica A.; Pototzky, Anthony S.

    1992-01-01

    Rolling Maneuver Load Alleviation (RMLA) was demonstrated on the Active Flexible Wing (AFW) wind tunnel model in the LaRC Transonic Dynamics Tunnel. The design objective was to develop a systematic approach for developing active control laws to alleviate wing incremental loads during roll maneuvers. Using linear load models for the AFW wind-tunnel model which were based on experimental measurements, two RMLA control laws were developed based on a single-degree-of-freedom roll model. The RMLA control laws utilized actuation of outboard control surface pairs to counteract incremental loads generated during rolling maneuvers and roll performance. To evaluate the RMLA control laws, roll maneuvers were performed in the wind tunnel at dynamic pressures of 150, 200, and 250 psf and Mach numbers of .33, .38, and .44, respectively. Loads obtained during these maneuvers were compared to baseline maneuver loads. For both RMLA controllers, the incremental torsion moments were reduced by up to 60 percent at all dynamic pressures and performance times. Results for bending moment load reductions during roll maneuvers varied. In addition, in a multiple function test, RMLA and flutter suppression system control laws were operated simultaneously during roll maneuvers at dynamic pressures 11 percent above the open-loop flutter dynamic pressure.

  1. Roll-forming tubes to header plates

    NASA Technical Reports Server (NTRS)

    Kramer, K.

    1976-01-01

    Technique has been developed for attaching and sealing tubes to header plates using a unique roll-forming tool. Technique is useful for attaching small tubes which are difficult to roll into conventional grooves in header plate tube holes, and for attaching when welding, brazing, or soldering is not desirable.

  2. Lubrication of rolling-element bearings

    NASA Technical Reports Server (NTRS)

    Parker, R. J.

    1980-01-01

    The lubrication of rolling element bearings is surveyed. Emphasis is on the critical design aspects related to speed, temperature, and ambient pressure environment. Types of lubrication including grease, jets, mist, wick, and through the race are discussed. The historical development, present state of technology, and the future problems of rolling element bearing lubrication are discussed.

  3. Occurrence of Apple stem grooving virus in commercial apple seedlings and analysis of its coat protein sequence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Virus infections are responsible for reduced yield and quality in many crops, and are especially problematic in vegetatively-propagated crops such as apple. Three major viruses (Apple stem grooving virus (ASGV), Apple chlorotic leaf spot virus and Apple stem pitting virus) affect apple trees in Kore...

  4. Advances in roll-to-roll imprint lithography for display applications

    NASA Astrophysics Data System (ADS)

    Jeans, Albert; Almanza-Workman, Marcia; Cobene, Robert; Elder, Richard; Garcia, Robert; Gomez-Pancorbo, Fernando; Jackson, Warren; Jam, Mehrban; Kim, Han-Jun; Kwon, Ohseung; Luo, Hao; Maltabes, John; Mei, Ping; Perlov, Craig; Smith, Mark; Taussig, Carl; Jeffrey, Frank; Braymen, Steve; Hauschildt, Jason; Junge, Kelly; Larson, Don; Stieler, Dan

    2010-03-01

    A solution to the problems of roll-to-roll lithography on flexible substrates is presented. We have developed a roll-toroll imprint lithography technique to fabricate active matrix transistor backplanes on flexible webs of polyimide that have a blanket material stack of metals, dielectrics, and semiconductors. Imprint lithography produces a multi-level 3- dimensional mask that is then successively etched to pattern the underlying layers into the desired structures. This process, Self-Aligned Imprint Lithography (SAIL), solves the layer-to-layer alignment problem because all masking levels are created with one imprint step. The processes and equipment required for complete roll-to-roll SAIL fabrication will be described. Emphasis will be placed on the advances in the roll-to-roll imprint process which have enabled us to produce working transistor arrays.

  5. Roll-to-Roll Atomic Layer Deposition for Ultrabarriers

    NASA Astrophysics Data System (ADS)

    Yersak, Alexander

    Atomic layer deposition (ALD) is a bottom-up, gas phase, thin film deposition technique based on sequential, self-limiting binary surface reactions. The precise sub-nanometer film thickness control and conformal nature of this process have led to various commercial applications of ALD. However, ALD films are most commonly deposited in batch processes at low pressures, which raises throughput and/or cost concerns for many otherwise promising applications. This problem can be solved by spatial ALD (S-ALD) which is a version of the ALD technique where the precursors are separated in space rather than time. We have demonstrated the first atmospheric pressure roll-to-roll (R2R) ALD web coating system. A thickness uniformity of +/-2% was achieved across the web. ALD cycle times as low as 76 ms were demonstrated with a web speed of 1 m/s and a vertical gap height of 0.5 mm. Extrinsic defects in the ALD films were investigated, and a predictive cluster model was proposed, and was demonstrated with a residual (i.e. difference between the actual defect counts and those predicted by the cluster model) of <10%. A R2R ALD web coating tool with molecular layer deposition (MLD) capabilities was investigated and achieved a defect density <10 /cm2. A hyperbaric corrosion chamber with in situ monitoring of film thickness was demonstrated with the ability to characterize R2R ALD films using water dissolution as a metric. ALD SiO2 films were determined to be dissolution-predictable with a predicted dissolution rate of 3.7 nm/year at physiological temperatures. ALD TiO2 films were observed with no measurable dissolution in 150 °C water over the measurement period of 12 days.

  6. 76 FR 35400 - Continuation of Suspended Antidumping Duty Investigation on Certain Hot-Rolled Flat-Rolled Carbon...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-17

    ... International Trade Administration Continuation of Suspended Antidumping Duty Investigation on Certain Hot...'') that termination of the suspended antidumping duty investigation on certain hot-rolled flat-rolled carbon quality steel products (``hot- rolled steel'') from the Russian Federation (``Russia'')...

  7. Roll Casting of Aluminum Alloy Clad Strip

    SciTech Connect

    Nakamura, R.; Tsuge, H.; Haga, T.; Watari, H.; Kumai, S.

    2011-01-17

    Casting of aluminum alloy three layers of clad strip was tried using the two sets of twin roll casters, and effects of the casting parameters on the cladding conditions were investigated. One twin roll caster was mounted on the other twin roll caster. Base strip was 8079 aluminum alloy and overlay strips were 6022 aluminum alloy. Effects of roll-load of upper and lower casters and melt temperature of the lower caster were investigated. When the roll-load of the upper and lower caster was large enough, the overlay strip could be solidified and be connected. The overlay strip could be connected when the melt of the overlay strip cast by the lower caster was low enough. Sound three layers of clad strip could be cast by proper conditions.

  8. Aerodynamics of a rolling airframe missile

    NASA Astrophysics Data System (ADS)

    Tisserand, L. E.

    1981-05-01

    For guidance-related reasons, there is considerable interest in rolling missiles having single-plane steering capability. To aid the aerodynamic design of these airframes, a unique investigation into the aerodynamics of a rolling, steering missile has been carried out. It represents the first known attempt to measure in a wind tunnel the aerodynamic forces and moments that act on a spinning body-canard-tail configuration that exercises canard steering in phase with body roll position. Measurements were made with the model spinning at steady-state roll rates ranging from 15 to 40 Hz over an angle-of-attack range up to about 16 deg. This short, exploratory investigation has demonstrated that a better understanding and a more complete definition of the aerodynamics of rolling, steering vehicles can be developed by way of simulative wind-tunnel testing.

  9. Automated Procedure for Roll Pass Design

    NASA Astrophysics Data System (ADS)

    Lambiase, F.; Langella, A.

    2009-04-01

    The aim of this work has been to develop an automatic roll pass design method, capable of minimizing the number of roll passes. The adoption of artificial intelligence technologies, particularly expert systems, and a hybrid model for the surface profile evaluation of rolled bars, has allowed us to model the search for the minimal sequence with a tree path search. This approach permitted a geometrical optimization of roll passes while allowing automation of the roll pass design process. Moreover, the heuristic nature of the inferential engine contributes a great deal toward reducing search time, thus allowing such a system to be employed for industrial purposes. Finally, this new approach was compared with other recently developed automatic systems to validate and measure possible improvements among them.

  10. Comparative leaf development in angiosperms.

    PubMed

    Tsukaya, Hirokazu

    2014-02-01

    Recent accumulation of our knowledge on basic leaf development mechanisms in model angiosperm species has allowed us to pursue evolutionary development (evo/devo) studies of various kinds of leaf development. As a result, unexpected findings and clues have been unearthed aiding our understanding of the mechanisms involved in the diversity of leaf morphology, although the covered remain limited. In this review, we highlight recent findings of diversified leaf development in angiosperms.

  11. Bacterial leaf spot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial leaf spot has been reported in Australia (Queensland), Egypt, El Salvador, India, Japan, Nicaragua, Sudan, and the United States (Florida, Iowa, Kansas, Maryland, and Wisconsin). It occasionally causes locally severe defoliation and post-emergence damping-off and stunting. The disease is...

  12. Maple Leaf Outdoor Centre.

    ERIC Educational Resources Information Center

    Maguire, Molly; Gunton, Ric

    2000-01-01

    Maple Leaf Outdoor Centre (Ontario) has added year-round outdoor education facilities and programs to help support its summer camp for disadvantaged children. Schools, youth centers, religious groups, and athletic teams conduct their own programs, collaborate with staff, or use staff-developed programs emphasizing adventure education and personal…

  13. Structure of large dsDNA viruses

    PubMed Central

    Klose, Thomas; Rossmann, Michael G.

    2015-01-01

    Nucleocytoplasmic large dsDNA viruses (NCLDVs) encompass an ever-increasing group of large eukaryotic viruses, infecting a wide variety of organisms. The set of core genes shared by all these viruses includes a major capsid protein with a double jelly-roll fold forming an icosahedral capsid, which surrounds a double layer membrane that contains the viral genome. Furthermore, some of these viruses, such as the members of the Mimiviridae and Phycodnaviridae have a unique vertex that is used during infection to transport DNA into the host. PMID:25003382

  14. Major tomato viruses in the Mediterranean basin.

    PubMed

    Hanssen, Inge M; Lapidot, Moshe

    2012-01-01

    Tomato (Solanum lycopersicum L.) originated in South America and was brought to Europe by the Spaniards in the sixteenth century following their colonization of Mexico. From Europe, tomato was introduced to North America in the eighteenth century. Tomato plants show a wide climatic tolerance and are grown in both tropical and temperate regions around the world. The climatic conditions in the Mediterranean basin favor tomato cultivation, where it is traditionally produced as an open-field plant. However, viral diseases are responsible for heavy yield losses and are one of the reasons that tomato production has shifted to greenhouses. The major tomato viruses endemic to the Mediterranean basin are described in this chapter. These viruses include Tomato yellow leaf curl virus, Tomato torrado virus, Tomato spotted wilt virus, Tomato infectious chlorosis virus, Tomato chlorosis virus, Pepino mosaic virus, and a few minor viruses as well.

  15. Molecular identification of Ageratum enation virus, betasatellite and alphasatellite molecules isolated from yellow vein diseased Amaranthus cruentus in India.

    PubMed

    Srivastava, Ashish; Raj, Shri Krishana; Kumar, Susheel; Snehi, Sunil Kumar; Kulshreshtha, Aditya; Hallan, Vipin; Pande, Sunil Sohanlal

    2013-12-01

    Natural occurrence of yellow vein disease on Amaranthus cruentus was observed at Lucknow, India in the year 2008. The causal virus was successfully transmitted through whiteflies (Bemisia tabaci) from diseased A. cruentus to healthy seedlings of A. cruentus and other test species which indicated begomovirus infection. The begomovirus DNA-A, betasatellite, and alphasatellite components associated with yellow vein disease were amplified by rolling circle amplification using Ø-29 DNA polymerase from diseased A. cruentus and characterized by their sequence analyses. The begomovirus DNA-A genome contained six ORFs: AV2 and AV1 in virion sense and AC3, AC2, AC1, and AC4 in complementary sense strand; and a non-translated intergenic region having the conserved geminiviral nonanucleotide sequence. The virus isolate showed 97-99% sequence identities and close phylogenetic relationships with various isolates of Ageratum enation virus (AgEV); therefore, the isolate under study was identified as AgEV. The beta- and alphasatellite molecules were also identified to be associated with the disease based on their high sequence identities and close phylogenetic relationships with the respective molecules reported worldwide. Co-infiltration of agro-infectious clones of AgEV DNA-A and its betasatellite DNA induced leaf curl and enation symptoms after 25-35 days on A. cruentus, Nicotiana benthamiana, and N. glutinosa plants. We report the association of AgEV, betasatellite and alphasatellite components with yellow vein disease of A. cruentus from India.

  16. Rolling Contact Force Energy Reconstruction

    NASA Astrophysics Data System (ADS)

    BRACCIALI, A.; CASCINI, G.

    2000-09-01

    Knowledge of the forces at the wheel-rail contact is fundamental to estimate the consequences in terms of noise and vibration. The traditional use of strain gauges mounted on the wheel web and axle is not capable of determining the high-frequency content of the contact force. Measurements made on the rail are characterized by the spatial variability of input-output transfer functions which makes it difficult to estimate the contact force by simple inversion of the point frequency response function. In this study the problem of rolling contact force reconstruction has been approached through the following steps: (i) the track has been characterized precisely for a finite length by the analysis of the time series of several impacts supplied with an instrumented hammer by using an ARMAX model that proved to be capable of modelling the vertical dynamics of the rail up to 5 kHz; (ii) the response of the rail has been simulated with a random force acting on the system, and the variability of the transfer function has been taken into account by distributing the force on adjacent elements; (iii) the simulated response has been compared with the rail acceleration measured for the passage of several trains; (iv) the wheel-rail contact force has been estimated with a closed-loop algorithm. It has thus been possible to reconstruct the13octave power spectrum of contact forces with a simple and stable iterative procedure. Forces reconstructed from different sensors were found to be practically the same for a given wheel; forces from nominally similar wheels are statistically examined and partial results of comparisons made on different rolling stock are shown.

  17. Heartland Virus

    MedlinePlus

    ... Vector-Borne Diseases (DVBD) NCEZID Share Compartir Heartland virus On this Page What is Heartland virus? How ... Do I Need to Know? What is Heartland virus? Heartland virus belongs to a family of viruses ...

  18. Inflation with a constant rate of roll

    SciTech Connect

    Motohashi, Hayato; Starobinsky, Alexei A.; Yokoyama, Jun'ichi E-mail: alstar@landau.ac.ru

    2015-09-01

    We consider an inflationary scenario where the rate of inflaton roll defined by {sup ··}φ/H φ-dot remains constant. The rate of roll is small for slow-roll inflation, while a generic rate of roll leads to the interesting case of 'constant-roll' inflation. We find a general exact solution for the inflaton potential required for such inflaton behaviour. In this model, due to non-slow evolution of background, the would-be decaying mode of linear scalar (curvature) perturbations may not be neglected. It can even grow for some values of the model parameter, while the other mode always remains constant. However, this always occurs for unstable solutions which are not attractors for the given potential. The most interesting particular cases of constant-roll inflation remaining viable with the most recent observational data are quadratic hilltop inflation (with cutoff) and natural inflation (with an additional negative cosmological constant). In these cases even-order slow-roll parameters approach non-negligible constants while the odd ones are asymptotically vanishing in the quasi-de Sitter regime.

  19. Inflation with a constant rate of roll

    NASA Astrophysics Data System (ADS)

    Motohashi, Hayato; Starobinsky, Alexei A.; Yokoyama, Jun'ichi

    2015-09-01

    We consider an inflationary scenario where the rate of inflaton roll defined by ̈phi/H dot phi remains constant. The rate of roll is small for slow-roll inflation, while a generic rate of roll leads to the interesting case of 'constant-roll' inflation. We find a general exact solution for the inflaton potential required for such inflaton behaviour. In this model, due to non-slow evolution of background, the would-be decaying mode of linear scalar (curvature) perturbations may not be neglected. It can even grow for some values of the model parameter, while the other mode always remains constant. However, this always occurs for unstable solutions which are not attractors for the given potential. The most interesting particular cases of constant-roll inflation remaining viable with the most recent observational data are quadratic hilltop inflation (with cutoff) and natural inflation (with an additional negative cosmological constant). In these cases even-order slow-roll parameters approach non-negligible constants while the odd ones are asymptotically vanishing in the quasi-de Sitter regime.

  20. 'Slings' enable neutrophil rolling at high shear.

    PubMed

    Sundd, Prithu; Gutierrez, Edgar; Koltsova, Ekaterina K; Kuwano, Yoshihiro; Fukuda, Satoru; Pospieszalska, Maria K; Groisman, Alex; Ley, Klaus

    2012-08-16

    Most leukocytes can roll along the walls of venules at low shear stress (1 dyn cm−2), but neutrophils have the ability to roll at tenfold higher shear stress in microvessels in vivo. The mechanisms involved in this shear-resistant rolling are known to involve cell flattening and pulling of long membrane tethers at the rear. Here we show that these long tethers do not retract as postulated, but instead persist and appear as 'slings' at the front of rolling cells. We demonstrate slings in a model of acute inflammation in vivo and on P-selectin in vitro, where P-selectin-glycoprotein-ligand-1 (PSGL-1) is found in discrete sticky patches whereas LFA-1 is expressed over the entire length on slings. As neutrophils roll forward, slings wrap around the rolling cells and undergo a step-wise peeling from the P-selectin substrate enabled by the failure of PSGL-1 patches under hydrodynamic forces. The 'step-wise peeling of slings' is distinct from the 'pulling of tethers' reported previously. Each sling effectively lays out a cell-autonomous adhesive substrate in front of neutrophils rolling at high shear stress during inflammation.

  1. Further Insights Into The Epidemiology And Monitoring Practices Of Tomato Viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are a number of serious virus threats to tomato production in Florida. These include the whitefly-transmitted Tomato yellow leaf curl virus (TYLCV) and, more recently, Groundnut ringspot virus (GRSV) and Tomato chlorotic spot virus (TCSV) which are both vectored by thrips. GRSV and TCSV are cl...

  2. Epidemiology and Association of Four Insect-Vectored Viruses in Florida Watermelon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whitefly-transmitted Squash vein yellowing virus (SqVYV), Cucurbit leaf crumple virus (CuLCrV), Cucurbit yellow stunting disorder virus (CYSDV) and aphid-transmitted Papaya ringspot virus type W (PRSV-W) have had serious impact on watermelon production in southwest and west-central Florida in the pa...

  3. Signal and power roll ring testing update

    NASA Technical Reports Server (NTRS)

    Smith, Dennis W.

    1989-01-01

    The development of the roll ring as a long-life, low-torque alternative to the slip ring is discussed. A roll ring consists of one or more circular flexures captured by their own spring force in the annular space between two concentric conductors or contact rings. The advantages of roll rings over other types of electrical transfer devices are: extremely low drag torque, high transfer efficiencies in high-power configurations, extremely low wear debris generation, long life, and low weight for high-power applications.

  4. Biology and interactions of two distinct monopartite begomoviruses and betasatellites associated with radish leaf curl disease in India

    PubMed Central

    2012-01-01

    Background Emerging whitefly transmitted begomoviruses are major pathogens of vegetable and fibre crops throughout the world, particularly in tropical and sub-tropical regions. Mutation, pseudorecombination and recombination are driving forces for the emergence and evolution of new crop-infecting begomoviruses. Leaf curl disease of field grown radish plants was noticed in Varanasi and Pataudi region of northern India. We have identified and characterized two distinct monopartite begomoviruses and associated beta satellite DNA causing leaf curl disease of radish (Raphanus sativus) in India. Results We demonstrate that RaLCD is caused by a complex of two Old World begomoviruses and their associated betasatellites. Radish leaf curl virus-Varanasi is identified as a new recombinant species, Radish leaf curl virus (RaLCV) sharing maximum nucleotide identity of 87.7% with Tomato leaf curl Bangladesh virus-[Bangladesh:2] (Accession number AF188481) while the virus causing radish leaf curl disease-Pataudi is an isolate of Croton yellow vein mosaic virus-[India] (CYVMV-IN) (Accession number AJ507777) sharing 95.8% nucleotide identity. Further, RDP analysis revealed that the RaLCV has a hybrid genome, a putative recombinant between Euphorbia leaf curl virus and Papaya leaf curl virus. Cloned DNA of either RaLCV or CYVMV induced mild leaf curl symptoms in radish plants. However, when these clones (RaLCV or CYVMV) were individually co-inoculated with their associated cloned DNA betasatellite, symptom severity and viral DNA levels were increased in radish plants and induced typical RaLCD symptoms. To further extend these studies, we carried out an investigation of the interaction of these radish-infecting begomoviruses and their associated satellite, with two tomato infecting begomoviruses (Tomato leaf curl Gujarat virus and Tomato leaf curl New Delhi virus). Both of the tomato-infecting begomoviruses showed a contrasting and differential interaction with DNA satellites, not

  5. Roll paper pilot. [mathematical model for predicting pilot rating of aircraft in roll task

    NASA Technical Reports Server (NTRS)

    Naylor, F. R.; Dillow, J. D.; Hannen, R. A.

    1973-01-01

    A mathematical model for predicting the pilot rating of an aircraft in a roll task is described. The model includes: (1) the lateral-directional aircraft equations of motion; (2) a stochastic gust model; (3) a pilot model with two free parameters; and (4) a pilot rating expression that is a function of rms roll angle and the pilot lead time constant. The pilot gain and lead time constant are selected to minimize the pilot rating expression. The pilot parameters are then adjusted to provide a 20% stability margin and the adjusted pilot parameters are used to compute a roll paper pilot rating of the aircraft/gust configuration. The roll paper pilot rating was computed for 25 aircraft/gust configurations. A range of actual ratings from 2 to 9 were encountered and the roll paper pilot ratings agree quite well with the actual ratings. In addition there is good correlation between predicted and measured rms roll angle.

  6. Why Low Bounce Balls Exhibit High Rolling Resistance

    ERIC Educational Resources Information Center

    Cross, Rod

    2015-01-01

    A simple experiment is described to measure the coefficient of rolling friction for a low bounce ball rolling on a horizontal surface. As observed previously by others, the coefficient increased with rolling speed. The energy loss due to rolling friction can be explained in terms of the measured coefficient of restitution for the ball, meaning…

  7. A Novel DNA Motif Contributes to Selective Replication of a Geminivirus-Associated Betasatellite by a Helper Virus-Encoded Replication-Related Protein

    PubMed Central

    Zhang, Tong; Xu, Xiongbiao; Huang, Changjun; Qian, Yajuan; Li, Zhenghe

    2015-01-01

    ABSTRACT Rolling-circle replication of single-stranded genomes of plant geminiviruses is initiated by sequence-specific DNA binding of the viral replication-related protein (Rep) to its cognate genome at the replication origin. Monopartite begomovirus-associated betasatellites can be trans replicated by both cognate and some noncognate helper viruses, but the molecular basis of replication promiscuity of betasatellites remains uncharacterized. Earlier studies showed that when tomato yellow leaf curl China virus (TYLCCNV) or tobacco curly shoot virus (TbCSV) is coinoculated with both cognate and noncognate betasatellites, the cognate betasatellite dominates over the noncognate one at the late stages of infection. In this study, we constructed reciprocal chimeric betasatellites between tomato yellow leaf curl China betasatellite and tobacco curly shoot betasatellite and assayed their competitiveness against wild-type betasatellite when coinoculated with TYLCCNV or TbCSV onto plants. We mapped a region immediately upstream of the conserved rolling-circle cruciform structure of betasatellite origin that confers the cognate Rep-mediated replication advantage over the noncognate satellite. DNase I protection and in vitro binding assays further identified a novel sequence element termed Rep-binding motif (RBM), which specifically binds to the cognate Rep protein and to the noncognate Rep, albeit at lower affinity. Furthermore, we showed that RBM-Rep binding affinity is correlated with betasatellite replication efficiency in protoplasts. Our data suggest that although strict specificity of Rep-mediated replication does not exist, betasatellites have adapted to their cognate Reps for efficient replication during coevolution. IMPORTANCE Begomoviruses are numerous circular DNA viruses that cause devastating diseases of crops worldwide. Monopartite begomoviruses are frequently associated with betasatellites which are essential for induction of typical disease symptoms

  8. Leaf absorbance and photosynthesis

    NASA Technical Reports Server (NTRS)

    Schurer, Kees

    1994-01-01

    The absorption spectrum of a leaf is often thought to contain some clues to the photosynthetic action spectrum of chlorophyll. Of course, absorption of photons is needed for photosynthesis, but the reverse, photosynthesis when there is absorption, is not necessarily true. As a check on the existence of absorption limits we measured spectra for a few different leaves. Two techniques for measuring absorption have been used, viz. the separate determination of the diffuse reflectance and the diffuse transmittance with the leaf at a port of an integrating sphere and the direct determination of the non-absorbed fraction with the leaf in the sphere. In a cross-check both methods yielded the same results for the absorption spectrum. The spectrum of a Fuchsia leaf, covering the short-wave region from 350 to 2500 nm, shows a high absorption in UV, blue and red, the well known dip in the green and a steep fall-off at 700 nm. Absorption drops to virtually zero in the near infrared, with subsequent absorptions, corresponding to the water absorption bands. In more detailed spectra, taken at 5 nm intervals with a 5 nm bandwidth, differences in chlorophyll content show in the different depths of the dip around 550 nm and in a small shift of the absorption edge at 700 nm. Spectra for Geranium (Pelargonium zonale) and Hibiscus (with a higher chlorophyll content) show that the upper limit for photosynthesis can not be much above 700 nm. No evidence, however, is to be seen of a lower limit for photosynthesis and, in fact, some experiments down to 300 nm still did not show a decrease of the absorption although it is well recognized that no photosynthesis results with 300 nm wavelengths.

  9. Widespread distribution and a new recombinant species of Brazilian virus associated with cotton blue disease

    PubMed Central

    Silva, TF; Corrêa, RL; Castilho, Y; Silvie, P; Bélot, J-L; Vaslin, MFS

    2008-01-01

    Background Cotton blue disease (CBD), an important global cotton crop pathology responsible for major economic losses, is prevalent in the major cotton-producing states of Brazil. Typical CBD symptoms include stunting due to internodal shortening, leaf rolling, intense green foliage, and yellowing veins. Atypical CBD symptoms, including reddish and withered leaves, were also observed in Brazilian cotton fields in 2007. Recently, a Polerovirus named Cotton leafroll dwarf virus (CLRDV) was shown to be associated with CBD. Results To understand the distribution and genetic diversity of CLRDV in Brazil, we analyzed 23 CBD-symptomatic plants from susceptible cotton varieties originating from five of the six most important cotton-growing states, from 2004–2007. Here, we report on CLRDV diversity in plants with typical or atypical CBD symptoms by comparing viral coat protein, RNA polymerase (RdRp), and intergenic region genomic sequences. Conclusion The virus had a widespread distribution with a low genetic diversity; however, three divergent isolates were associated with atypical CBD symptoms. These divergent isolates had a CLRDV-related coat protein but a distinct RdRp sequence, and probably arose from recombination events. Based on the taxonomic rules for the family Luteoviridae, we propose that these three isolates represent isolates of a new species in the genus Polerovirus. PMID:18937850

  10. Moesin regulates neutrophil rolling velocity in vivo.

    PubMed

    Matsumoto, Masanori; Hirata, Takako

    2016-01-01

    During inflammation, the selectin-induced slow rolling of neutrophils on venules cooperates with chemokine signaling to mediate neutrophil recruitment into tissues. Previous studies identified P-selectin glycoprotein ligand-1 (PSGL-1) and CD44 as E-selectin ligands that activate integrins to induce slow rolling. We show here that in TNF-α-treated cremaster muscle venules, slow leukocyte rolling was impaired in mice deficient in moesin, a member of the ezrin-radixin-moesin (ERM) family. Accordingly, neutrophil recruitment in a peritonitis model was decreased in moesin-deficient mice when chemokine signaling was blocked with pertussis toxin. These results suggest that moesin contributes to the slow rolling and subsequent recruitment of neutrophils during inflammation.

  11. Mathematical modeling of deformation during hot rolling

    SciTech Connect

    Jin, D.; Stachowiak, R.G.; Samarasekera, I.V.; Brimacombe, J.K.

    1994-12-31

    The deformation that occurs in the roll bite during the hot rolling of steel, particularly the strain-rate and strain distribution, has been mathematically modeled using finite-element analysis. In this paper three different finite-element models are compared with one another and with industrial measurements. The first model is an Eulerian analysis based on the flow formulation method, while the second utilizes an Updated Lagrangian approach. The third model is based on a commercially available program DEFORM which also utilizes a Lagrangian reference frame. Model predictions of strain and strain-rate distribution, particularly near the surface of the slab, are strongly influenced by the treatment of friction at the boundary and the magnitude of the friction coefficient or shear factor. Roll forces predicted by the model have been compared with industrial rolling loads from a seven-stand hot-strip mill.

  12. Roll Damping Characterisation Program: User Guide

    DTIC Science & Technology

    2014-06-01

    sallying test. The Defence Science and Technology Organisation (DSTO) have developed a software-based tool called the Roll Damping Characterisation...Murray Riding Maritime Division Murray obtained a Bachelor of Science (Honours) Degree from the

  13. Next-Generation Space Ambitions Keep Rolling

    NASA Video Gallery

    As space shuttle Atlantis rolled to its new home at the Kennedy Space Center Visitor Complex earlier this month, NASA and its commercial crew partners reflected on the Space Shuttle Program's treme...

  14. Roll measurement of Tevatron dipoles and quadrupoles

    SciTech Connect

    Volk, J.T.; Elementi, L.; Gollwitzer, K.; Jostlein, H.; Nobrega, F.; Shiltsev, V.; Stefanski, R.

    2006-09-01

    In 2003 a simple digital level system was developed to allow for rapid roll measurements of all dipoles and quadrupoles in the Tevatron. The system uses a Mitutoyo digital level and a PC running MS WINDOWS XP and LAB VIEW to acquire data on the upstream and downstream roll of each magnet. The system is sufficiently simple that all 1,000 magnets in the Tevatron can be measured in less than 3 days. The data can be quickly processed allowing for correction of rolled magnets by the Fermilab alignment group. Data will be presented showing the state of the Tevatron in 2003 and the changes in rolls as measured in each shutdown since then.

  15. 49 CFR 393.134 - What are the rules for securing roll-on/roll-off or hook lift containers?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 5 2013-10-01 2013-10-01 false What are the rules for securing roll-on/roll-off... Shifting and Falling Cargo Specific Securement Requirements by Commodity Type § 393.134 What are the rules for securing roll-on/roll-off or hook lift containers? (a) Applicability. The rules in this...

  16. Plasmid Rolling-Circle Replication.

    PubMed

    Ruiz-Masó, J A; MachóN, C; Bordanaba-Ruiseco, L; Espinosa, M; Coll, M; Del Solar, G

    2015-02-01

    Plasmids are DNA entities that undergo controlled replication independent of the chromosomal DNA, a crucial step that guarantees the prevalence of the plasmid in its host. DNA replication has to cope with the incapacity of the DNA polymerases to start de novo DNA synthesis, and different replication mechanisms offer diverse solutions to this problem. Rolling-circle replication (RCR) is a mechanism adopted by certain plasmids, among other genetic elements, that represents one of the simplest initiation strategies, that is, the nicking by a replication initiator protein on one parental strand to generate the primer for leading-strand initiation and a single priming site for lagging-strand synthesis. All RCR plasmid genomes consist of a number of basic elements: leading strand initiation and control, lagging strand origin, phenotypic determinants, and mobilization, generally in that order of frequency. RCR has been mainly characterized in Gram-positive bacterial plasmids, although it has also been described in Gram-negative bacterial or archaeal plasmids. Here we aim to provide an overview of the RCR plasmids' lifestyle, with emphasis on their characteristic traits, promiscuity, stability, utility as vectors, etc. While RCR is one of the best-characterized plasmid replication mechanisms, there are still many questions left unanswered, which will be pointed out along the way in this review.

  17. Strip edge cracking simulation in cold rolling

    NASA Astrophysics Data System (ADS)

    Hubert, C.; Dubar, L.; Dubar, M.; Dubois, A.

    2011-01-01

    This research work focuses on a specific defect which occurs during cold rolling of steel strips: edge-serration. Investigations on the industrial processes have led to the conclusion that this defect is the result of the edge-trimming and cold rolling sequences. The aim of this research work is to analyze the effect of the cutting process and the cold rolling on cracks occurrence, especially on strip edges. This study is performed using an experimental testing stand called Upsetting Rolling Test (URT). It allows to reproduce cold rolling contact parameters such as forward slip, reduction ratio and friction coefficients. Specimens sampled near trimmed industrial strip edges are deformed using the URT stand. Two sets of specimens with different stress states, obtained by annealing, are submitted to two reduction passes with extreme forward slips. Scanning electron microscopy observations added to 3D optical surface profiler topographies show that on one hand, forward slip has a major effect on cracks opening. On the other hand, cracks opening decreases according to high roll strip speed gradient. Concerning the heat-treated specimens, no crack appeared after all reduction passes, showing a large influence of the cutting process and consequently of the local stress state in the vicinity of the burnish and fracture regions.

  18. Ultra slow-roll G inflation

    NASA Astrophysics Data System (ADS)

    Hirano, Shin'ichi; Kobayashi, Tsutomu; Yokoyama, Shuichiro

    2016-11-01

    The conventional slow-roll approximation is broken in the so-called "ultra slow-roll" models of inflation, for which the inflaton potential is exactly (or extremely) flat. The interesting nature of (canonical) ultra slow-roll inflation is that the curvature perturbation grows on superhorizon scales, but has a scale-invariant power spectrum. We study the ultra slow-roll inflationary dynamics in the presence of noncanonical kinetic terms of the scalar field, namely ultra slow-roll G inflation. We compute the evolution of the curvature perturbation and show that the primordial power spectrum follows a broken power law with an oscillation feature. It is demonstrated that this could explain the lack of large-scale power in the cosmic microwave background temperature anisotropies. We also point out that the violation of the null energy condition is prohibited in ultra slow-roll G inflation, and hence a blue tensor tilt is impossible as long as inflation is driven by the potential. This statement is, however, not true if the energy density is dominated by the kinetic energy of the scalar field.

  19. Strip edge cracking simulation in cold rolling

    SciTech Connect

    Hubert, C.; Dubar, L.; Dubar, M.; Dubois, A.

    2011-01-17

    This research work focuses on a specific defect which occurs during cold rolling of steel strips: edge-serration. Investigations on the industrial processes have led to the conclusion that this defect is the result of the edge-trimming and cold rolling sequences. The aim of this research work is to analyze the effect of the cutting process and the cold rolling on cracks occurrence, especially on strip edges.This study is performed using an experimental testing stand called Upsetting Rolling Test (URT). It allows to reproduce cold rolling contact parameters such as forward slip, reduction ratio and friction coefficients. Specimens sampled near trimmed industrial strip edges are deformed using the URT stand. Two sets of specimens with different stress states, obtained by annealing, are submitted to two reduction passes with extreme forward slips.Scanning electron microscopy observations added to 3D optical surface profiler topographies show that on one hand, forward slip has a major effect on cracks opening. On the other hand, cracks opening decreases according to high roll strip speed gradient. Concerning the heat-treated specimens, no crack appeared after all reduction passes, showing a large influence of the cutting process and consequently of the local stress state in the vicinity of the burnish and fracture regions.

  20. A multiple reverse transcription-polymerase chain reaction assay for simultaneous detection and differentiation of latent viruses and apscarviroids in apple trees

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Apple chlorotic leaf spot virus (ACLSV), Apple stem grooving virus (ASGV), and Apple stem pitting virus (ASPV) are three latent viruses frequently occurring in apple trees worldwide. In field orchards, these viruses are frequently found in a mixed infection with viroids in the genus Apscarviroid, in...

  1. The worldwide leaf economics spectrum.

    PubMed

    Wright, Ian J; Reich, Peter B; Westoby, Mark; Ackerly, David D; Baruch, Zdravko; Bongers, Frans; Cavender-Bares, Jeannine; Chapin, Terry; Cornelissen, Johannes H C; Diemer, Matthias; Flexas, Jaume; Garnier, Eric; Groom, Philip K; Gulias, Javier; Hikosaka, Kouki; Lamont, Byron B; Lee, Tali; Lee, William; Lusk, Christopher; Midgley, Jeremy J; Navas, Marie-Laure; Niinemets, Ulo; Oleksyn, Jacek; Osada, Noriyuki; Poorter, Hendrik; Poot, Pieter; Prior, Lynda; Pyankov, Vladimir I; Roumet, Catherine; Thomas, Sean C; Tjoelker, Mark G; Veneklaas, Erik J; Villar, Rafael

    2004-04-22

    Bringing together leaf trait data spanning 2,548 species and 175 sites we describe, for the first time at global scale, a universal spectrum of leaf economics consisting of key chemical, structural and physiological properties. The spectrum runs from quick to slow return on investments of nutrients and dry mass in leaves, and operates largely independently of growth form, plant functional type or biome. Categories along the spectrum would, in general, describe leaf economic variation at the global scale better than plant functional types, because functional types overlap substantially in their leaf traits. Overall, modulation of leaf traits and trait relationships by climate is surprisingly modest, although some striking and significant patterns can be seen. Reliable quantification of the leaf economics spectrum and its interaction with climate will prove valuable for modelling nutrient fluxes and vegetation boundaries under changing land-use and climate.

  2. Molecular characterization and construction of an infectious clone of a pepper isolate of Beet curly top Iran virus

    PubMed Central

    Eini, Omid; Ebadzad Sahraei, Ghazal; Behjatnia, Seyed Ali Akbar

    2016-01-01

    Geminiviruses cause curly top disease, in dicotyledonous plants which constrains host crop production. Beet curly top Iran virus (BCTIV) is a widespread Becurtovirus (family Geminiviridae) in numerous areas within Iran. In this study, we isolated and analyzed a full-length genomic DNA of a new variant of BCTIV from pepper crops in the Kaftark region, east of Shiraz (proposed acronym: BCTIV-Kaf [IR: Kaf:2016:Pepper]). Infected pepper plants showed shortening of internodes, severe interveinal chlorosis, upward leaf rolling and leaf curling. Sequence and phylogenetic analysis showed this BCTIV variant grouped with sugar beet isolates of BCTIV and has the highest similarity to a sugar beet BCTIV isolate from Negar town in Kerman province, Iran. It was more distantly related to a bean isolate of BCTIV from northeast region of Iran. A tandem repeat partial dimmer of BCTIV was constructed and found to be infectious in pepper, tomato and Nicotiana benthamiana plants. Results of this study indicated that BCTIV-Kaf is a new variant of BCTIV infecting pepper plants in Shiraz and that geographic location rather than the type of host plant has more effect on genetic diversity of BCTIV in Iran. PMID:28097164

  3. Structures of giant icosahedral eukaryotic dsDNA viruses

    PubMed Central

    Xiao, Chuan; Rossmann, Michael G.

    2011-01-01

    In the last twenty years, numerous giant, dsDNA, icosahedral viruses have been discovered and assigned to the nucleocytoplasmic large dsDNA virus (NCLDV) clade. The major capsid proteins of these viruses consist of two consecutive jelly-roll domains, assembled into trimers, with pseudo 6-fold symmetry. The capsomers are assembled into arrays that have either p6 (as in Paramecium bursaria Chlorella virus-1) or p3 symmetry (as in Mimivirus). Most of the NCLDV viruses have a membrane that separates the nucleocapsid from the external capsid. PMID:21909343

  4. 75 FR 64246 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil: Correction to Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-19

    ... International Trade Administration Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil... published a notice of antidumping duty order for certain hot-rolled flat-rolled carbon-quality steel products from Brazil. See Antidumping Duty Order: Certain Hot-Rolled Flat-Rolled Carbon-Quality...

  5. 77 FR 72820 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From the Russian Federation; 2010-2011...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-06

    ... International Trade Administration Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From the Russian... Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products from the Russian Federation (``the Agreement'') for the period July 1, 2010 through June 30, 2011. See Hot-Rolled Flat-Rolled ] Carbon-Quality...

  6. 75 FR 32160 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products from Brazil: Extension of Time Limit...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-07

    ... International Trade Administration Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products from Brazil... certain hot-rolled flat- rolled carbon-quality steel products from Brazil. See Agreement Suspending the Countervailing Duty Investigation on Hot-Rolled Flat- Rolled Carbon-Quality Steel From Brazil; Termination...

  7. 75 FR 75455 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil: Final Results of Full...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-03

    ... International Trade Administration Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil... certain hot-rolled flat-rolled carbon-quality steel products (hot-rolled steel) from Brazil, pursuant to.../COSIPA) \\2\\ and Companhia Siderurgica Nacional (CSN), producers of hot-rolled steel, and the...

  8. 75 FR 47541 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products from Brazil and Japan: Final Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-06

    ... International Trade Administration Hot-Rolled Flat-Rolled Carbon-Quality Steel Products from Brazil and Japan... Commerce (the Department) initiated sunset reviews of the antidumping duty orders on hot-rolled flat-rolled... hot- rolled flat-rolled carbon-quality steel products from Brazil and Japan pursuant to section...

  9. Experience in TMT with the use of cold lengthwise rolling in dead rolls

    NASA Astrophysics Data System (ADS)

    Agas'yants, G. A.; Semibratov, G. G.; Kodjaspirov, G. E.

    2007-01-01

    Experience in the thermomechanical treatment of long stepped preforms for shafts (including torsion ones), studs, forcing bolts, and other articles from high-strength and maraging steels with the use of cold lengthwise rolling in dead rolls is described. The used variants of TMT make it possible to obtain hardened highly loaded machine parts with high quality and performance parameters.

  10. Influence of Carbon Content and Rolling Temperature on Rolling Texture in 3 Pct Si Steel

    NASA Astrophysics Data System (ADS)

    Shingaki, Y.; Takashima, M.; Hayakawa, Y.

    2017-01-01

    Effects of carbon and rolling temperature up to 453 K (180 °C) on rolling texture of 3 pct Si steel at a reduction of 66 pct were investigated using a single crystal with an initial orientation of {110}<001>. With residual-level carbon, uniform slip deformation was observed in the specimen cold rolled at room temperature and most of initial orientation {110}<001> rotated to {111}<112> during the rolling. With carbon addition, the formation of the deformation twins and the shear bands were promoted in the specimen cold rolled at room temperature. Regions with {110}<001> were observed inside the shear bands. Warm-rolled specimen with residual-level carbon had microbands containing tiny {110}<001> regions. Warm-rolled specimen with carbon addition had both the shear bands and the microbands but no deformation twin. Additionally, there were unique band structures with rotated crystal orientation around the rolling direction from initial orientation {110}<001>. These experimental results suggest that the carbon addition inhibits dislocation migration by the increase of the critical resolved shear stress (CRSS) and that the high deformation temperature activates multiple slip systems by the reduction of CRSS and further that the carbon addition and high deformation temperature superimposed bring about the activation of symmetrical {110} slip systems additionally.

  11. Development of a Rolling Process Design Tool for Use in Improving Hot Roll Slab Recovery

    SciTech Connect

    2001-10-01

    The project goal is to develop a numerical modeling capability to optimize the hot rolling process used to produce aluminum plate. This tool will be used in the forming process so that loss of product will be minimized. Product lost in the rolling process requires the energy-intensive steps of remelting and reforming into an ingot.

  12. Comparing Acute Bouts of Sagittal Plane Progression Foam Rolling vs. Frontal Plane Progression Foam Rolling.

    PubMed

    Peacock, Corey A; Krein, Darren D; Antonio, Jose; Sanders, Gabriel J; Silver, Tobin A; Colas, Megan

    2015-08-01

    Many strength and conditioning professionals have included the use of foam rolling devices within a warm-up routine prior to both training and competition. Multiple studies have investigated foam rolling in regards to performance, flexibility, and rehabilitation; however, additional research is necessary in supporting the topic. Furthermore, as multiple foam rolling progressions exist, researching differences that may result from each is required. To investigate differences in foam rolling progressions, 16 athletically trained males underwent a 2-condition within-subjects protocol comparing the differences of 2 common foam rolling progressions in regards to performance testing. The 2 conditions included a foam rolling progression targeting the mediolateral axis of the body (FRml) and foam rolling progression targeting the anteroposterior axis (FRap). Each was administered in adjunct with a full-body dynamic warm-up. After each rolling progression, subjects performed National Football League combine drills, flexibility, and subjective scaling measures. The data demonstrated that FRml was effective at improving flexibility (p ≤ 0.05) when compared with FRap. No other differences existed between progressions.

  13. Practice of Improving Roll Deformation Theory in Strip Rolling Process Based on Boundary Integral Equation Method

    NASA Astrophysics Data System (ADS)

    Yuan, Zhengwen; Xiao, Hong; Xie, Hongbiao

    2014-02-01

    Precise strip-shape control theory is significant to improve rolled strip quality, and roll flattening theory is a primary part of the strip-shape theory. To improve the accuracy of roll flattening calculation based on semi-infinite body model, a new and more accurate roll flattening model is proposed in this paper, which is derived based on boundary integral equation method. The displacement fields of the finite length semi-infinite body on left and right sides are simulated by using finite element method (FEM) and displacement decay functions on left and right sides are established. Based on the new roll flattening model, a new 4Hi mill deformation model is established and verified by FEM. The new model is compared with Foppl formula and semi-infinite body model in different strip width, roll shifting value and bending force. The results show that the pressure and flattening between rolls calculated by the new model are more precise than other two models, especially near the two roll barrel edges.

  14. Inactivated eastern equine encephalomyelitis vaccine propagated in rolling-bottle cultures of chick embryo cells.

    PubMed

    Cole, F E

    1971-11-01

    A method was developed for the production of Eastern equine encephalomyelitis vaccine from virus grown in rolling-bottle cultures (840 cm(2) growth area) of chick embryo cells. The PE-6 strain of virus was propagated in chick embryo cell roller cultures maintained on serum-free medium 199 containing 0.25% human serum albumin and antibiotics (MM). A multiplicity of inoculum of 0.005 yielded acceptable titers of virus at a convenient harvest time of 18 to 24 hr and reduced the carry-over of extraneous material from the virus seed. Growth studies in which 100, 200, or 300 ml of MM was used showed that use of 300 ml of MM offered two advantages: (i) cytopathic effects were less at the 18- to 24-hr harvest time, thereby decreasing cellular material in the final product, and (ii) total virus yield was not substantially reduced, thus permitting large-scale production of virus for further processing. Studies on formalin inactivation at 37 C indicated that the virus was inactivated by 0.05% formalin within 12 to 16 hr and with 0.1% formalin within 6 to 8 hr. Antigen extinction tests in hamsters revealed excellent potency (e.g., median-effective-dose values of 0.069 to 0.012 ml) for both fluid and freeze-dried products. The advantages of the roller-bottle technique in vaccine production are discussed.

  15. Sensitivity analysis of roll load, torque and material properties in the roll forming process

    NASA Astrophysics Data System (ADS)

    Abeyrathna, Buddhika; Rolfe, Bernard; Hodgson, Peter; Weiss, Matthias

    2013-12-01

    Advanced High Strength Steel (AHSS) and Ultra High Strength Steel (UHSS) are increasingly used in the current automotive industry because of their high strength and weight saving potential. As a sheet forming process, roll forming is capable of forming such materials with precise dimensions, however a small change in processing may results in significant change in the material properties such as yield strength and hardening exponent from coil to coil or within the same coil. This paper presents the effect of yield strength and the hardening exponent on roll load, torque of the roll forming process and the longitudinal bow. The roll forming process is numerically simulated, and then the regression analysis and Analysis of Variance (ANOVA) techniques are employed to establish the relationships among the aforementioned parameters and to determine the percentage influence of material properties on longitudinal bow, roll load and torque.

  16. Research on the rolling moment in the symmetrical and asymmetrical rolling process

    NASA Astrophysics Data System (ADS)

    Alexa, V.; Raţiu, S. A.; Kiss, I.; Cioată, C. G.

    2017-01-01

    Research distribution the rolling moments symmetrical and asymmetrical report presents great importance both in theory and to introduce clarifications to the calculation of rolling resistance line assemblies. Clarifying individuals of metallic material deformation between the rolls single cylinder diameters act of any difference of work and analysis of advance and delay phenomena. Torque drive value for each of the rolling cylinders was done by reducing the thickness of the laminate samples, an experimental facility located in the laboratory of plastic deformation of the Faculty of Engineering Hunedoara. The analysis of research results show that in terms of power consumption for deformation and safety equipment in operation is rational for mills which require such a difference between the work rolls to execute about one cylinder operated.

  17. Applying contextual interference to the Pawlata roll.

    PubMed

    Smith, P J; Davies, M

    1995-12-01

    Contextual interference is manipulated by changing the practice order of a number of similar motor tasks, so that the learning context of each interferes with that of the other. The effect has been found to generalize to baseball batting, badminton serving and volleyball skills. The present study examined whether this practice technique could be applied to a Pawlata roll in a kayak. The study was further motivated by the fact that many instructors in Britain currently advocate learning the Pawlata roll in one direction only to a criterion of accuracy, thereafter transferring to the opposite direction. Contextual interference literature predicts that skill retention would be better served by practising on alternate sides. Accordingly, 16 undergraduate students with no kayaking experience were randomly allocated to either a low contextual interference group, which followed U'ren's (1993) recommendations, or a high contextual interference group, which practised the skill on alternate sides. The high contextual interference group took less time to acquire the skill, and were also quicker to achieve successful performance in retention (full roll) and transfer (half roll) tests, regardless of the direction of the roll, 1 week later. The time savings in practice were not expected, as acquisition under high contextual interference was improved rather than impaired. This finding suggests that bilateral transfer was increased by randomizing practice. These results are worthy of further investigation, in that they suggest that the recommended training methods may not be optimal.

  18. Magnon inflation: slow roll with steep potentials

    SciTech Connect

    Adshead, Peter; Blas, Diego; Burgess, C.P.; Hayman, Peter; Patil, Subodh P.

    2016-11-04

    We find multi-scalar effective field theories (EFTs) that can achieve a slow inflationary roll despite having a scalar potential that does not satisfy G{sup ab}∂{sub a}V∂{sub b}V≪V{sup 2}/M{sub p}{sup 2} (where G{sub ab} is the target-space metric). They evade the usual slow-roll conditions on V because their kinetic energies are dominated by single-derivative terms rather than the usual two-derivative terms. Single derivatives dominate during slow roll and so do not require a breakdown of the usual derivative expansion that underpins calculational control in much of cosmology. The presence of such terms requires some sort of UV Lorentz-symmetry breaking during inflation (besides the usual cosmological breaking). Chromo-natural inflation provides one particular example of a UV theory that can generate the multi-field single-derivative terms we consider, and we argue that the EFT we find indeed captures the slow-roll conditions for its background evolution. We also show that our EFT can be understood as a multi-field generalization of the single-field Cuscuton models. The multi-field case introduces a new feature, however: the scalar kinetic terms define a target-space 2-form, F{sub ab}, whose antisymmetry gives new ways for slow roll to be achieved.

  19. Magnon inflation: slow roll with steep potentials

    NASA Astrophysics Data System (ADS)

    Adshead, Peter; Blas, Diego; Burgess, C. P.; Hayman, Peter; Patil, Subodh P.

    2016-11-01

    We find multi-scalar effective field theories (EFTs) that can achieve a slow inflationary roll despite having a scalar potential that does not satisfy Script Gab ∂a V ∂b V ll V2/Mp2 (where Script Gab is the target-space metric). They evade the usual slow-roll conditions on V because their kinetic energies are dominated by single-derivative terms rather than the usual two-derivative terms. Single derivatives dominate during slow roll and so do not require a breakdown of the usual derivative expansion that underpins calculational control in much of cosmology. The presence of such terms requires some sort of UV Lorentz-symmetry breaking during inflation (besides the usual cosmological breaking). Chromo-natural inflation provides one particular example of a UV theory that can generate the multi-field single-derivative terms we consider, and we argue that the EFT we find indeed captures the slow-roll conditions for its background evolution. We also show that our EFT can be understood as a multi-field generalization of the single-field Cuscuton models. The multi-field case introduces a new feature, however: the scalar kinetic terms define a target-space 2-form, ℱab, whose antisymmetry gives new ways for slow roll to be achieved.

  20. Immunological detection of bean common mosaic virus in French bean (Phaseolus vulgaris L.) leaves.

    PubMed

    Verma, Poonam; Gupta, U P

    2010-09-01

    Bean common mosaic potyvirus (BCMV) is an important seed borne pathogen of French bean. Differential inoculation with bean common mosaic virus at cotylodonary trifoliate leaf stage and pre-flowering stage of crop growth revealed that cotyledonary leaf infection favored maximum disease expression. Under immunosorbent electron microscopy (ISEM) the virus particles of filamentous structure having a diameter of 750 nm (l) and 15 nm (w) were observed. These particles gave positive precipitin tests with polyclonal antiserum of Potato virus Y.

  1. A Roll, Fin, and Fin Controller Prediction Computer Program.

    DTIC Science & Technology

    1980-06-01

    Reference 1, and specific details of this improve- ment will be published in a future report currently under preparation by Cox. *A complete listing of...effects. CONCLUDING RMARKS This report provides a user’s guide to FINCON, a roll, fin, fin con- troller prediction computer program. No attempt to...180. FLOATIMUOIINU) ROLL I# OA14PUINUI a OUCIIV,1 ROLL 19 IF ( ITEPATE .EQ.0) O T3 98’ ROLL 106 Ise NTIY 0 ROLL lot To 0.0 ROLL lit s0 NTRY - NTYRY I

  2. Rolling Element Bearing Stiffness Matrix Determination (Presentation)

    SciTech Connect

    Guo, Y.; Parker, R.

    2014-01-01

    Current theoretical bearing models differ in their stiffness estimates because of different model assumptions. In this study, a finite element/contact mechanics model is developed for rolling element bearings with the focus of obtaining accurate bearing stiffness for a wide range of bearing types and parameters. A combined surface integral and finite element method is used to solve for the contact mechanics between the rolling elements and races. This model captures the time-dependent characteristics of the bearing contact due to the orbital motion of the rolling elements. A numerical method is developed to determine the full bearing stiffness matrix corresponding to two radial, one axial, and two angular coordinates; the rotation about the shaft axis is free by design. This proposed stiffness determination method is validated against experiments in the literature and compared to existing analytical models and widely used advanced computational methods. The fully-populated stiffness matrix demonstrates the coupling between bearing radial, axial, and tilting bearing deflections.

  3. Controlling roll perturbations in fruit flies

    PubMed Central

    Beatus, Tsevi; Guckenheimer, John M.; Cohen, Itai

    2015-01-01

    Owing to aerodynamic instabilities, stable flapping flight requires ever-present fast corrective actions. Here, we investigate how flies control perturbations along their body roll angle, which is unstable and their most sensitive degree of freedom. We glue a magnet to each fly and apply a short magnetic pulse that rolls it in mid-air. Fast video shows flies correct perturbations up to 100° within 30 ± 7 ms by applying a stroke-amplitude asymmetry that is well described by a linear proportional–integral controller. For more aggressive perturbations, we show evidence for nonlinear and hierarchical control mechanisms. Flies respond to roll perturbations within 5 ms, making this correction reflex one of the fastest in the animal kingdom. PMID:25762650

  4. Elimination of two viruses which interact synergistically from sweetpotato by shoot tip culture and cryotherapy.

    PubMed

    Wang, Q C; Valkonen, J P T

    2008-12-01

    Sweet potato chlorotic stunt virus (SPCSV; Closteroviridae) and Sweet potato feathery mottle virus (SPFMV; Potyviridae) interact synergistically and cause severe diseases in co-infected sweetpotato plants (Ipomoea batatas). Sweetpotato is propagated vegetatively and virus-free planting materials are pivotal for sustainable production. Using cryotherapy, SPCSV and SPCSV were eliminated from all treated single-virus-infected and co-infected shoot tips irrespective of size (0.5-1.5mm including 2-4 leaf primordia). While shoot tip culture also eliminated SPCSV, elimination of SPFMV failed in 90-93% of the largest shoot tips (1.5mm) using this technique. Virus distribution to different leaf primordia and tissues within leaf primordia in the shoot apex and petioles was not altered by co-infection of the viruses in the fully virus-susceptible sweetpotato genotype used. SPFMV was immunolocalized to all types of tissues and up to the fourth-youngest leaf primordium. In contrast, SPCSV was detected only in the phloem and up to the fifth leaf primordium. Because only cells in the apical dome of the meristem and the two first leaf primordia survived cryotherapy, all data taken together could explain the results of virus elimination. The simple and efficient cryotherapy protocol developed for virus elimination can also be used for preparation of sweetpotato materials for long-term preservation.

  5. Computer-aided roll pass design in rolling of airfoil shapes

    NASA Technical Reports Server (NTRS)

    Akgerman, N.; Lahoti, G. D.; Altan, T.

    1980-01-01

    This paper describes two computer-aided design (CAD) programs developed for modeling the shape rolling process for airfoil sections. The first program, SHPROL, uses a modular upper-bound method of analysis and predicts the lateral spread, elongation, and roll torque. The second program, ROLPAS, predicts the stresses, roll separating force, the roll torque and the details of metal flow by simulating the rolling process, using the slab method of analysis. ROLPAS is an interactive program; it offers graphic display capabilities and allows the user to interact with the computer via a keyboard, CRT, and a light pen. The accuracy of the computerized models was evaluated by (a) rolling a selected airfoil shape at room temperature from 1018 steel and isothermally at high temperature from Ti-6Al-4V, and (b) comparing the experimental results with computer predictions. The comparisons indicated that the CAD systems, described here, are useful for practical engineering purposes and can be utilized in roll pass design and analysis for airfoil and similar shapes.

  6. Routh symmetry in the Chaplygin's rolling ball

    NASA Astrophysics Data System (ADS)

    Kim, Byungsoo

    2011-12-01

    The Routh integral in the symmetric Chaplygin's rolling ball has been regarded as a mysterious conservation law due to its interesting form of sqrt {I_1 I_3 + m< {I_s ,s} rangle } Ω _3 . In this paper, a new form of the Routh integral is proposed as a Noether's pairing form of a conservation law. An explicit symmetry vector for the Routh integral is proved to associate the conserved quantity with the invariance of the Lagrangian function under the rollingly constrained nonholonomic variation. Then, the form of the Routh symmetry vector is discussed for its origin as the linear combination of the configurational vectors.

  7. Rolling friction on a granular medium

    NASA Astrophysics Data System (ADS)

    de Blasio, Fabio Vittorio; Saeter, May-Britt

    2009-02-01

    We present experimental results for the rolling of spheres on a granular bed. We use two sets of glass and steel spheres with varying diameters and a high-speed camera to follow the motion of the spheres. Despite the complex phenomena occurring during the rolling, the results show a friction coefficient nearly independent of the velocity (0.45-0.5 for glass and 0.6-0.65 for steel). It is found that for a given sphere density, the large spheres reach a longer distance, a result that may also help explain the rock sorting along natural stone accumulations at the foot of mountain slopes.

  8. Roll ring assemblies for the Space Station

    NASA Technical Reports Server (NTRS)

    Batista, J.; Vise, J.; Young, K.

    1994-01-01

    Space Station Freedom requires the transmission of high power and signals through three different rotational interfaces. Roll ring technology was baselined by NASA for rotary joints to transfer up to 65.5 kW of power for 30 years at greater than 99 percent efficiency. Signal transfer requirements included MIL-STD-1553 data transmission and 4.5 MHz RS250A base and color video. A unique design for each rotary joint was developed and tested to accomplish power and signal transfer. An overview of roll ring technology is presented, followed by design requirements, hardware configuration, and test results.

  9. Stress evaluations under rolling/sliding contacts

    NASA Technical Reports Server (NTRS)

    Kannel, J. W.; Tevaarwerk, J. L.

    1981-01-01

    The state of stress beneath traction drive type of contacts were analyzed. Computing stresses and stress reversals on various planes for points beneath the surface were examined. The effect of tangential and axial friction under gross slip conditions is evaluated with the models. Evaluations were performed on an RC (rolling contact) tester configuration and it is indicated that the classical fatigue stresses are not altered by friction forces typical of lubricated contact. Higher values of friction can result in surface shear reversal that exceeds the stresses at the depth of maximum shear reversal under rolling contact.

  10. Integrated aeroservoelastic synthesis for roll control

    NASA Technical Reports Server (NTRS)

    Nam, Chang-Ho; Weisshaar, Terrence A.

    1990-01-01

    The objective of this study is to illustrate an integrated, parallel design procedure for optimal structural, aerodynamic, and aileron synthesis of an aircraft wing. The effects of combining weight minimization with structural tailoring (ply orientation and thickness) of a lifting surface, together with the wing geometry (sweep angle and taper ratio), and the aileron geometry (spanwise location and chordwise size) upon the lateral control effectiveness are discussed. Several optimization studies for the minimization of aileron hinge moment and wing weight, subject to a specified constant aircraft roll rate at a design airspeed (roll effectiveness), are performed.

  11. Cross-directional interlocking of rolls in an air press of a papermaking machine

    DOEpatents

    Beck, David A.; Gorshe, Thomas

    2003-05-13

    An air press for pressing a paper web is composed of a plurality of rolls including at least a first roll and a second roll. The first roll and the second roll are positioned adjacent one another and form a first nip therebetween. Further, the first roll and the second roll each have a roll end, the roll end of the first roll adjoining the roll end of the second roll. A bevel plate is attached to the roll end of the first roll, the bevel plate having at least a first angled plate face. A seal ring is positioned adjacent the roll end of the second roll, the seal ring being juxtaposed to the bevel plate. The seal ring has at least a first angled ring face, and the first angled ring face mates with the first angled plate face.

  12. T Strip Properties Fabricated by Powder Rolling Method

    NASA Astrophysics Data System (ADS)

    Hong, Jae-Keun; Lee, Chae-Hun; Kim, Jeoung-Han; Yeom, Jong-Taek; Park, Nho-Kwang

    In the present study, the characteristics of the Ti powders fabricated by Hydride-Dehydride (HDH) were analyzed in terms of particle shape, size and size distribution. Ti powders were subjected to roll compaction and their microstructure and green densities were evaluated in terms of particle size, powder morphology, roll gap and rolling speed. Effects of blending elements having different powder sizes on densification properties were analyzed. The strip thickness was proportional to the roll gap up to 0.9 mm and the density of titanium strip was decreased with the increase in roll gap. As the roll speed increased, the strip density and thickness were decreased by using -200 mesh Ti powder. However, the effect of rolling speed for -400 mesh Ti powder was not greater than that of -200 mesh powder. The highest density by 93% was achieved by using -400 mesh Ti powder at 0.1 mm roll gap, however edge cracks and alligator cracks were occurred.

  13. Detail from roadbed showing sprocket teeth in rolling segment and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail from roadbed showing sprocket teeth in rolling segment and typical lateral bracing. View south - New York, New Haven & Hartford Railroad, Fort Point Channel Rolling Lift Bridge, Spanning Fort Point Channel, Boston, Suffolk County, MA

  14. Deep sequencing reveals a novel closterovirus associated with wild rose leaf rosette disease.

    PubMed

    He, Yan; Yang, Zuokun; Hong, Ni; Wang, Guoping; Ning, Guogui; Xu, Wenxing

    2015-06-01

    A bizarre virus-like symptom of a leaf rosette formed by dense small leaves on branches of wild roses (Rosa multiflora Thunb.), designated as 'wild rose leaf rosette disease' (WRLRD), was observed in China. To investigate the presumed causal virus, a wild rose sample affected by WRLRD was subjected to deep sequencing of small interfering RNAs (siRNAs) for a complete survey of the infecting viruses and viroids. The assembly of siRNAs led to the reconstruction of the complete genomes of three known viruses, namely Apple stem grooving virus (ASGV), Blackberry chlorotic ringspot virus (BCRV) and Prunus necrotic ringspot virus (PNRSV), and of a novel virus provisionally named 'rose leaf rosette-associated virus' (RLRaV). Phylogenetic analysis clearly placed RLRaV alongside members of the genus Closterovirus, family Closteroviridae. Genome organization of RLRaV RNA (17,653 nucleotides) showed 13 open reading frames (ORFs), except ORF1 and the quintuple gene block, most of which showed no significant similarities with known viral proteins, but, instead, had detectable identities to fungal or bacterial proteins. Additional novel molecular features indicated that RLRaV seems to be the most complex virus among the known genus members. To our knowledge, this is the first report of WRLRD and its associated closterovirus, as well as two ilarviruses and one capilovirus, infecting wild roses. Our findings present novel information about the closterovirus and the aetiology of this rose disease which should facilitate its control. More importantly, the novel features of RLRaV help to clarify the molecular and evolutionary features of the closterovirus.

  15. Leaf hydraulics II: vascularized tissues.

    PubMed

    Rockwell, Fulton E; Holbrook, N Michele; Stroock, Abraham D

    2014-01-07

    Current models of leaf hydration employ an Ohm's law analogy of the leaf as an ideal capacitor, neglecting the resistance to flow between cells, or treat the leaf as a plane sheet with a source of water at fixed potential filling the mid-plane, neglecting the discrete placement of veins as well as their resistance. We develop a model of leaf hydration that considers the average conductance of the vascular network to a representative areole (region bounded by the vascular network), and represent the volume of tissue within the areole as a poroelastic composite of cells and air spaces. Solutions to the 3D flow problem are found by numerical simulation, and these results are then compared to 1D models with exact solutions for a range of leaf geometries, based on a survey of temperate woody plants. We then show that the hydration times given by these solutions are well approximated by a sum of the ideal capacitor and plane sheet times, representing the time for transport through the vasculature and tissue respectively. We then develop scaling factors relating this approximate solution to the 3D model, and examine the dependence of these scaling factors on leaf geometry. Finally, we apply a similar strategy to reduce the dimensions of the steady state problem, in the context of peristomatal transpiration, and consider the relation of transpirational gradients to equilibrium leaf water potential measurements.

  16. A new begomovirus-betasatellite complex is associated with chilli leaf curl disease in Sri Lanka.

    PubMed

    Senanayake, D M J B; Jayasinghe, J E A R M; Shilpi, S; Wasala, S K; Mandal, Bikash

    2013-02-01

    Leaf curl disease of chilli (LCDC) is a major constraint in production of chilli in the Indian subcontinent. The objective of this study was to identify the begomovirus species occurring in chilli in Sri Lanka, where the LCDC was initially recorded in 1938. The virus samples were collected from the North Central Province, the major chilli growing region in Sri Lanka with a history of epidemic prevalence of LCDC. The virus could be readily transmitted by Bemisia tabaci to chilli, tomato and tobacco, where vein clearing followed by leaf curl developed. The genome analysis of two isolates obtained from two distantly located fields showing 100 % LCDC, revealed that the DNA-A genome (2754 nucleotides) shared 89.5 % sequence identity with each other and 68.80-84.40 % sequence identity with the other begomoviruses occurring in the Indian subcontinent. The closest identity (84.40 %) of the virus isolates was with Tomato leaf curl Sri Lanka virus (ToLCLKV). The results support that a new begomovirus species is affecting chilli in Sri Lanka and the name Chilli leaf curl Sri Lanka virus (ChiLCSLV) is proposed. Recombination analysis indicated that ChiLCSLV was a recombinant virus potentially originated from the begomoviruses prevailing in southern India and Sri Lanka. The genome of betasatellite associated with the two isolates consisted of 1366 and 1371 nucleotides and shared 95.2 % sequence identity with each other and 41.50-73.70 % sequence identity with the other betasatellite species. The results suggest that a new begomovirus betasatellite, Chilli leaf curl Sri Lanka betasatellite is associated with LCDC in Sri Lanka. This study demonstrates a new species of begomovirus and betasatellite complex is occurring in chilli in Sri Lanka and further shows that diverse begomovirus species are affecting chilli production in the Indian subcontinent.

  17. First report of Pepper mottle virus infecting tomato in Hawaii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In August 2011, tomato (Solanum lycopersicum L.) fruit from a University of Hawaii field trial evaluating varietal resistance to Tomato spotted wilt virus (TSWV) and Tomato yellow leaf curl virus (TYLCV) displayed mottling symptoms similar to that caused by TSWV or other tospoviruses. The foliage f...

  18. 46 CFR 28.575 - Severe wind and roll.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Severe wind and roll. 28.575 Section 28.575 Shipping... INDUSTRY VESSELS Stability § 28.575 Severe wind and roll. (a) Each vessel must meet paragraphs (f) and (g) of this section when subjected to the gust wind heeling arm and the angle of roll to windward...

  19. 46 CFR 28.575 - Severe wind and roll.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Severe wind and roll. 28.575 Section 28.575 Shipping... INDUSTRY VESSELS Stability § 28.575 Severe wind and roll. (a) Each vessel must meet paragraphs (f) and (g) of this section when subjected to the gust wind heeling arm and the angle of roll to windward...

  20. Conceptualizing Rolling Motion Through an Extreme Case Reasoning Approach

    NASA Astrophysics Data System (ADS)

    Hasović, Elvedin; Mešić, Vanes; Erceg, Nataša

    2017-03-01

    In this paper we are going to show how learning about some counterintuitive aspects of rolling motion can be facilitated by combining the use of analogies with extreme case reasoning. Specifically, the intuitively comprehensible examples of "rolling" polygonal prisms are used as an analogical anchor that is supposed to help the students develop conceptual understanding about counterintuitive aspects of rolling motion.

  1. 15. VIEW OF ROLLING OPERATION. INGOTS AND BAR STOCK WERE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. VIEW OF ROLLING OPERATION. INGOTS AND BAR STOCK WERE ROLLED TO A SPECIFIED THICKNESS IN PREPARATION FOR FURTHER PROCESSING. (11/82) - Rocky Flats Plant, Uranium Rolling & Forming Operations, Southeast section of plant, southeast quadrant of intersection of Central Avenue & Eighth Street, Golden, Jefferson County, CO

  2. 25 CFR 75.15 - Current membership roll.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Current membership roll. 75.15 Section 75.15 Indians... THE EASTERN BAND OF CHEROKEE INDIANS, NORTH CAROLINA § 75.15 Current membership roll. The membership roll of the Eastern Band of Cherokee Indians shall be kept current by striking therefrom the names...

  3. 21 CFR 136.130 - Milk bread, rolls, and buns.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., buttermilk product, cheese whey, cheese whey product, or milk protein is used. (b) The name of the food is... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Milk bread, rolls, and buns. 136.130 Section 136....130 Milk bread, rolls, and buns. (a) Each of the foods milk bread, milk rolls, and milk buns...

  4. 25 CFR 75.15 - Current membership roll.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Current membership roll. 75.15 Section 75.15 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR TRIBAL GOVERNMENT REVISION OF THE MEMBERSHIP ROLL OF THE EASTERN BAND OF CHEROKEE INDIANS, NORTH CAROLINA § 75.15 Current membership roll. The...

  5. 25 CFR 75.4 - Basic membership roll.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Basic membership roll. 75.4 Section 75.4 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR TRIBAL GOVERNMENT REVISION OF THE MEMBERSHIP ROLL OF THE EASTERN BAND OF CHEROKEE INDIANS, NORTH CAROLINA § 75.4 Basic membership roll. All persons...

  6. 25 CFR 75.15 - Current membership roll.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Current membership roll. 75.15 Section 75.15 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR TRIBAL GOVERNMENT REVISION OF THE MEMBERSHIP ROLL OF THE EASTERN BAND OF CHEROKEE INDIANS, NORTH CAROLINA § 75.15 Current membership roll. The...

  7. 25 CFR 75.4 - Basic membership roll.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Basic membership roll. 75.4 Section 75.4 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR TRIBAL GOVERNMENT REVISION OF THE MEMBERSHIP ROLL OF THE EASTERN BAND OF CHEROKEE INDIANS, NORTH CAROLINA § 75.4 Basic membership roll. All persons whose...

  8. 25 CFR 75.4 - Basic membership roll.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Basic membership roll. 75.4 Section 75.4 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR TRIBAL GOVERNMENT REVISION OF THE MEMBERSHIP ROLL OF THE EASTERN BAND OF CHEROKEE INDIANS, NORTH CAROLINA § 75.4 Basic membership roll. All persons...

  9. 25 CFR 75.4 - Basic membership roll.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Basic membership roll. 75.4 Section 75.4 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR TRIBAL GOVERNMENT REVISION OF THE MEMBERSHIP ROLL OF THE EASTERN BAND OF CHEROKEE INDIANS, NORTH CAROLINA § 75.4 Basic membership roll. All persons...

  10. 25 CFR 75.15 - Current membership roll.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Current membership roll. 75.15 Section 75.15 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR TRIBAL GOVERNMENT REVISION OF THE MEMBERSHIP ROLL OF THE EASTERN BAND OF CHEROKEE INDIANS, NORTH CAROLINA § 75.15 Current membership roll. The...

  11. 46 CFR 56.30-15 - Expanded or rolled joints.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Expanded or rolled joints. 56.30-15 Section 56.30-15... APPURTENANCES Selection and Limitations of Piping Joints § 56.30-15 Expanded or rolled joints. (a) Expanded or rolled joints may be used where experience or test has demonstrated that the joint is suitable for...

  12. 46 CFR 56.30-15 - Expanded or rolled joints.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Expanded or rolled joints. 56.30-15 Section 56.30-15... APPURTENANCES Selection and Limitations of Piping Joints § 56.30-15 Expanded or rolled joints. (a) Expanded or rolled joints may be used where experience or test has demonstrated that the joint is suitable for...

  13. 46 CFR 56.30-15 - Expanded or rolled joints.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Expanded or rolled joints. 56.30-15 Section 56.30-15... APPURTENANCES Selection and Limitations of Piping Joints § 56.30-15 Expanded or rolled joints. (a) Expanded or rolled joints may be used where experience or test has demonstrated that the joint is suitable for...

  14. 46 CFR 56.30-15 - Expanded or rolled joints.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Expanded or rolled joints. 56.30-15 Section 56.30-15... APPURTENANCES Selection and Limitations of Piping Joints § 56.30-15 Expanded or rolled joints. (a) Expanded or rolled joints may be used where experience or test has demonstrated that the joint is suitable for...

  15. 46 CFR 56.30-15 - Expanded or rolled joints.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Expanded or rolled joints. 56.30-15 Section 56.30-15... APPURTENANCES Selection and Limitations of Piping Joints § 56.30-15 Expanded or rolled joints. (a) Expanded or rolled joints may be used where experience or test has demonstrated that the joint is suitable for...

  16. 14. VIEW OF METAL ROLLING OPERATION. THE METALS ARE BEING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. VIEW OF METAL ROLLING OPERATION. THE METALS ARE BEING PREPARED TO BE ROLLED INTO SHEETS OF SPECIFIC THICKNESS. COMPONENT PARTS WERE FABRICATED FROM THE METAL SHEETS. (11/82) - Rocky Flats Plant, Uranium Rolling & Forming Operations, Southeast section of plant, southeast quadrant of intersection of Central Avenue & Eighth Street, Golden, Jefferson County, CO

  17. 21 CFR 136.130 - Milk bread, rolls, and buns.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., buttermilk product, cheese whey, cheese whey product, or milk protein is used. (b) The name of the food is... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Milk bread, rolls, and buns. 136.130 Section 136....130 Milk bread, rolls, and buns. (a) Each of the foods milk bread, milk rolls, and milk buns...

  18. 21 CFR 136.130 - Milk bread, rolls, and buns.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., buttermilk product, cheese whey, cheese whey product, or milk protein is used. (b) The name of the food is... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Milk bread, rolls, and buns. 136.130 Section 136....130 Milk bread, rolls, and buns. (a) Each of the foods milk bread, milk rolls, and milk buns...

  19. 21 CFR 136.130 - Milk bread, rolls, and buns.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., buttermilk product, cheese whey, cheese whey product, or milk protein is used. (b) The name of the food is... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Milk bread, rolls, and buns. 136.130 Section 136....130 Milk bread, rolls, and buns. (a) Each of the foods milk bread, milk rolls, and milk buns...

  20. 21 CFR 136.130 - Milk bread, rolls, and buns.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., buttermilk product, cheese whey, cheese whey product, or milk protein is used. (b) The name of the food is... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Milk bread, rolls, and buns. 136.130 Section 136....130 Milk bread, rolls, and buns. (a) Each of the foods milk bread, milk rolls, and milk buns...

  1. Archips xylosteana (L.) (Lepidoptera: Tortricidae), a Palearctic leaf-rolling moth, new to North America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Archips xylosteana (L.), a widespread Palearctic tortricid moth, is reported from St. John’s, Newfoundland, the first confirmed records of this species in North America. Adults were collected by beating branches and foliage of a variety of ornamental trees and shrubs on the campus of Memorial Univer...

  2. Leaf Relative Water Content Estimated from Leaf Reflectance and Transmittance

    NASA Technical Reports Server (NTRS)

    Vanderbilt, Vern; Daughtry, Craig; Dahlgren, Robert

    2016-01-01

    Remotely sensing the water status of plants and the water content of canopies remain long term goals of remote sensing research. In the research we report here, we used optical polarization techniques to monitor the light reflected from the leaf interior, R, as well as the leaf transmittance, T, as the relative water content (RWC) of corn (Zea mays) leaves decreased. Our results show that R and T both change nonlinearly. The result show that the nonlinearities cancel in the ratio R/T, which appears linearly related to RWC for RWC less than 90%. The results suggest that potentially leaf water status and perhaps even canopy water status could be monitored starting from leaf and canopy optical measurements.

  3. Discrete particle modelling of granular roll waves

    NASA Astrophysics Data System (ADS)

    Tsang, Jonathan; Dalziel, Stuart; Vriend, Nathalie

    2016-11-01

    A granular current flowing down an inclined chute or plane can undergo an instability that leads to the formation of surface waves, known as roll waves. Examples of roll waves are found in avalanches and debris flows in landslides, and in many industrial processes. Although related to the Kapitza instability of viscous fluid films, granular roll waves are not yet as well understood. Laboratory experiments typically measure the surface height and velocity of a current as functions of position and time, but they do not give insight into the processes below the surface: in particular, the possible formation of a boundary layer at the free surface as well as the base. To overcome this, we are running discrete particle model (DPM) simulations. Simulations are validated against our laboratory experiments, but they also allow us to examine a much larger range of parameters, such as material properties, chute geometry and particle size dispersity, than that which is possible in the lab. We shall present results from simulations in which we vary particle size and dispersity, and examine the implications on roll wave formation and propagation. Future work will include simulations in which the shape of the chute is varied, both cross-sectionally and in the downstream direction. EPSRC studentship (Tsang) and Royal Society Research Fellowship (Vriend).

  4. Malaria. Can WHO roll back malaria?

    PubMed

    Balter, M

    2000-10-20

    In October 1998, World Health Organization Director-General Gro Harlem Brundtland announced Roll Back Malaria, a multiagency crusade that aims to cut malaria mortality in half over the next 10 years. Brundtland might just be the one to pull it off, say numerous public health experts, although some researchers question whether the goal is realistic.

  5. 9 CFR 381.159 - Poultry rolls.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Poultry rolls. 381.159 Section 381.159... ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION POULTRY PRODUCTS INSPECTION REGULATIONS Definitions and Standards of Identity or Composition §...

  6. 9 CFR 381.159 - Poultry rolls.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Poultry rolls. 381.159 Section 381.159... ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION POULTRY PRODUCTS INSPECTION REGULATIONS Definitions and Standards of Identity or Composition §...

  7. 9 CFR 381.159 - Poultry rolls.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Poultry rolls. 381.159 Section 381.159... ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION POULTRY PRODUCTS INSPECTION REGULATIONS Definitions and Standards of Identity or Composition §...

  8. 9 CFR 381.159 - Poultry rolls.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Poultry rolls. 381.159 Section 381.159... ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION POULTRY PRODUCTS INSPECTION REGULATIONS Definitions and Standards of Identity or Composition §...

  9. 9 CFR 381.159 - Poultry rolls.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Poultry rolls. 381.159 Section 381.159... ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION POULTRY PRODUCTS INSPECTION REGULATIONS Definitions and Standards of Identity or Composition §...

  10. Land rolling increases broadleaf weed emergence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the northern Great Plains, annual forage and pulse crops typically are land rolled after planting to push rocks back into the soil to prevent damage to harvest equipment. Packer wheels commonly are used at planting to improve soil-seed contact for more uniform crop emergence and subsequent matur...

  11. Tool For Robotic Resistive Roll Welding

    NASA Technical Reports Server (NTRS)

    Gilber, Jeffrey L.

    1991-01-01

    Roll-welding attachment for robot simple, inexpensive device incorporating modified commercial resistance-welding gun. Modified welding gun easily attaches to end effector of robot. Robot applies welding force and moves electrode wheel along prescribed path. Resistance-welding current starts and stops automatically according to force exerted against workpiece. Used to apply brazing foil to workpiece.

  12. 14 CFR 23.349 - Rolling conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Rolling conditions. The wing and wing bracing must be designed for the following loading conditions: (a) Unsymmetrical wing loads appropriate to the category. Unless the following values result in unrealistic loads... semispan wing airload acts on one side of the plane of symmetry and 60 percent of this load acts on...

  13. 14 CFR 23.349 - Rolling conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Rolling conditions. The wing and wing bracing must be designed for the following loading conditions: (a) Unsymmetrical wing loads appropriate to the category. Unless the following values result in unrealistic loads... semispan wing airload acts on one side of the plane of symmetry and 60 percent of this load acts on...

  14. 14 CFR 23.349 - Rolling conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Rolling conditions. The wing and wing bracing must be designed for the following loading conditions: (a) Unsymmetrical wing loads appropriate to the category. Unless the following values result in unrealistic loads... semispan wing airload acts on one side of the plane of symmetry and 60 percent of this load acts on...

  15. 14 CFR 23.349 - Rolling conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Rolling conditions. The wing and wing bracing must be designed for the following loading conditions: (a) Unsymmetrical wing loads appropriate to the category. Unless the following values result in unrealistic loads... semispan wing airload acts on one side of the plane of symmetry and 60 percent of this load acts on...

  16. 14 CFR 23.349 - Rolling conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Rolling conditions. The wing and wing bracing must be designed for the following loading conditions: (a) Unsymmetrical wing loads appropriate to the category. Unless the following values result in unrealistic loads... semispan wing airload acts on one side of the plane of symmetry and 60 percent of this load acts on...

  17. Rolling Friction on a Wheeled Laboratory Cart

    ERIC Educational Resources Information Center

    Mungan, Carl E.

    2012-01-01

    A simple model is developed that predicts the coefficient of rolling friction for an undriven laboratory cart on a track that is approximately independent of the mass loaded onto the cart and of the angle of inclination of the track. The model includes both deformation of the wheels/track and frictional torque at the axles/bearings. The concept of…

  18. Large Scale Evaluation fo Nickel Aluminide Rolls

    SciTech Connect

    2005-09-01

    This completed project was a joint effort between Oak Ridge National Laboratory and Bethlehem Steel (now Mittal Steel) to demonstrate the effectiveness of using nickel aluminide intermetallic alloy rolls as part of an updated, energy-efficient, commercial annealing furnace system.

  19. Oscillations and Rolling for Duffing's Equation

    NASA Astrophysics Data System (ADS)

    Aref'eva, I. Ya.; Piskovskiy, E. V.; Volovich, I. V.

    2013-01-01

    The Duffing equation has been used to model nonlinear dynamics not only in mechanics and electronics but also in biology and in neurology for the brain process modeling. Van der Pol's method is often used in nonlinear dynamics to improve perturbation theory results when describing small oscillations. However, in some other problems of nonlinear dynamics particularly in case of Duffing-Higgs equation in field theory, for the Einsten-Friedmann equations in cosmology and for relaxation processes in neurology not only small oscillations regime is of interest but also the regime of slow rolling. In the present work a method for approximate solution to nonlinear dynamics equations in the rolling regime is developed. It is shown that in order to improve perturbation theory in the rolling regime it turns out to be effective to use an expansion in hyperbolic functions instead of trigonometric functions as it is done in van der Pol's method in case of small oscillations. In particular the Duffing equation in the rolling regime is investigated using solution expressed in terms of elliptic functions. Accuracy of obtained approximation is estimated. The Duffing equation with dissipation is also considered.

  20. Antares Rolls Out to Wallops Launch Pad

    NASA Video Gallery

    Orbital Sciences Corporation’s Antares rocket rolls out to the launch pad at NASA’s Wallops Flight Facility on the morning of Oct. 1, 2012. Over the next several months, Orbital plans a hot-fir...

  1. Development of a Rolling Process Design Tool for Use in Improving Hot Roll Slab Recovery

    SciTech Connect

    Couch, R; Becker, R; Rhee, M; Li, M

    2004-09-24

    Lawrence Livermore National Laboratory participated in a U. S. Department of Energy/Office of Industrial Technology sponsored research project 'Development of a Rolling Process Design Tool for Use in Improving Hot Roll Slab Recovery', as a Cooperative Agreement TC-02028 with the Alcoa Technical Center (ATC). The objective of the joint project with Alcoa is to develop a numerical modeling capability to optimize the hot rolling process used to produce aluminum plate. Product lost in the rolling process and subsequent recycling, wastes resources consumed in the energy-intensive steps of remelting and reprocessing the ingot. The modeling capability developed by project partners will be used to produce plate more efficiently and with reduced product loss.

  2. Conical Euler analysis and active roll suppression for unsteady vortical flows about rolling delta wings

    NASA Technical Reports Server (NTRS)

    Lee-Rausch, Elizabeth M.; Batina, John T.

    1993-01-01

    A conical Euler code was developed to study unsteady vortex-dominated flows about rolling, highly swept delta wings undergoing either forced motions or free-to-roll motions that include active roll suppression. The flow solver of the code involves a multistage, Runge-Kutta time-stepping scheme that uses a cell-centered, finite-volume, spatial discretization of the Euler equations on an unstructured grid of triangles. The code allows for the additional analysis of the free to-roll case by simultaneously integrating in time the rigid-body equation of motion with the governing flow equations. Results are presented for a delta wing with a 75 deg swept, sharp leading edge at a free-stream Mach number of 1.2 and at 10 deg, 20 deg, and 30 deg angle of attack alpha. At the lower angles of attack (10 and 20 deg), forced-harmonic analyses indicate that the rolling-moment coefficients provide a positive damping, which is verified by free-to-roll calculations. In contrast, at the higher angle of attack (30 deg), a forced-harmonic analysis indicates that the rolling-moment coefficient provides negative damping at the small roll amplitudes. A free-to-roll calculation for this case produces an initially divergent response, but as the amplitude of motion grows with time, the response transitions to a wing-rock type of limit cycle oscillation, which is characteristic of highly swept delta wings. This limit cycle oscillation may be actively suppressed through the use of a rate-feedback control law and antisymmetrically deflected leading-edge flaps. Descriptions of the conical Euler flow solver and the free-to roll analysis are included in this report. Results are presented that demonstrate how the systematic analysis of the forced response of the delta wing can be used to predict the stable, neutrally stable, and unstable free response of the delta wing. These results also give insight into the flow physics associated with unsteady vortical flows about delta wings undergoing forced

  3. Raspberry latent virus, a New Reovirus Isolated from Crumbly Fruited Red Raspberry Plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A virus induced crumbly fruit disease in 'Meeker' and other red raspberry cultivars has been observed in northern Washington, USA and British Columbia, Canada. Raspberry bushy dwarf virus (RBDV) and Raspberry leaf mottle virus (RLMV) were detected in raspberries with severe crumbly fruit. In additi...

  4. Patterns of Virus Distribution in Single and Mixed Infections of Florida Watermelons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whitefly-transmitted Squash vein yellowing virus (SqVYV) and Cucurbit leaf crumple virus (CuLCrV), and aphid-transmitted Papaya ringspot virus type W (PRSV-W) have had serious impact on watermelon production in southwest and west-central Florida in recent years. To determine the distribution of vir...

  5. Patterns of Virus Distribution in Single and Mixed Infections of Florida Watermelons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whitefly-transmitted Squash vein yellowing virus (SqVYV) and Cucurbit leaf crumple virus (CuLCrV), and aphid-transmitted Papaya ringspot virus type W (PRSV-W) have had serious impact on watermelon production in southwest and west-central Florida in recent years. Tissue blot nucleic acid hybridizati...

  6. [Identification of plant viruses infecting transgenic potatoes resistant to the Colorado beetle].

    PubMed

    Mel'nychuk, M D; Spyrydonov, V G

    2001-01-01

    Virus tolerance of the three varieties of Bt-potato New Leaf--Atlantic, Russet Burbank and Superior from "Monsanto company" has been studied. Using serology, biochemistry methods and biotest the mixed virus infecting of experimental plants has been shown. Virus transmission by infected potato root crops under reproduction and accelerated degradation processes during storage have been registered.

  7. Distribution of Four Viruses in Single and Mixed Infections Within Infected Watermelon Plants in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whitefly-transmitted Squash vein yellowing virus (SqVYV) and Cucurbit leaf crumple virus (CuLCrV), and aphid-transmitted Papaya ringspot virus type W (PRSV-W) have had serious impact on watermelon production in southwest and west-central Florida in recent years. Tissue blot nucleic acid hybridizati...

  8. Laser direct write system for fabricating seamless roll-to-roll lithography tools

    NASA Astrophysics Data System (ADS)

    Petrzelka, Joseph E.; Hardt, David E.

    2013-03-01

    Implementations of roll to roll contact lithography require new approaches towards manufacturing tooling, including stamps for roll to roll nanoimprint lithography (NIL) and soft lithography. Suitable roll based tools must have seamless micro- or nano-scale patterns and must be scalable to roll widths of one meter. The authors have developed a new centrifugal stamp casting process that can produce uniform cylindrical polymer stamps in a scalable manner. The pattern on the resulting polymer tool is replicated against a corresponding master pattern on the inner diameter of a centrifuge drum. This master pattern is created in photoresist using a UV laser direct write system. This paper discusses the design and implementation of a laser direct write system targeting the internal diameter of a rotating drum. The design uses flying optics to focus a laser beam along the axis of the centrifuge drum and to redirect the beam towards the drum surface. Experimental patterning results show uniform coatings of negative photoresist in the centrifuge drum that are effectively patterned with a 405 nm laser diode. Seamless patterns are shown to be replicated in a 50 mm diameter, 60 mm long cylindrical stamp made from polydimethylsiloxane (PDMS). Direct write results show gratings with line widths of 10 microns in negative photoresist. Using an FPGA, the laser can be accurately timed against the centrifuge encoder to create complex patterns.

  9. Roll-to-Roll Nanomanufacturing of Hybrid Nanostructures for Energy Storage Device Design.

    PubMed

    Oakes, Landon; Hanken, Trevor; Carter, Rachel; Yates, William; Pint, Cary L

    2015-07-08

    A key limitation to the practical incorporation of nanostructured materials into emerging applications is the challenge of achieving low-cost, high throughput, and highly replicable scalable nanomanufacturing techniques to produce functional materials. Here, we report a benchtop roll-to-roll technique that builds upon the use of binary solutions of nanomaterials and liquid electrophoretic assembly to rapidly construct hybrid materials for battery design applications. We demonstrate surfactant-free hybrid mixtures of carbon nanotubes, silicon nanoparticles, MoS2 nanosheets, carbon nanohorns, and graphene nanoplatelets. Roll-to-roll electrophoretic assembly from these solutions enables the controlled fabrication of homogeneous coatings of these nanostructures that maintain chemical and physical properties defined by the synergistic combination of nanomaterials utilized without adverse effects of surfactants or impurities that typically limit liquid nanomanufacturing routes. To demonstrate the utility of this nanomanufacturing approach, we employed roll-to-roll electrophoretic processing to fabricate both positive and negative electrodes for lithium ion batteries in less than 30 s. The optimized full-cell battery, containing active materials of prelithiated silicon nanoparticles and MoS2 nanosheets, was assessed to exhibit energy densities of 167 Wh/kgcell(-1) and power densities of 9.6 kW/kgcell(-1).

  10. Roll-to-roll embossing of optical linear Fresnel lens polymer film for solar concentration.

    PubMed

    Zhang, XinQuan; Liu, Kui; Shan, Xuechuan; Liu, Yuchan

    2014-12-15

    Roll-to-roll manufacturing has been proven to be a high-throughput and low-cost technology for continuous fabrication of functional optical polymer films. In this paper, we have firstly studied a complete manufacturing cycle of linear Fresnel lens polymer film for solar concentration in the aspects of ultra-precision diamond machining of metal roller mold, roll-to-roll embossing, and measurement on film profile and functionality. A metal roller mold patterned with linear Fresnel lenses is obtained using single point diamond turning technique. The roller mold is installed onto a self-developed roll-to-roll UV embossing system to realize continuous manufacturing of linear Fresnel lens film. Profile measurement of the machined roller mold and the embossed polymer film, which is conducted using a stylus profilometer, shows good agreement between measured facet angles with designed ones. Functionality test is conducted on a solar simulation system with a reference solar cell, and results show that strong light concentration is realized.

  11. High resolution patterning for flexible electronics via roll-to-roll nanoimprint lithography

    NASA Astrophysics Data System (ADS)

    Sabik, Sami; de Riet, Joris; Yakimets, Iryna; Smits, Edsger

    2014-03-01

    Flexible electronics is a growing field and is currently maturing in applications such as displays, smart packaging, organic light-emitting diodes and organic photovoltaic cells. In order to process on flexible substrates at high throughput and large areas, novel patterning techniques will be essential. Conventional optical lithography is limited in throughput as well as resolution, and requires several alignment steps to generate multi-layered patterns, required for applications such as thin-film transistors. It therefore remains a complex and expensive process. Nanoimprint lithography is an emerging alternative to optical lithography, demonstrating patterning capabilities over a wide range of resolutions, from several microns down to a few nanometres. For display applications, nanoimprint lithography can be used to pattern various layers. Micron sized thin-film transistors for backplane can be fabricated where a self-aligned geometry is used to decrease the number of alignment steps, and increase the overlay accuracy. In addition, nano-structures can be used for optical applications such as anti-reflective surfaces and nano patterned transparent electrodes. Imprint lithography is a fully roll-to-roll compatible process and enables large area and high throughput fabrication for flexible electronics. In this paper we discuss the possibilities and the challenges of large area patterning by roll-to-roll nanoimprint lithography, reviewing micron and nano sized structures realized on our roll-to-roll equipment. Nano patterned transparent electrodes, moth-eye antireflective coatings, and multilevel structures will be covered.

  12. Diffuse and specular characteristics of leaf reflectance

    NASA Technical Reports Server (NTRS)

    Grant, Lois

    1987-01-01

    In this paper, the evolution of current understanding of the mechanisms of leaf reflectance is reviewed. The use of measurements of polarized reflectance to separate leaf reflectance into diffuse and specular components is discussed. A section on the factors influencing leaf reflectance - leaf structure and physiological disturbances - is included along with discussion on the manner in which these influences are manifested.

  13. 7 CFR 29.3036 - Leaf surface.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf surface. 29.3036 Section 29.3036 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Leaf surface. The smoothness or roughness of the web or lamina of a tobacco leaf. Leaf surface...

  14. Near infrared leaf reflectance modeling

    NASA Technical Reports Server (NTRS)

    Parrish, J. B.

    1985-01-01

    Near infrared leaf reflectance modeling using Fresnel's equation (Kumar and Silva, 1973) and Snell's Law successfully approximated the spectral curve for a 0.25-mm turgid oak leaf lying on a Halon background. Calculations were made for ten interfaces, air-wax, wax-cellulose, cellulose-water, cellulose-air, air-water, and their inverses. A water path of 0.5 mm yielded acceptable results, and it was found that assignment of more weight to those interfaces involving air versus water or cellulose, and less to those involving wax, decreased the standard deviation of the error for all wavelengths. Data suggest that the air-cell interface is not the only important contributor to the overall reflectance of a leaf. Results also argue against the assertion that the near infrared plateau is a function of cell structure within the leaf.

  15. Experiments in Whole Leaf Photosynthesis

    ERIC Educational Resources Information Center

    Stewart, J. C.; And Others

    1974-01-01

    Described is a simple experimental system, which uses radioactive carbon dioxide to study whole leaf photosynthesis under a variety of conditions. Other experiments and simple apparatus for the experiments are also described. (Author/RH)

  16. 76 FR 36081 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil and Japan: Revocation of the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-21

    ... International Trade Administration Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil and Japan... reviews of the antidumping duty (``AD'') orders on certain hot-rolled flat-rolled carbon-quality steel products (``hot-rolled steel'') from Brazil and Japan, and on December 3, 2010, the final results of...

  17. ECHO virus

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/001340.htm ECHO virus To use the sharing features on this page, please enable JavaScript. Enteric cytopathic human orphan (ECHO) viruses are a group of viruses that lead to ...

  18. Why do leaf-tying caterpillars abandon their leaf ties?

    PubMed Central

    Sliwinski, Michelle

    2013-01-01

    Leaf-tying caterpillars act as ecosystem engineers by building shelters between overlapping leaves, which are inhabited by other arthropods. Leaf-tiers have been observed to leave their ties and create new shelters (and thus additional microhabitats), but the ecological factors affecting shelter fidelity are poorly known. For this study, we explored the effects of resource limitation and occupant density on shelter fidelity and assessed the consequences of shelter abandonment. We first quantified the area of leaf material required for a caterpillar to fully develop for two of the most common leaf-tiers that feed on white oak, Quercus alba. On average, Psilocorsis spp. caterpillars consumed 21.65 ± 0.67 cm2 leaf material to complete development. We also measured the area of natural leaf ties found in a Maryland forest, to determine the distribution of resources available to caterpillars in situ. Of 158 natural leaf ties examined, 47% were too small to sustain an average Psilocorsis spp. caterpillar for the entirety of its development. We also manipulated caterpillar densities within experimental ties on potted trees to determine the effects of cohabitants on the likelihood of a caterpillar to leave its tie. We placed 1, 2, or 4 caterpillars in ties of a standard size and monitored the caterpillars twice daily to track their movement. In ties with more than one occupant, caterpillars showed a significantly greater propensity to leave their tie, and left sooner and at a faster rate than those in ties as single occupants. To understand the consequences of leaf tie abandonment, we observed caterpillars searching a tree for a site to build a shelter in the field. This is a risky behavior, as 17% of the caterpillars observed died while searching for a shelter site. Caterpillars that successfully built a shelter traveled 110 ± 20 cm and took 28 ± 7 min to find a suitable site to build a shelter. In conclusion, leaf-tying caterpillars must frequently abandon their leaf

  19. Why do leaf-tying caterpillars abandon their leaf ties?

    PubMed

    Sliwinski, Michelle; Sigmon, Elisha

    2013-01-01

    Leaf-tying caterpillars act as ecosystem engineers by building shelters between overlapping leaves, which are inhabited by other arthropods. Leaf-tiers have been observed to leave their ties and create new shelters (and thus additional microhabitats), but the ecological factors affecting shelter fidelity are poorly known. For this study, we explored the effects of resource limitation and occupant density on shelter fidelity and assessed the consequences of shelter abandonment. We first quantified the area of leaf material required for a caterpillar to fully develop for two of the most common leaf-tiers that feed on white oak, Quercus alba. On average, Psilocorsis spp. caterpillars consumed 21.65 ± 0.67 cm(2) leaf material to complete development. We also measured the area of natural leaf ties found in a Maryland forest, to determine the distribution of resources available to caterpillars in situ. Of 158 natural leaf ties examined, 47% were too small to sustain an average Psilocorsis spp. caterpillar for the entirety of its development. We also manipulated caterpillar densities within experimental ties on potted trees to determine the effects of cohabitants on the likelihood of a caterpillar to leave its tie. We placed 1, 2, or 4 caterpillars in ties of a standard size and monitored the caterpillars twice daily to track their movement. In ties with more than one occupant, caterpillars showed a significantly greater propensity to leave their tie, and left sooner and at a faster rate than those in ties as single occupants. To understand the consequences of leaf tie abandonment, we observed caterpillars searching a tree for a site to build a shelter in the field. This is a risky behavior, as 17% of the caterpillars observed died while searching for a shelter site. Caterpillars that successfully built a shelter traveled 110 ± 20 cm and took 28 ± 7 min to find a suitable site to build a shelter. In conclusion, leaf-tying caterpillars must frequently abandon their leaf

  20. Static measurements of slender delta wing rolling moment hysteresis

    NASA Technical Reports Server (NTRS)

    Katz, Joseph; Levin, Daniel

    1991-01-01

    Slender delta wing planforms are susceptible to self-induced roll oscillations due to aerodynamic hysteresis during the limit cycle roll oscillation. Test results are presented which clearly establish that the static rolling moment hysteresis has a damping character; hysteresis tends to be greater when, due to either wing roll or side slip, the vortex burst moves back and forth over the wing trailing edge. These data are an indirect indication of the damping role of the vortex burst during limit cycle roll oscillations.

  1. Increasing leaf hydraulic conductance with transpiration rate minimizes the water potential drawdown from stem to leaf

    PubMed Central

    Simonin, Kevin A.; Burns, Emily; Choat, Brendan; Barbour, Margaret M.; Dawson, Todd E.; Franks, Peter J.

    2015-01-01

    Leaf hydraulic conductance (k leaf) is a central element in the regulation of leaf water balance but the properties of k leaf remain uncertain. Here, the evidence for the following two models for k leaf in well-hydrated plants is evaluated: (i) k leaf is constant or (ii) k leaf increases as transpiration rate (E) increases. The difference between stem and leaf water potential (ΔΨstem–leaf), stomatal conductance (g s), k leaf, and E over a diurnal cycle for three angiosperm and gymnosperm tree species growing in a common garden, and for Helianthus annuus plants grown under sub-ambient, ambient, and elevated atmospheric CO2 concentration were evaluated. Results show that for well-watered plants k leaf is positively dependent on E. Here, this property is termed the dynamic conductance, k leaf(E), which incorporates the inherent k leaf at zero E, which is distinguished as the static conductance, k leaf(0). Growth under different CO2 concentrations maintained the same relationship between k leaf and E, resulting in similar k leaf(0), while operating along different regions of the curve owing to the influence of CO2 on g s. The positive relationship between k leaf and E minimized variation in ΔΨstem–leaf. This enables leaves to minimize variation in Ψleaf and maximize g s and CO2 assimilation rate over the diurnal course of evaporative demand. PMID:25547915

  2. Increasing leaf hydraulic conductance with transpiration rate minimizes the water potential drawdown from stem to leaf.

    PubMed

    Simonin, Kevin A; Burns, Emily; Choat, Brendan; Barbour, Margaret M; Dawson, Todd E; Franks, Peter J

    2015-03-01

    Leaf hydraulic conductance (k leaf) is a central element in the regulation of leaf water balance but the properties of k leaf remain uncertain. Here, the evidence for the following two models for k leaf in well-hydrated plants is evaluated: (i) k leaf is constant or (ii) k leaf increases as transpiration rate (E) increases. The difference between stem and leaf water potential (ΔΨstem-leaf), stomatal conductance (g s), k leaf, and E over a diurnal cycle for three angiosperm and gymnosperm tree species growing in a common garden, and for Helianthus annuus plants grown under sub-ambient, ambient, and elevated atmospheric CO₂ concentration were evaluated. Results show that for well-watered plants k leaf is positively dependent on E. Here, this property is termed the dynamic conductance, k leaf(E), which incorporates the inherent k leaf at zero E, which is distinguished as the static conductance, k leaf(0). Growth under different CO₂ concentrations maintained the same relationship between k leaf and E, resulting in similar k leaf(0), while operating along different regions of the curve owing to the influence of CO₂ on g s. The positive relationship between k leaf and E minimized variation in ΔΨstem-leaf. This enables leaves to minimize variation in Ψleaf and maximize g s and CO₂ assimilation rate over the diurnal course of evaporative demand.

  3. Structural comparison of the plant satellite viruses.

    PubMed

    Ban, N; Larson, S B; McPherson, A

    1995-12-20

    Detailed structures are now available for three plant satellite viruses, satellite tobacco necrosis virus (STNV), satellite tobacco mosaic virus (STMV), and satellite panicum mosaic virus (SPMV). It is, therefore, possible to compare the tertiary structure of viral protein subunits, their quaternary interactions, and the interactions of protein subunits with the RNA genome. This analysis indicates that, in spite of common function and preservation of a "jelly-roll" motif in the protein monomer, the three viruses are remarkably different. The differences include the arrangement of secondary structural elements, interactions of adjacent subunits, and the disposition of subunits relative to icosahedral symmetry axes. In each of the three viruses, however, the narrow end of the jelly roll forms fivefold contacts. The fivefold protein interactions are organized about a Ca2+ ion for STNV, an anion for STMV, and, apparently, neither of these for SPMV. Low-resolution neutron diffraction studies using H2O/D2O solvent contrast variation revealed the general location of the RNA genome within the STNV. In the case of SPMV, regions of electron density on the interior of the capsid could be assigned to RNA, although it was not possible to model the nucleic acid. Only for STMV was nucleic acid visible in election density maps, and this was manifested as double-helical RNA segments associated with each coat protein dimer. The observations presented here provide no support for any common evolutionary relationship.

  4. Toward large-area roll-to-roll printed nanophotonic sensors

    NASA Astrophysics Data System (ADS)

    Karioja, Pentti; Hiltunen, Jussi; Aikio, Sanna M.; Alajoki, Teemu; Tuominen, Jarkko; Hiltunen, Marianne; Siitonen, Samuli; Kontturi, Ville; Böhlen, Karl; Hauser, Rene; Charlton, Martin; Boersma, Arjen; Lieberzeit, Peter; Felder, Thorsten; Eustace, David; Haskal, Eliav

    2014-05-01

    Polymers have become an important material group in fabricating discrete photonic components and integrated optical devices. This is due to their good properties: high optical transmittance, versatile processability at relative low temperatures and potential for low-cost production. Recently, nanoimprinting or nanoimprint lithography (NIL) has obtained a plenty of research interest. In NIL, a mould is pressed against a substrate coated with a moldable material. After deformation of the material, the mold is separated and a replica of the mold is formed. Compared with conventional lithographic methods, imprinting is simple to carry out, requires less-complicated equipment and can provide high-resolution with high throughput. Nanoimprint lithography has shown potential to become a method for low-cost and high-throughput fabrication of nanostructures. We show the development process of nano-structured, large-area multi-parameter sensors using Photonic Crystal (PC) and Surface Enhanced Raman Scattering (SERS) methodologies for environmental and pharmaceutical applications. We address these challenges by developing roll-to-roll (R2R) UV-nanoimprint fabrication methods. Our development steps are the following: Firstly, the proof of concept structures are fabricated by the use of wafer-level processes in Si-based materials. Secondly, the master molds of successful designs are fabricated, and they are used to transfer the nanophotonic structures into polymer materials using sheet-level UV-nanoimprinting. Thirdly, the sheet-level nanoimprinting processes are transferred to roll-to-roll fabrication. In order to enhance roll-to-roll manufacturing capabilities, silicone-based polymer material development was carried out. In the different development phases, Photonic Crystal and SERS sensor structures with increasing complexities were fabricated using polymer materials in order to enhance sheet-level and roll-to-roll manufacturing processes. In addition, chemical and molecular

  5. Roll casting of Al-SiCp strip

    NASA Astrophysics Data System (ADS)

    Haga, Toshio

    2016-10-01

    A steel roll with a devised cooling water channel for a vertical type high speed twin roll caster was devised, and was used for strip casting of Al-30vol%SiCp. In the proposed roll caster, the thickness of the wall from the water cooling channel to the roll surface was 4 mm to obtain good cooling conditions. The water cooling channel was machined in the roll core in the lateral direction to prevent convex deformation of the roll. The concave thickness distribution of the strip was improved by the proposed roll. The Al-30vol%SiCp strip had a uniform thickness distribution and could be cast at a speed of 60 m/min. The SiC particles were found to be uniformly distributed, with no obvious agglomeration. The eutectic Si particles were globular and smaller than 3 µm due to the rapid solidification.

  6. Rolled fingerprint construction using MRF-based nonrigid image registration.

    PubMed

    Kwon, Dongjin; Yun, Il Dong; Lee, Sang Uk

    2010-12-01

    This paper proposes a new rolled fingerprint construction approach incorporating a state-of-the-art nonrigid image registration method based upon a Markov random field (MRF) energy model. The proposed method finds dense correspondences between images from a rolled fingerprint sequence and warps the entire fingerprint area to synthesize a rolled fingerprint. This method can generate conceptually more accurate rolled fingerprints by preserving the geometric properties of the finger surface as opposed to ink-based rolled impressions and other existing rolled fingerprint construction methods. To verify the accuracy of the proposed method, various comparative experiments were designed to reveal differences among the rolled construction methods. The results show that the proposed method is significantly superior in various aspects compared to previous approaches.

  7. Large slow roll parameters in single field inflation

    SciTech Connect

    Cook, Jessica L.; Krauss, Lawrence M. E-mail: krauss@asu.edu

    2016-03-01

    We initially consider two simple situations where inflationary slow roll parameters are large and modes no longer freeze out shortly after exiting the horizon, treating both cases analytically. By modes, we refer to the comoving curvature perturbation R. We then consider applications to transient phases where the slow roll parameters can become large, especially in the context of the common 'fast-roll' inflation frequently used as a mechanism to explain the anomalously low scalar power at low l in the CMB. These transient cases we treat numerically. We find when ε, the first slow roll parameter, and only ε is large, modes decay outside the horizon, and when δ, the second slow roll parameter, is large, modes grow outside the horizon. When multiple slow roll parameters are large the behavior in general is more complicated, but we nevertheless show in the 'fast-roll' inflation case, modes grow outside the horizon.

  8. Cotton leaf curl Multan betasatellite as a plant gene delivery vector trans-activated by taxonomically diverse geminiviruses.

    PubMed

    Kharazmi, S; Behjatnia, S A A; Hamzehzarghani, H; Niazi, A

    2012-07-01

    Cotton leaf curl Multan betasatellite (CLCuMB) replicates in tobacco, tomato and datura plants in the presence of the helper viruses tomato leaf curl virus-Australia, Iranian isolates of tomato yellow leaf curl virus, tomato leaf curl Karnataka virus, and beet severe curly top virus (BSCTV). Infectious recombinant CLCuMB constructs were made in which segments of either the CaMV 35S or the petunia ChsA promoter replaced the CLCuMB βC1 ORF, and these were designated pBinβΔC1-35S and pBinβΔC1-ChsA, respectively. Inoculation of tobacco plants containing a functional 35S-GUS transgene with pBinβΔC1-35S, and normal petunia plants with pBinβΔC1-ChsA, in the presence of helper viruses resulted in silencing of GUS and ChsA activities in transgenic tobacco and non-transgenic petunia plants, respectively. Replication of CLCuMB with different geminiviruses, especially BSCTV, a curtovirus with a broad host range, makes it a valuable gene delivery vector to the large number of host plant species of geminiviruses that support CLCuMB.

  9. Dynamics and Stability of Rolling Viscoelastic Tires

    SciTech Connect

    Potter, Trevor

    2013-04-30

    Current steady state rolling tire calculations often do not include treads because treads destroy the rotational symmetry of the tire. We describe two methodologies to compute time periodic solutions of a two-dimensional viscoelastic tire with treads: solving a minimization problem and solving a system of equations. We also expand on work by Oden and Lin on free spinning rolling elastic tires in which they disovered a hierachy of N-peak steady state standing wave solutions. In addition to discovering a two-dimensional hierarchy of standing wave solutions that includes their N-peak hiearchy, we consider the eects of viscoelasticity on the standing wave solutions. Finally, a commonplace model of viscoelasticity used in our numerical experiments led to non-physical elastic energy growth for large tire speeds. We show that a viscoelastic model of Govindjee and Reese remedies the problem.

  10. Rolling-circle transposons in eukaryotes.

    PubMed

    Kapitonov, V V; Jurka, J

    2001-07-17

    All eukaryotic DNA transposons reported so far belong to a single category of elements transposed by the so-called "cut-and-paste" mechanism. Here, we report a previously unknown category of eukaryotic DNA transposons, Helitron, which transpose by rolling-circle replication. Autonomous Helitrons encode a 5'-to-3' DNA helicase and nuclease/ligase similar to those encoded by known rolling-circle replicons. Helitron-like transposons have conservative 5'-TC and CTRR-3' termini and do not have terminal inverted repeats. They contain 16- to 20-bp hairpins separated by 10--12 nucleotides from the 3'-end and transpose precisely between the 5'-A and T-3', with no modifications of the AT target sites. Together with their multiple diverged nonautonomous descendants, Helitrons constitute approximately 2% of both the Arabidopsis thaliana and Caenorhabditis elegans genomes and also colonize the Oriza sativa genome. Sequence conservation suggests that Helitrons continue to be transposed.

  11. Energy dissipation in a rolling aircraft tire

    NASA Technical Reports Server (NTRS)

    Tielking, John T.

    1988-01-01

    The project is extending an existing finite element tire model to calculate the energy dissipation in a free-rolling aircraft tire and temperature buildup in the tire carcass. The model will provide a means of calculating the influence of tire design on the distribution of tire temperature. Current focus is on energy loss measurements of aircraft tire material. The feasibility of taking test specimens directly from the tire carcass for measurements of viscoelastic properties was demonstrated. The interaction of temperature and frequency effects on material loss properties was studied. The tire model was extended to calculate the cyclic energy change in a tire during rolling under load. Input data representing the 40 by 14 aircraft tire whose material loss properties were measured are being used.

  12. Transfer of adhesive tape between calender rolls

    NASA Astrophysics Data System (ADS)

    Johnson, K. L.; Kauzlarich, J. J.

    2004-03-01

    In the calendering process a tape or sheet of deformable material passes through the nip between hard cylindrical rollers. Usually the rolls are driven at the same peripheral speed, but small differences in speed, often referred to as 'creep', can occur if one of the rolls is externally driven and the other is driven by the friction in the contact. In these circumstances it has been observed that a tape that enters the nip adhering to the driven (slower) surface may transfer at exit to the driving (faster) surface but not the other way round. The mechanics of this transfer process is examined theoretically and experimentally in this paper for the case of double sided adhesive tape. It is argued that on emerging from the nip the tape will separate from the surface at which the shear strain in the adhesive is greater and that for transfer to occur the contact load must be sufficient to cause plastic extension of the tape.

  13. A variant of Rubus yellow net virus with altered genomic organization.

    PubMed

    Diaz-Lara, Alfredo; Mosier, Nola J; Keller, Karen E; Martin, Robert R

    2015-02-01

    Rubus yellow net virus (RYNV) is a member of the genus Badnavirus (family: Caulimoviridae). RYNV infects Rubus species causing chlorosis of the tissue along the leaf veins, giving an unevenly distributed netted symptom in some cultivars of red and black raspberry. Recently, a strain of RYNV was sequenced from a Rubus idaeus plant in Alberta, Canada, exhibiting such symptoms. The viral genome contained seven open reading frames (ORFs) with five of them in the sense-strand, including a large polyprotein. Here we describe a graft-transmissible strain of RYNV from Europe infecting cultivar 'Baumforth's Seedling A' (named RYNV-BS), which was sequenced using rolling circle amplification, enzymatic digestion, cloning and primer walking, and it was resequenced at a 5X coverage. This sequence was then compared with the RYNV-Ca genome and significant differences were observed. Genomic analysis identified differences in the arrangement of coding regions, promoter elements, and presence of motifs. The genomic organization of RYNV-BS consisted of five ORFs (four ORFs in the sense-strand and one ORF in the antisense-strand). ORFs 1, 2, and 3 showed a high degree of homology to RYNV-Ca, while ORFs 4 and 6 of RYNV-BS were quite distinct. Also, the predicted ORFs 5 and 7 in the RYNV-Ca were absent in the RYNV-BS sequence. These differences may account for the lack of aphid transmissibility of RYNV-BS.

  14. Sequence analysis and location of capsid proteins within RNA 2 of strawberry latent ringspot virus.

    PubMed

    Kreiah, S; Strunk, G; Cooper, J I

    1994-09-01

    The nucleotide sequence of the RNA 2 of a strawberry isolate (H) of strawberry latent ringspot virus (SLRSV) comprised 3824 nucleotides and contained one long open reading frame with a theoretical coding capacity of 890 amino acids equivalent to a protein of 98.8K. The N-terminal amino acid sequences of virion-derived proteins were determined by Edman degradation allowing the capsid coding regions to be located and serine/glycine cleavage sites to be identified within the polyprotein. The amino acid sequence in the capsid coding region of an isolate of SLRSV from flowering cherry in New Zealand was 97% identical to that of SLRSV-H. Except in the 3' and 5' terminal non-coding sequences, computer-based alignment and comparison algorithms did not reveal any substantial homologies between RNA 2 of SLRSV-H and the equivalent genomic segments in the nepoviruses arabis mosaic, cherry leaf roll, grapevine fanleaf, raspberry ringspot, grapevine hungarian chrome mosaic, tomato blackring, tomato ringspot, tobacco ringspot, or in the comoviruses cowpea mosaic and red clover mottle. Despite the similarities in overall genome organization, data from RNA 2 remain insufficient for unambiguous positioning of SLRSV in relation to species/genera in the Comoviridae.

  15. [WHO's malaria program Roll Back Malaria].

    PubMed

    Myrvang, B; Godal, T

    2000-05-30

    Malaria is one of the main health problems in the world with 300-500 millions cases yearly and about one million deaths, mainly children in Sub-Saharan Africa. In the 1990s the malaria problem in Africa has increased, although we have methods to control the disease. In 1998 the new secretary general of WHO, Gro Harlem Brundtland, established the Roll Back Malaria programme, with the aim to markedly reduce malaria morbidity and mortality. Governments in malaria-affected countries have to take the lead in Roll Back Malaria. Their health systems must be improved and malaria control integrated into the general health system, and the methods available for prevention and treatment have to be intensified and improved. At the same time, Roll Back Malaria will encourage and promote malaria research which hopefully will result in new medicines, vaccines and other tools which will improve the chances of reducing malaria-related deaths and suffering. Roll Back Malaria is a cabinet project within the WHO, and the organisation has a key role as manager, co-ordinator and monitor of the project. However, it depends for resources on international support and commitment from other UN bodies, the World Bank, governments in the western world, pharmaceutical industry, philanthropists and other sources. At present an optimistic view prevails, and the preliminary aim, to halve the malaria mortality by the year 2010, seems realistic even with the control methods of today. However, if research efforts result in new and better tools to combat the disease, the task will definitely be easier.

  16. Extreme chirality in Swiss roll metamaterials.

    PubMed

    Demetriadou, A; Pendry, J B

    2009-09-16

    The chiral Swiss roll metamaterial is a resonant, magnetic medium that exhibits a negative refractive band for one-wave polarization. Its unique structure facilitates huge chiral effects: a plane polarized wave propagating through this system can change its polarization by 90° in less than a wavelength. Such chirality is at least 100 times greater than previous structures have achieved. In this paper, we discuss this extreme chiral behaviour with both numerical and analytical results.

  17. Rolling circle amplification of metazoan mitochondrialgenomes

    SciTech Connect

    Simison, W. Brian; Lindberg, D.R.; Boore, J.L.

    2005-07-31

    Here we report the successful use of rolling circle amplification (RCA) for the amplification of complete metazoan mt genomes to make a product that is amenable to high-throughput genome sequencing techniques. The benefits of RCA over PCR are many and with further development and refinement of RCA, the sequencing of organellar genomics will require far less time and effort than current long PCR approaches.

  18. Rolling Bearing Life Prediction, Theory, and Application

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin V.

    2013-01-01

    A tutorial is presented outlining the evolution, theory, and application of rolling-element bearing life prediction from that of A. Palmgren, 1924; W. Weibull, 1939; G. Lundberg and A. Palmgren, 1947 and 1952; E. Ioannides and T. Harris, 1985; and E. Zaretsky, 1987. Comparisons are made between these life models. The Ioannides-Harris model without a fatigue limit is identical to the Lundberg-Palmgren model. The Weibull model is similar to that of Zaretsky if the exponents are chosen to be identical. Both the load-life and Hertz stress-life relations of Weibull, Lundberg and Palmgren, and Ioannides and Harris reflect a strong dependence on the Weibull slope. The Zaretsky model decouples the dependence of the critical shear stress-life relation from the Weibull slope. This results in a nominal variation of the Hertz stress-life exponent. For 9th- and 8th-power Hertz stress-life exponents for ball and roller bearings, respectively, the Lundberg- Palmgren model best predicts life. However, for 12th- and 10th-power relations reflected by modern bearing steels, the Zaretsky model based on the Weibull equation is superior. Under the range of stresses examined, the use of a fatigue limit would suggest that (for most operating conditions under which a rolling-element bearing will operate) the bearing will not fail from classical rolling-element fatigue. Realistically, this is not the case. The use of a fatigue limit will significantly overpredict life over a range of normal operating Hertz stresses. Since the predicted lives of rolling-element bearings are high, the problem can become one of undersizing a bearing for a particular application.

  19. Modeling recrystallization kinetics during strip rolling

    SciTech Connect

    Sun, W.P.; Hawbolt, E.B.; Meadowcroft, T.R.

    1995-01-01

    In order to simulate the microstructural evolution during hot strip rolling, double-hit compression tests have been carried out on plain carbon steels. Using the softening data obtained by these tests, mathematical models were developed to predict the overall kinetics of static recrystallization under roughing and finishing mill conditions. These models include the effects of deformation temperature, applied strain, strain rate and initial austenite grain size. Predictions based on these models are in reasonable agreement with the present experimental results.

  20. Texture Evolution of a Non-oriented Electrical Steel Cold Rolled at Directions Different from the Hot Rolling Direction

    NASA Astrophysics Data System (ADS)

    He, Youliang; Hilinski, Erik; Li, Jian

    2015-11-01

    With the objective of optimizing the crystallographic texture of non-oriented electrical steel, i.e., reducing the <111>//ND and <110>//RD fibers and promoting the <001>//ND texture, a new rolling scheme was proposed and tested, in which the cold rolling direction (CRD) was intentionally inclined at an angle to the hot rolling direction (HRD) in order to change the orientation flow paths during cold rolling and alter the final texture of the annealed sheets. A non-oriented electrical steel containing 0.88 wt pct Si was hot rolled using conventional routes and annealed, and a number of rectangular plates were cut from the hot band with the longitudinal directions inclined at various angles, i.e., 0, 15, 30, 45, 60, 75, and 90 deg, to the HRD. These plates were then cold rolled along the longitudinal directions with a thickness reduction of 72 pct. The cold-rolled samples were annealed, temper rolled and annealed again (final annealing). The texture evolution during hot rolling, hot band annealing, cold rolling, and final annealing was characterized by electron backscatter diffraction and X-ray diffraction techniques. By changing the CRD with respect to the HRD, the initial texture and the orientation flow paths were altered, which resulted in apparent differences in the textures as compared to conventional cold rolling. After temper rolling and final annealing, the recrystallization textures consisted of mainly a <001>//ND fiber and there was almost no <111>//ND fiber. The sample cold rolled at an angle of 60 deg to the HRD had the strongest texture (intensity almost 2× of conventional rolling) with a maximum at the cube {001}<100> orientation—a magnetically favorable orientation for non-oriented electrical steels.