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Leaf Virus (leaf + virus)
Kinds of Leaf Virus Selected AbstractsProduction of Monoclonal Antibodies to Sugarcane Yellow Leaf Virus Using Recombinant Readthrough ProteinJOURNAL OF PHYTOPATHOLOGY, Issue 8-9 2002J. Korimbocus Abstract Yellow leaf syndrome (YLS) of sugarcane is associated with sugarcane yellow leaf virus (SCYLV), a member of the family Luteoviridae. A fragment of the coat protein and readthrough domain of SCYLV wasexpressed in a bacterial expression system. The resulting protein was purified and used to immunize mice for monoclonal antibody (MAb) production. Two MAbs, 3A2E3 and 2F7H5, were selected following the screening of hybridoma cells using both plate-trapped antigen enzyme-linked immunosorbent assay (PTA-ELISA) and tissue blot immunoassay (TBIA). These MAbs can be incorporated into the TBIA assay currently used for the routine detection of SCYLV but could not be used in triple antibody sandwich enzyme-linked immunosorbent assay (TAS-ELISA). The two antibodies selected have slightly different specificities. Antibody 3A2E3 gave equivalent results to a polyclonal antiserum (raised to purified virus) in comparative testing using TBIA. The MAbs produced should provide a widely available, uniform reagent for SCYLV diagnosis with the potential to help manage YLS. [source] Genome Organization of an Infectious Clone of Tomato Leaf Curl Virus (Philippines), a New Monopartite Begomovirus*JOURNAL OF PHYTOPATHOLOGY, Issue 11-12 2002Tatsuya Kon Abstract Complete nucleotide sequence of infectious cloned DNA of Tomato leaf curl virus from Philippines (ToLCV-Ph) was determined. The single circular DNA molecule comprises 2755 nucleotides. ToLCV-Ph DNA contains six open reading frames (ORFs) each capable of encoding proteins with a molecular weight greater than 10 kDa. A partial dimeric ToLCV-Ph DNA clone was constructed in a binary vector and used to agroinoculate tomato plants (Lycopersicon esculentum Mill. cv. Zuikou 102). Typical leaf curl symptoms were observed, showing that the single DNA component is sufficient for infectivity. In total nucleotide sequence comparisons with other geminiviruses, ToLCV-Ph was most closely related to Ageratum yellow vein virus (AYVV) (79% identity), ToLCV-Laos (78%), Soyabean crinkle leaf virus -Thailand (78%) and ToLCV-Taiwan (77%). The significant but relatively low sequence identity in the genomic DNA between ToLCV-Ph and other geminiviruses suggests that it is a distinct geminivirus in the genus Begomovirus. [source] Production of Monoclonal Antibodies to Sugarcane Yellow Leaf Virus Using Recombinant Readthrough ProteinJOURNAL OF PHYTOPATHOLOGY, Issue 8-9 2002J. Korimbocus Abstract Yellow leaf syndrome (YLS) of sugarcane is associated with sugarcane yellow leaf virus (SCYLV), a member of the family Luteoviridae. A fragment of the coat protein and readthrough domain of SCYLV wasexpressed in a bacterial expression system. The resulting protein was purified and used to immunize mice for monoclonal antibody (MAb) production. Two MAbs, 3A2E3 and 2F7H5, were selected following the screening of hybridoma cells using both plate-trapped antigen enzyme-linked immunosorbent assay (PTA-ELISA) and tissue blot immunoassay (TBIA). These MAbs can be incorporated into the TBIA assay currently used for the routine detection of SCYLV but could not be used in triple antibody sandwich enzyme-linked immunosorbent assay (TAS-ELISA). The two antibodies selected have slightly different specificities. Antibody 3A2E3 gave equivalent results to a polyclonal antiserum (raised to purified virus) in comparative testing using TBIA. The MAbs produced should provide a widely available, uniform reagent for SCYLV diagnosis with the potential to help manage YLS. [source] Physiological Performance of Asymptomatic and Yellow Leaf Syndrome-affected Sugarcanes in VenezuelaJOURNAL OF PHYTOPATHOLOGY, Issue 1 2002M. L. IZAGUIRRE-MAYORAL Serological analyses revealed the presence of the sugarcane yellow leaf virus (ScYLV) in asymptomatic (S,) and symptomatic (S+) yellow leaf syndrome-affected sugarcane plants of the cultivars PR.692176, C.323,68, V.64,10, V.71,47, V.75,6, SP.72,2086, SP.72,1210, SP.74,2005, C.323,68, B.80,549 and B.82,363. Tests for the presence of the sugarcane yellows phytoplasma, carried out by Dr P. Jones (IACR-Rothamsted), gave negative results in all cultivars. Physiological analyses were performed in the top visible dewlap (TVD) leaf of S, and S+ plants of the cultivar PR.692176. All plants were at the second ratoon and flowering. When compared with S, plants, the S+ plants showed: (a) a marked reduction in the area of the leaf and internodes; (b) a high accumulation of total reducing sugars (TRS), glucans and ,-amino-N in the leaf blade and of TRS in the corresponding leaf sheath; (c) a decrease in the chlorophyll, phosphorus and nitrogen content in the leaf; (d) the disappearance of the leaf diurnal fluctuations in TRS accumulation and export as well as the daily oscillations of TRS and glucans between dawn and dusk; and (e) major ultrastructural alterations in the companion cells of the phloem, including the accumulation of ScYLV particles in the cytoplasm. In S, plants, none of the growth and physiological alterations described above were observed, in spite of the high density of ScYLV particles in the cytoplasm. The location of S, and S+ plants close to each other without a discernible pattern of distribution in plots subjected to optimal irrigation and fertilization rule out the possibility that environmental conditions underlay the appearance of symptoms. In plots under severe drought for 3 months, however, all S, plants become S+. Symptom expression did not affect the acid phosphatase activity in the rhizosphere of S+ plants. [source] About charge-transport mechanisms in mesoporous silicon under adsorption of plant virusesPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 7 2009Yuriy Vashpanov Abstract Changes in the electric parameters and the charge-transport mechanism in a mesoporous silicon under adsorption of TORSV (tomato ringspot virus) and GFLV (grapevine fan leaf virus) NEPO-viruses are analyzed. The mechanism influencing the electric characteristics of the mesoporous silicon under adsorption of the plant viruses is related with the changes in parameters of a potential-barrier system due to redistribution of voltages at the silicon structure. The mechanism of charge transport in the mesoporous silicon is more likely connected to the changes in parameters of isotopic heterojunction barriers under small bias voltages, and it can be interpreted as Poole,Frenkel and tunnel conductivity for large bias. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] A generic RT-PCR assay for the detection of LuteoviridaePLANT PATHOLOGY, Issue 3 2010A. Chomi This study, using RT-PCR, is the first comprehensive assessment since 1991 of a generic detection method for the Luteoviridae. Thirteen Luteoviridae species were detected using three separate sets of low-degeneracy generic primers with RT-PCR to amplify 68-, 75- and 129/156-bp regions of the Luteoviridae coat-protein gene. Species detected include all members of the genus Luteovirus [Barley yellow dwarf virus (BYDV) -PAV, BYDV-PAS, BYDV-MAV (129 and/or 156 bp amplicons), Soybean dwarf virus, Bean leafroll virus (68 bp amplicon)] and eight of nine species from the genus Polerovirus [Beet western yellows virus, Beet chlorosis virus, Beet mild yellowing virus, Turnip yellows virus, Potato leafroll virus, Cucurbit aphid-borne yellows virus, Cereal yellow dwarf virus-RPV (68-bp amplicon) and Sugarcane yellow leaf virus (75-bp amplicon)]. These primers were not able to detect Carrot red leaf virus, Sweet potato leaf speckling virus (both belong to unassigned Luteoviridae) and Pea enation mosaic virus-1 (genus Enamovirus). A synthetic positive control containing all primer sequence priming sites was designed to facilitate this method as a generic tool for use with a variety of host plants. The Luteoviridae primers described in this study present a simple infection-detection tool of benefit to biosecurity authorities in nursery-stock surveillance, disease management or outbreak prevention, and may also be useful in detection of as-yet undiscovered species within the Luteovirus and Polerovirus genera. [source] Variation in virus populations and growth characteristics of two sugarcane cultivars naturally infected by Sugarcane yellow leaf virus in different geographical locationsPLANT PATHOLOGY, Issue 5 2007Y. Abu Ahmad Two sugarcane cultivars (R570 and SP71-6163) naturally infected by Sugarcane yellow leaf virus (SCYLV) were each imported from several geographical locations into a sugarcane yellow leaf-free environment (Montpellier, France). Plants were grown as plant cane for 5,6 months and the experiment was repeated for three consecutive years (2003,2005) in a greenhouse. Several sugarcane-growth and disease characteristics were monitored to identify variation in pathogenicity of SCYLV. Depending on their geographical origin, sugarcane cvs R570 and SP71-6163 were infected by SCYLV genotypes BRA-PER or REU, or a mixture of the two. Severity of symptoms did not vary between plants of cv. R570, but variation in disease severity between plants of cv. SP71-6163 from different geographical locations suggested the occurrence of pathogenic variants of SCYLV. For each sugarcane cultivar, differences in stalk length, number of stalk internodes, virus titre in the top visible dewlap leaf, and percentage of infection of leaf and stalk phloem vessels were also found between plants from different geographical origins. However, these differences were not always reproducible from one year to another, suggesting occurrence of different plant responses to SCYLV isolates under varying environmental conditions. [source] Movement of aphid-transmitted Sugarcane yellow leaf virus (ScYLV) within and between sugarcane plantsPLANT PATHOLOGY, Issue 4 2007A. T. Lehrer Sugarcane yellow leaf virus (ScYLV) is distributed worldwide and has been shown to be the cause of the disease sugarcane yellow leaf syndrome (YLS). This study was an investigation of the transmission and spread of ScYLV in Hawaii. Several aphids are known to transmit the virus, but investigation of infestation and transmission efficiency showed Melanaphis sacchari to be the only vector important for field spread of the disease. The initial multiplication of ScYLV in a virus-free plant occurred exclusively in very young sink tissues. When a single leaf was inoculated on a plant, that leaf and all older leaves remained virus-free, based on tissue-blot immunoassay, whereas meristems and all subsequently formed new leaves became infected. Therefore, only after those leaves which had already developed before inoculation had been shed, did the complete plant contain ScYLV. Spread of the viral infection to neighbouring plants in the plantation fields via aphids was relatively slow and in the range of a few metres per year. No indication of long-distance transfer could be seen. This indicates that it may be possible to produce and use virus-free seed cane for planting of high-yielding but YLS-susceptible cultivars. [source] |