The Experts below are selected from a list of 405 Experts worldwide ranked by ideXlab platform
Kay Scheets - One of the best experts on this subject based on the ideXlab platform.
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the rna of Maize Chlorotic Mottle virus an obligatory component of Maize lethal necrosis disease is translated via a variant panicum mosaic virus like cap independent translation element
Journal of Virology, 2020Co-Authors: Elizabeth J Carino, Kay Scheets, Allen W MillerAbstract:Maize Chlorotic Mottle virus (MCMV) combines with a potyvirus in Maize lethal necrosis disease (MLND), a serious emerging disease worldwide. To inform resistance strategies, we characterized the translation initiation mechanism of MCMV. We report that MCMV RNA contains a cap-independent translation element (CITE) in its 3' untranslated region (UTR). The MCMV 3' CITE (MTE) was mapped to nucleotides 4164 to 4333 in the genomic RNA. 2'-Hydroxyl acylation analyzed by primer extension (SHAPE) probing revealed that the MTE is a distinct variant of the panicum mosaic virus-like 3' CITE (PTE). Like the PTE, electrophoretic mobility shift assays (EMSAs) indicated that eukaryotic translation initiation factor 4E (eIF4E) binds the MTE despite the absence of an m7GpppN cap structure, which is normally required for eIF4E to bind RNA. Using a luciferase reporter system, mutagenesis to disrupt and restore base pairing revealed that the MTE interacts with the 5' UTRs of both genomic RNA and subgenomic RNA1 via long-distance kissing stem-loop interaction to facilitate translation. The MTE stimulates a relatively low level of translation and has a weak, if any, pseudoknot, which is present in the most active PTEs, mainly because the MTE lacks the pyrimidine-rich tract that base pairs to a G-rich bulge to form the pseudoknot. However, most mutations designed to form a pseudoknot decreased translation activity. Mutations in the viral genome that reduced or restored translation prevented and restored virus replication, respectively, in Maize protoplasts and in plants. In summary, the MTE differs from the canonical PTE but falls into a structurally related class of 3' CITEs.IMPORTANCE In the past decade, Maize lethal necrosis disease has caused massive crop losses in East Africa. It has also emerged in China and parts of South America. Maize Chlorotic Mottle virus (MCMV) infection is required for this disease. While some tolerant Maize lines have been identified, there are no known resistance genes that confer immunity to MCMV. In order to improve resistance strategies against MCMV, we focused on how the MCMV genome is translated, the first step of gene expression by all positive-strand RNA viruses. We identified a structure (cap-independent translation element) in the 3' untranslated region of the viral RNA genome that allows the virus to usurp a host translation initiation factor, eIF4E, in a way that differs from host mRNA interactions with the translational machinery. This difference indicates eIF4E may be a soft target for engineering of-or breeding for-resistance to MCMV.
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first report of Maize Chlorotic Mottle virus and Maize lethal necrosis in kenya
Plant Disease, 2012Co-Authors: Anne Wangai, Kay Scheets, Margaret G. Redinbaugh, D W Miano, Z M Kinyua, P K Leley, M Kasina, George Mahuku, Dan JeffersAbstract:In September 2011, a high incidence of a new Maize (Zea mays L.) disease was reported at lower elevations (1,900 m asl) in the Longisa division of Bomet County, Southern Rift Valley, Kenya. The disease later spread to the Narok South and North and Naivasha Districts. By March 2012, the disease was reported at up to 2,100 m asl. Diseased plants had symptoms characteristic of virus diseases: a Chlorotic Mottle on leaves, developing from the base of young whorl leaves upward to the leaf tips; mild to severe leaf mottling; and necrosis developing from leaf margins to the mid-rib. Necrosis of young leaves led to a “dead heart” symptom, and plant death. Severely affected plants had small cobs with little or no grain set. Plants frequently died before tasseling. All Maize varieties grown in the affected areas had similar symptoms. In these regions, Maize is grown continuously throughout the year, with the main planting season starting in November. Maize streak virus was present, but incidence was low (data not s...
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Maize Chlorotic Mottle machlomovirus and wheat streak mosaic rymovirus concentrations increase in the synergistic disease corn lethal necrosis
Virology, 1998Co-Authors: Kay ScheetsAbstract:Corn lethal necrosis (CLN) is caused by the synergistic interaction between Maize Chlorotic Mottle machlomovirus (MCMV) and any potyvirus which infects cereals. Interactions between MCMV and wheat streak mosaic rymovirus (WSMV) in N28Ht corn produced MCMV concentrations that averaged 3.3- to 11.2-fold higher in doubly infected plants than the average concentrations in plants inoculated with MCMV. MCMV-negative sense RNA concentrations were similarly increased, and the ratio of full-length to subgenomic RNA was the same in singly and doubly infected plants. Contrary to most synergisms involving a potyvirus, WSMV infections were enhanced by the presence of MCMV. WSMV infection rates were higher when plants were coinoculated with MCMV, and the difference in infection rates was more pronounced at higher temperatures. Under conditions favorable for establishing high WSMV infection rates (cooler temperatures and high light intensity), WSMV concentrations in doubly infected plants averaged 2.1- to 3.1-fold higher than those in singly inoculated plants. Doubly inoculated plants with the lowest WSMV levels also had the lowest MCMV concentrations, but the concentrations of MCMV and WSMV in the most heavily infected plants did not directly correlate. These results suggest that there are genes in both MCMV and WSMV which directly or indirectly affect the replication and/or spread of the other virus in CLN.
Roy French - One of the best experts on this subject based on the ideXlab platform.
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Complete nucleotide sequence of a Maize Chlorotic Mottle virus isolate from Nebraska
Archives of Virology, 2008Co-Authors: Drake C Stenger, Roy FrenchAbstract:The complete genome of a Maize Chlorotic Mottle virus isolate from Nebraska (MCMV-NE) was cloned and sequenced. The MCMV-NE genome consists of 4,436 nucleotides and shares 99.5 nucleotide sequence identity with an MCMV isolate from Kansas (MCMV-KS). Of 22 polymorphic sites, most resulted from transition with a clear bias for U to C and C to U substitutions. The MCMV-NE genome was assembled into a single plasmid insert and used as a template to transcribe RNA in vitro. As RNA transcribed from the cloned MCMV-NE genome was infectious to Maize plants, sequence differences between MCMV-NE and MCMV-KS are most likely neutral with respect to pathogenicity and virulence.
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Wheat streak mosaic virus Lacking Helper Component-Proteinase Is Competent to Produce Disease Synergism in Double Infections with Maize Chlorotic Mottle virus.
Phytopathology, 2007Co-Authors: Drake C Stenger, Brock A. Young, T. Jack Morris, Roy FrenchAbstract:Stenger, D. C., Young, B. A., Qu, F., Morris, T. J., and French, R. 2007. Wheat streak mosaic virus lacking helper component-proteinase is competent to produce disease synergism in double infections with Maize Chlorotic Mottle virus. Phytopathology 97:1213-1221. The tritimovirus Wheat streak mosaic virus (WSMV) and the machlomovirus Maize Chlorotic Mottle virus (MCMV) each cause systemic chlorosis in infected Maize plants. Infection of Maize with both viruses produces corn lethal necrosis disease (CLND). Here, we report that complete deletion of the WSMV helper component-proteinase (HC-Pro) coding region had no effect on induction of CLND symptoms following coinoculation of Maize with WSMV and MCMV. We further demonstrated that elevation of virus titers in double infections, relative to single infections, also was independent of WSMV HC-Pro. Thus, unlike potyvirus HC-Pro, WSMV HC-Pro was dispensable for disease synergism. Because disease synergism involving potyviruses requires HC-Promediated suppression of posttranscriptional gene silencing (PTGS), we hypothesized that WSMV HC-Pro may not be a suppressor of PTGS. Indeed, WSMV HC-Pro did not suppress PTGS of a green fluorescent protein (GFP) transgene in an Agrobacterium-mediated coinfiltration assay in which potyvirus HC-Pro acted as a strong suppressor. Furthermore, coinfiltration with potyvirus HC-Pro, but not WSMV HC-Pro, resulted in elevated levels of the GFP target mRNA under conditions which trigger PTGS. Collectively, these results revealed significant differences in HC-Pro function among divergent genera of the family Potyviridae and suggest that the tritimovirus WSMV utilizes a gene other than HC-Pro to suppress PTGS and mediate synergistic interactions with unrelated viruses.
Margaret G. Redinbaugh - One of the best experts on this subject based on the ideXlab platform.
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selecting for coupling phase recombination between potyvirus resitance and white endosperm colour in Maize preferred by farmers in sub saharan africa ssa
Afrika Focus, 2019Co-Authors: Victoria B Bulegeya, Mark W Jones, Tryphone G Muhamba, Biswanath Das, Peter R Thomison, David M Francis, Margaret G. RedinbaughAbstract:Maize lethal necrosis (MLN) disease caused by a combined infection of Maize Chlorotic Mottle virus (MCMV) and any cereal infecting potyvirus is a threat to food security in Sub-Saharan Africa (SSA). Resistance to potyvirus has been extensively studied and Mdm1 gene for potyvirus resistance on chromosome 6 of Maize is linked to Y1 gene for Maize endosperm colour. This study is aimed at se- lecting for coupling-phase recombination of potyvirus resistance and white endosperm colour. White susceptible Maize lines CML333 and CML277 were crossed with a yellow resistant line, Pa405, to produce F1 and F2 progenies. Progenies were screened using molecular markers to recover 22 white endosperm recombinants. 22 selections were advanced to F3 recombinant families, and 10 were as- sayed for their responses to Maize dwarf mosaic virus (MDMV) and Sugarcane mosaic virus (SCMV). Four families segregated for SCMV resistance, selection of homozygous recombinants within these families will provide lines appropriate for improving lines with resistance to SCMV and MLN resistance in SSA. KEY WORDS: Maize LETHAL NECROSIS (MLN), WHITE Maize, POTYVIRUS RESISTANCE, GENETIC RECOMBINATION, SUB-SAHARAN AFRICA.
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diverse chromosomal locations of quantitative trait loci for tolerance to Maize Chlorotic Mottle virus in five Maize populations
Phytopathology, 2017Co-Authors: Mark W Jones, Margaret G. Redinbaugh, Bryan W Penning, Tiffany M Jamann, Jeff Glaubitz, Cinta Romay, Edward S BucklerAbstract:The recent rapid emergence of Maize lethal necrosis (MLN), caused by coinfection of Maize with Maize Chlorotic Mottle virus (MCMV) and a second virus usually from the family Potyviridae, is causing extensive losses for farmers in East Africa, Southeast Asia, and South America. Although the genetic basis of resistance to potyviruses is well understood in Maize, little was known about resistance to MCMV. The responses of five Maize inbred lines (KS23-5, KS23-6, N211, DR, and Oh1VI) to inoculation with MCMV, Sugarcane mosaic virus, and MLN were characterized. All five lines developed fewer symptoms than susceptible controls after inoculation with MCMV; however, the virus was detected in systemic leaf tissue from each of the lines similarly to susceptible controls, indicating that the lines were tolerant of MCMV rather than resistant to it. Except for KS23-5, the inbred lines also developed fewer symptoms after inoculation with MLN than susceptible controls. To identify genetic loci associated with MCMV tolerance, large F2 or recombinant inbred populations were evaluated for their phenotypic responses to MCMV, and the most resistant and susceptible plants were genotyped by sequencing. One to four quantitative trait loci (QTL) were identified in each tolerant population using recombination frequency and positional mapping strategies. In contrast to previous studies of virus resistance in Maize, the chromosomal positions and genetic character of the QTL were unique to each population. The results suggest that different, genotype-specific mechanisms are associated with MCMV tolerance in Maize. These results will allow for the development of markers for marker-assisted selection of MCMV- and MLN-tolerant Maize hybrids for disease control.
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johnsongrass mosaic virus contributes to Maize lethal necrosis in east africa
Plant Disease, 2017Co-Authors: Lucy R Stewart, Kristen Willie, Deogracious Massawe, Margaret G. Redinbaugh, Saranga Wijeratne, C L Niblett, Andrew Kiggundu, Theodore AsiimweAbstract:Maize lethal necrosis (MLN), a severe virus disease of Maize, has emerged in East Africa in recent years with devastating effects on production and food security where Maize is a staple subsistence crop. In extensive surveys of MLN-symptomatic plants in East Africa, sequences of Johnsongrass mosaic virus (JGMV) were identified in Uganda, Kenya, Rwanda, and Tanzania. The East African JGMV is distinct from previously reported isolates and infects Maize, sorghum, and Johnsongrass but not wheat or oat. This isolate causes MLN in coinfection with Maize Chlorotic Mottle virus (MCMV), as reported for other potyviruses, and was present in MLN-symptomatic plants in which the major East African potyvirus, Sugarcane mosaic virus (SCMV), was not detected. Virus titers were compared in single and coinfections by quantitative reverse transcription-polymerase chain reaction. MCMV titer increased in coinfected plants whereas SCMV, Maize dwarf mosaic virus, and JGMV titers were unchanged compared with single infections at...
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first report of Maize Chlorotic Mottle virus and Maize lethal necrosis in kenya
Plant Disease, 2012Co-Authors: Anne Wangai, Kay Scheets, Margaret G. Redinbaugh, D W Miano, Z M Kinyua, P K Leley, M Kasina, George Mahuku, Dan JeffersAbstract:In September 2011, a high incidence of a new Maize (Zea mays L.) disease was reported at lower elevations (1,900 m asl) in the Longisa division of Bomet County, Southern Rift Valley, Kenya. The disease later spread to the Narok South and North and Naivasha Districts. By March 2012, the disease was reported at up to 2,100 m asl. Diseased plants had symptoms characteristic of virus diseases: a Chlorotic Mottle on leaves, developing from the base of young whorl leaves upward to the leaf tips; mild to severe leaf mottling; and necrosis developing from leaf margins to the mid-rib. Necrosis of young leaves led to a “dead heart” symptom, and plant death. Severely affected plants had small cobs with little or no grain set. Plants frequently died before tasseling. All Maize varieties grown in the affected areas had similar symptoms. In these regions, Maize is grown continuously throughout the year, with the main planting season starting in November. Maize streak virus was present, but incidence was low (data not s...
Xueping Zhou - One of the best experts on this subject based on the ideXlab platform.
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Nitric Oxide as a Downstream Signaling Molecule in Brassinosteroid-Mediated Virus Susceptibility to Maize Chlorotic Mottle Virus in Maize
MDPI AG, 2019Co-Authors: Ning Cao, Binhui Zhan, Xueping ZhouAbstract:Maize Chlorotic Mottle virus (MCMV) infection causes growth abnormalities in Maize. Transcriptome sequencing was conducted to compare the global gene expression of MCMV-inoculated plants with that of mock-inoculated plants. Data analyses showed that brassinosteroid (BR)-associated genes were upregulated after MCMV infection. Exogenous 2,4-epibrassinolide (BL) or brassinazole (BRZ) applications indicated that BR pathway was involved in the susceptibility to MCMV infection. In addition, treatment of BL on Maize induced the accumulation of nitric oxide (NO), and the changes of NO content played positive roles in the disease incidence of MCMV. Moreover, MCMV infection was delayed when the BL-treated plants were applied with NO scavenger, which suggested that BR induced the susceptibility of Maize to MCMV infection in a NO-dependent manner. Further investigation showed the Maize plants with knock-down of DWARF4 (ZmDWF4, a key gene of BR synthesis) and nitrate reductase (ZmNR, a key gene of NO synthesis) by virus-induced gene silencing displayed higher resistance to MCMV than control plants. Taken together, our results suggest that BR pathway promotes the susceptibility of Maize to MCMV in a NO-dependent manner
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further characterization of Maize Chlorotic Mottle virus and its synergistic interaction with sugarcane mosaic virus in Maize
Scientific Reports, 2017Co-Authors: Qiang Wang, Yajuan Qian, Zhenghe Li, Chunyan Wang, Jian Hong, Chao Zhang, Xueping ZhouAbstract:Maize Chlorotic Mottle virus (MCMV) was first reported in Maize in China in 2009. In this study we further analyzed the epidemiology of MCMV and corn lethal necrosis disease (CLND) in China. We determined that CLND observed in China was caused by co-infection of MCMV and sugarcane mosaic virus (SCMV). Phylogenetic analysis using four full-length MCMV cDNA sequences obtained in this study and the available MCMV sequences retrieved from GenBank indicated that Chinese MCMV isolates were derived from the same source. To screen for Maize germplasm resistance against MCMV infection, we constructed an infectious clone of MCMV isolate YN2 (pMCMV) and developed an Agrobacterium-mediated injection procedure to allow high throughput inoculations of Maize with the MCMV infectious clone. Electron microscopy showed that chloroplast photosynthesis in leaves was significantly impeded by the co-infection of MCMV and SCMV. Mitochondria in the MCMV and SCMV co-infected cells were more severely damaged than in MCMV-infected cells. The results of this study provide further insight into the epidemiology of MCMV in China and shed new light on physiological and cytopathological changes related to CLND in Maize.
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further characterization of Maize Chlorotic Mottle virus and its synergistic interaction with sugarcane mosaic virus in Maize
Scientific Reports, 2017Co-Authors: Qiang Wang, Yajuan Qian, Zhenghe Li, Chunyan Wang, Jian Hong, Chao Zhang, Xueping ZhouAbstract:Maize Chlorotic Mottle virus (MCMV) was first reported in Maize in China in 2009. In this study we further analyzed the epidemiology of MCMV and corn lethal necrosis disease (CLND) in China. We determined that CLND observed in China was caused by co-infection of MCMV and sugarcane mosaic virus (SCMV). Phylogenetic analysis using four full-length MCMV cDNA sequences obtained in this study and the available MCMV sequences retrieved from GenBank indicated that Chinese MCMV isolates were derived from the same source. To screen for Maize germplasm resistance against MCMV infection, we constructed an infectious clone of MCMV isolate YN2 (pMCMV) and developed an Agrobacterium-mediated injection procedure to allow high throughput inoculations of Maize with the MCMV infectious clone. Electron microscopy showed that chloroplast photosynthesis in leaves was significantly impeded by the co-infection of MCMV and SCMV. Mitochondria in the MCMV and SCMV co-infected cells were more severely damaged than in MCMV-infected cells. The results of this study provide further insight into the epidemiology of MCMV in China and shed new light on physiological and cytopathological changes related to CLND in Maize.
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first report of Maize Chlorotic Mottle virus infecting sugarcane saccharum officinarum
Plant Disease, 2014Co-Authors: Qi Wang, Xueping ZhouAbstract:The experimental host range of Maize Chlorotic Mottle virus (MCMV) is restricted to the Gramineae (Poaceae) family with Maize as a natural host. However, MCMV has never been found to infect sugarcane (Saccharum officinarum L.) plants in fields. MCMV can cause corn lethal necrosis disease (CLND) resulting from synergistic interaction between this virus and Maize dwarf mosaic virus (MDMV), Wheat streak mosaic virus (WSMV), or Sugarcane mosaic virus (SCMV) (1). MCMV was first found on Maize plants in Yunnan Province in China in 2011 (2), and co-infection of MCMV and SCMV was reported on Maize in Yunnan Province in China in 2013 (1). In January 2013, while surveying MCMV on Maize in Yunnan Province, we found sugarcane planted near an MCMV-infected Maize field with Chlorotic and mosaic viral symptoms. Five symptomatic sugarcane plants were collected and screened for MCMV using a monoclonal antibody-based dot-ELISA (1). MCMV was detected in all five sugarcane samples using this assay. To further confirm the ELI...
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monoclonal antibody based serological methods for Maize Chlorotic Mottle virus detection in china
Journal of Zhejiang University-science B, 2013Co-Authors: Qiang Wang, Yajuan Qian, Huan Liu, Yan Xie, Xueping ZhouAbstract:Maize Chlorotic Mottle virus (MCMV) infects Maize plants and causes significant losses in corn production worldwide. In this study, purified MCMV particles were used as the immunogen to produce monoclonal antibodies (MAbs) and polyclonal antibodies (PAbs). Four murine MAbs (4B8, 8C11, 6F4, and 9G1) against MCMV were obtained through the hybridoma technology. The triple antibody sandwich enzyme-linked immunosorbent assay (TAS-ELISA), dot-immunobinding assay (DIBA), and immunocapture reverse transcription-polymerase chain reaction (IC-RT-PCR) using the MAb 4B8 were then developed for sensitive, specific, and rapid detection of MCMV in fields. MCMV could be detected in infected leaf crude extracts at dilutions of 1:327 680, 1:64 000, and 1:3 276 800 (w/v, g/ml) by TAS-ELISA, DIBA, and IC-RT-PCR, respectively. One hundred and sixty-one Maize field samples showing virus-like symptoms and sixty-nine symptomless Maize field samples from ten different provinces of China were collected and screened for the presence of MCMV using the established serological methods. A phylogenetic tree was constructed based on the full length CP genes and Chinese MCMV isolates formed one branch with Thailand isolates. The detection results demonstrated that MCMV is one of most prevalent viruses infecting Maize in the Yunnan and Sichuan provinces of China.
David Baulcombe - One of the best experts on this subject based on the ideXlab platform.
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Extensive recombination challenges the utility of Sugarcane mosaic virus phylogeny and strain typing
Scientific Reports, 2019Co-Authors: Luke Braidwood, Sebastian Y. Müller, David BaulcombeAbstract:Sugarcane mosaic virus (SCMV) is distributed worldwide and infects three major crops: sugarcane, Maize, and sorghum. The impact of SCMV is increased by its interaction with Maize Chlorotic Mottle virus which causes the synergistic Maize disease Maize lethal necrosis. Here, we characterised Maize lethal necrosis-infected Maize from multiple sites in East Africa, and found that SCMV was present in all thirty samples. This distribution pattern indicates that SCMV is a major partner virus in the East African Maize lethal necrosis outbreak. Consistent with previous studies, our SCMV isolates were highly variable with several statistically supported recombination hot- and cold-spots across the SCMV genome. The recombination events generate conflicting phylogenetic signals from different fragments of the SCMV genome, so it is not appropriate to group SCMV genomes by simple similarity.
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Maize Chlorotic Mottle virus exhibits low divergence between differentiated regional sub-populations
Scientific Reports, 2018Co-Authors: Luke Braidwood, Alberto Bressan, Diego F. Quito-avila, Darlene Cabanas, Anne Wangai, David BaulcombeAbstract:Maize Chlorotic Mottle virus has been rapidly spreading around the globe over the past decade. The interactions of Maize Chlorotic Mottle virus with Potyviridae viruses causes an aggressive synergistic viral condition - Maize lethal necrosis, which can cause total yield loss. Maize production in sub-Saharan Africa, where it is the most important cereal, is threatened by the arrival of Maize lethal necrosis. We obtained Maize Chlorotic Mottle virus genome sequences from across East Africa and for the first time from Ecuador and Hawaii, and constructed a phylogeny which highlights the similarity of Chinese to African isolates, and Ecuadorian to Hawaiian isolates. We used a measure of clustering, the adjusted Rand index, to extract region-specific SNPs and coding variation that can be used for diagnostics. The population genetics analysis we performed shows that the majority of sequence diversity is partitioned between populations, with diversity extremely low within China and East Africa.
