Papers by Jesus Angel Sanchez-Navarro
Frontiers in Microbiology
Frontiers in Microbiology
European Journal of Plant Pathology
Frontiers in microbiology, 2018
Plant viruses are still one of the main contributors to economic losses in agriculture. It has be... more Plant viruses are still one of the main contributors to economic losses in agriculture. It has been estimated that plant viruses can cause as much as 50 billion euros loss worldwide, per year. This situation may be worsened by recent climate change events and the associated changes in disease epidemiology. Reliable and early detection methods are still one of the main and most effective actions to develop control strategies for plant viral diseases. During the last years, considerable progress has been made to develop tools with high specificity and low detection limits for use in the detection of these plant pathogens. Time and cost reductions have been some of the main objectives pursued during the last few years as these increase their feasibility for routine use. Among other strategies, these objectives can be achieved by the simultaneous detection and (or) identification of several viruses in a single assay. Nucleic acid-based detection techniques are especially suitable for th...
Phytopathology, Jan 12, 2018
The use of a unique riboprobe named `polyprobe´, carrying partial sequences of different plant vi... more The use of a unique riboprobe named `polyprobe´, carrying partial sequences of different plant viruses or viroids fused in tandem, has permitted the polyvalent detection of up to ten different pathogens by using a non-radioactive molecular hybridization procedure. In the present analysis, we have developed a unique polyprobe with the capacity to detect all members of the Potyvirus genus, which we have named 'genus-probe' (GP). To do this, we have exploited the capacity of the molecular hybridization assay to cross-hybridize with related sequences by reducing the hybridization temperature. We observed that sequences showing a percentage similarity of 68% or higher, could be detected with the same probe by hybridizing at 50-55ºC, with a detection limit of picograms of viral RNA comparable to the specific individual probes. According to this, we developed several polyvalent polyprobes, containing 3, 5 or 7 different 500-nucleotide fragments of a conserved region of the NIb gene...
Virus research, Jan 21, 2018
Genes orthologous to the 30K-superfamily of movement proteins (MP) from plant viruses have been r... more Genes orthologous to the 30K-superfamily of movement proteins (MP) from plant viruses have been recently discovered by bioinformatics analyses as integrated elements in the genome of most vascular plants. However, their functional relevance for plants is still unclear. Here, we undertake some preliminary steps into the functional characterization of one of these putative MP genes found in Arabidopsis thaliana. We found that the AtMP gene is expressed at different stages of the plant development, with accumulation being highest in flowers but lowest in mature siliques. We also found down-regulation of the gene may result in a small delay in plant development and in an exacerbation of the negative effect of salinity in germination efficiency. We have also explored whether changes in expression of the endogenous AtMP have any effect on susceptibility to infection with several viruses, and found that the infectivity of tobacco rattle tobravirus was strongly dependent on the expression o...
Proceedings of the National Academy of Sciences
N6-methyladenosine (m6A) is an internal, reversible nucleotide modification that constitutes an i... more N6-methyladenosine (m6A) is an internal, reversible nucleotide modification that constitutes an important regulatory mechanism in RNA biology. Unlike mammals and yeast, no component of the m6A cellular machinery has been described in plants at present. m6A has been identified in the genomic RNAs of diverse mammalian viruses and, additionally, viral infection was found to be modulated by the abundance of m6A in viral RNAs. Here we show that the Arabidopsis thaliana protein atALKBH9B (At2g17970) is a demethylase that removes m6A from single-stranded RNA molecules in vitro. atALKBH9B accumulates in cytoplasmic granules, which colocalize with siRNA bodies and associate with P bodies, suggesting that atALKBH9B m6A demethylase activity could be linked to mRNA silencing and/or mRNA decay processes. Moreover, we identified the presence of m6A in the genomes of two members of the Bromoviridae family, alfalfa mosaic virus (AMV) and cucumber mosaic virus (CMV). The demethylation activity of at...
One of the most intriguing questions in evolutionary virology is why multipartite viruses exist. ... more One of the most intriguing questions in evolutionary virology is why multipartite viruses exist. Several hypotheses suggest benefits that outweigh the obvious costs associated with encapsidating each genomic segment into a different viral particle: reduced transmission efficiency and segregation of coadapted genes. These putative advantages range from increasing genome size despite high mutation rates (i.e., escaping from Eigen’s paradox), faster replication, more efficient selection resulting from segment reassortment during mixed infections, or enhanced virion stability and cell-to-cell movement. However, empirical support for these hypotheses is scarce. A more recent hypothesis is that segmentation represents a simple and robust mechanism to regulate gene copy number and, thereby, gene expression. According to this hypothesis, the ratio at which different segments exist during infection of individual hosts should represent a stable situation and would respond to the varying neces...
EI "torrao" es una enfermedad presente en ouestro país desde 2001, que sigue presentándose en cad... more EI "torrao" es una enfermedad presente en ouestro país desde 2001, que sigue presentándose en cada campaña de tomate con mayor o menor incidencia según el año. Las plantas afectadas muestran necrosis en la parte basal de los foliolos yue puede evolucionar a cribado, manchas longitudinales en los peciolos y manchas necróticas en fruto, yue terminan por rajarlo. EI presente trabajo es la continuación del publicudo en el número 32 de esta revista titulado "Necrosis del tomate: "torraó' o cribadó' y surge de los resultados obtenidos tras la reciente publicación de la identiticacicín y carac[erización del nuevo virus "Tnmato torrado ^^rru ► ' (ToTV) como agente implicado en la enfermedad conocida como "torrao". En este estudio se seleccionaron 94 muestrati procedentes de prospecciones realizadas en invernaderos de Murcia durante los años 2(H)3 a 2006. La aplicación RT-PCR e hibridación molecular para la detección de ToTV ha permitido detectar la presencia de esta nueva virosis en 87 de las muestras unalizadas. En 83 de ellas, se encontró la preseneia conjunta de este nuevo virus con el Pepino mati^aic c^irus (PepMV), mayoritariamente con el aislado tipo Chileno 2(Accesión number: DQ00095). Se plantean nuevos estudios para determinar la implicacicín de ambos virus, ToTV y PepMV, en el desarrollo det síndrome conocido como "torrao" del tomate.
Methods in molecular biology (Clifton, N.J.), 2009
Multiplex Polymerase Chain Reaction (PCR) can be used for the simultaneous detection of plant vir... more Multiplex Polymerase Chain Reaction (PCR) can be used for the simultaneous detection of plant viruses. Multiple primer pairs or polyvalent primer pairs can be used to detect and identify several viruses in a single PCR.
Virology, 2006
RNA 3 of Alfalfa mosaic virus (AMV) encodes the movement protein (MP) and coat protein (CP). Chim... more RNA 3 of Alfalfa mosaic virus (AMV) encodes the movement protein (MP) and coat protein (CP). Chimeric RNA 3 with the AMV MP gene replaced by the corresponding MP gene of Prunus necrotic ringspot virus, Brome mosaic virus, Cucumber mosaic virus or Cowpea mosaic virus efficiently moved from cell-to-cell only when the expressed MP was extended at its C-terminus with the C-terminal 44 amino acids of AMV MP. MP of Tobacco mosaic virus supported the movement of the chimeric RNA 3 whether or not the MP was extended with the C-terminal AMV MP sequence. The replacement of the CP gene in RNA 3 by a mutant gene encoding a CP defective in virion formation did not affect cell-to-cell transport of the chimera's with a functional MP. A GST pull-down technique was used to demonstrate for the first time that the C-terminal 44 amino acids of the MP of a virus belonging to the family Bromoviridae interact specifically with AMV virus particles. Together, these results demonstrate that AMV RNA 3 can...
The Journal of general virology, 2001
Alfalfa mosaic virus (AMV) and Prunus necrotic ringspot virus (PNRSV) belong to the genera ALFAMO... more Alfalfa mosaic virus (AMV) and Prunus necrotic ringspot virus (PNRSV) belong to the genera ALFAMOVIRUS: and ILARVIRUS:, respectively, of the family BROMOVIRIDAE: Initiation of infection by AMV and PNRSV requires binding of a few molecules of coat protein (CP) to the 3' termini of the inoculum RNAs and the CPs of the two viruses are interchangeable in this early step of the replication cycle. CIS:-acting sequences in PNRSV RNA 3 that are recognized by the AMV replicase were studied in in vitro replicase assays and by inoculation of AMV-PNRSV RNA 3 chimeras to tobacco plants and protoplasts transformed with the AMV replicase genes (P12 plants). The results showed that the AMV replicase recognized the promoter for minus-strand RNA synthesis in PNRSV RNA 3 but not the promoter for plus-strand RNA synthesis. A chimeric RNA with PNRSV movement protein and CP genes accumulated in tobacco, which is a non-host for PNRSV.
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Papers by Jesus Angel Sanchez-Navarro