Search results for "viru"
showing 10 items of 5513 documents
The transcriptomics of an experimentally evolved plant-virus interaction
2015
[EN] Models of plant-virus interaction assume that the ability of a virus to infect a host genotype depends on the matching between virulence and resistance genes. Recently, we evolved tobacco etch potyvirus (TEV) lineages on different ecotypes of Arabidopsis thaliana, and found that some ecotypes selected for specialist viruses whereas others selected for generalists. Here we sought to evaluate the transcriptomic basis of such relationships. We have characterized the transcriptomic responses of five ecotypes infected with the ancestral and evolved viruses. Genes and functional categories differentially expressed by plants infected with local TEV isolates were identified, showing heterogene…
Clonal populations of Clavibacter michiganensis subsp michiganensis are responsible for the outbreaks of bacterial canker in greenhouse tomatoes in I…
2015
Clavibacter michiganensis subsp. michiganensis (Cmm) strains, collected in greenhouses from 17 farms during tomato bacterial canker outbreaks occurring between 2005 and 2008 in Sicily, were analysed by a multiphasic approach. Population studies were conducted to investigate the possible sources of inocula. Cmm strains were characterized by PCR assays targeting virulence genes, fingerprinting techniques, metabolic profiles and virulence. These strains were comparatively analysed with Cmm strains isolated in other parts of Italy over a period of 15 years. Chromosomal genes encoding virulence determinants tomA, ppaA, chpC, and the plasmid-encoded genes pat-1 and celA were detected by PCR in al…
Loop Mediated Isothermal Amplification: Principles and Applications in Plant Virology
2020
In the last decades, the evolution of molecular diagnosis methods has generated different advanced tools, like loop-mediated isothermal amplification (LAMP). Currently, it is a well-established technique, applied in different fields, such as the medicine, agriculture, and food industries, owing to its simplicity, specificity, rapidity, and low-cost efforts. LAMP is a nucleic acid amplification under isothermal conditions, which is highly compatible with point-of-care (POC) analysis and has the potential to improve the diagnosis in plant protection. The great advantages of LAMP have led to several upgrades in order to implement the technique. In this review, the authors provide an overview r…
Tomato Brown Rugose Fruit Virus: Seed Transmission Rate and Efficacy of Different Seed Disinfection Treatments
2020
Tomato brown rugose fruit virus (ToBRFV) is a highly infectious virus, that is becoming a threat to tomato production worldwide. In this work we evaluated the localization of ToBRFV particles in tomato seeds, its seed transmission rate and efficacy of disinfection, and the effects of different thermal- and chemical-based treatments on ToBRFV-infected seeds&rsquo
Identifying Early Warning Signals for the Sudden Transition from Mild to Severe Tobacco Etch Disease by Dynamical Network Biomarkers
2019
This article belongs to the Special Issue The Complexity of the Potyviral Interaction Network.
Spatially-induced nestedness in a neutral model of phage-bacteria networks
2017
[EN] Ecological networks, both displaying mutualistic or antagonistic interactions, seem to share common structural traits: the presence of nestedness and modularity. A variety of model approaches and hypothesis have been formulated concerning the significance and implications of these properties. In phage-bacteria bipartite infection networks, nestedness seems to be the rule in many different contexts. Modeling the coevolution of a diverse virus¿host ensemble is a difficult task, given the dimensionality and multi parametric nature of a standard continuous approximation. Here, we take a different approach, by using a neutral, toy model of host¿phage interactions on a spatial lattice. Each …
Successive Losses of Central Immune Genes Characterize the Gadiformes' Alternate Immunity.
2016
Great genetic variability among teleost immunomes, with gene losses and expansions of central adaptive and innate components, has been discovered through genome sequencing over the last few years. Here, we demonstrate that the innate Myxovirus resistance gene (Mx) is lost from the ancestor of Gadiformes and the closely related Stylephorus chordatus, thus predating the loss of Major Histocompatibility Complex class II (MHCII) in Gadiformes. Although the functional implication of Mx loss is still unknown, we demonstrate that this loss is one of several ancient events appearing in successive order throughout the evolution of teleost immunity. In particular, we find that the loss of Toll-like r…
Local adaptation of plant viruses: lessons from experimental evolution.
2016
[EN] For multihost pathogens, adaptation to multiple hosts has important implications for both applied and basic research. At the applied level, it is one of the main factors determining the probability and severity of emerging disease outbreaks. At the basic level, it is thought to be a key mechanism for the maintenance of genetic diversity both in host and pathogen species. In recent years, a number of evolution experiments have assessed the fate of plant virus populations replicating within and adapting to one single or to multiple hosts species. A first group of these experiments tackled the existence of trade-offs in fitness and virulence for viruses evolving either within a single hos…
The nucleotide sequence of a recombinant tomato yellow leaf curl virus strain frequently detected in Sicily isolated from tomato plants carrying the …
2017
In July 2016, an aggressive syndrome of tomato yellow leaf curl disease was reported in Sicily in tomato plants carrying the Ty-1 resistance gene. A total of 34 samples were collected and analyzed. Twenty-seven out of the 34 samples analyzed appeared to contain only recombinant molecules. One full sequence was obtained after cloning. Alignments and plot similarity analysis showed that the genome of the recombinant, named TYLCV-IL[IT:Sic23:16], was mostly derived from tomato yellow leaf curl virus (TYLCV), with a small region of 132 nucleotides in the non-coding region between the stem-loop and the start of the V2 ORF replaced by 124 nucleotides derived from a virus of a different species, t…
EVOLUTIONARY DYNAMICS OF FITNESS RECOVERY FROM THE DEBILITATING EFFECTS OF MULLER'S RATCHET.
1998
The great adaptability shown by RNA viruses is a consequence of their high mutation rates. The evolution of fitness in a severely debilitated, clonal population of the nonsegmented ribovirus vesicular stomatitis virus (VSV) has been compared under five different demographic regimes, ranging from severe serial bottleneck passages (one virion) to large population passages (105 virions or more) under similar environmental conditions (cell culture type and temperature). No matter how small the bottleneck, the fitness of the evolved populations was always higher than the fitness of the starting population; this result is clearly different from that previously reported for viruses with higher fit…