The family Solemoviridae includes viruses with icosahedral particles (26–34 nm in diameter) assembled on T =3 symmetry a 4–6 kb positive-sense, monopartite, polycistronic RNA genome. Transmission of members the genera Sobemovirus and Polemovirus occurs via mechanical wounding, vegetative propagation, insect vectors or abiotically through soil; Polerovirus Enamovirus are transmitted by specific aphids. Most solemoviruses have narrow host range. This is summary International Committee Taxonomy...

We report here evidence of the role that isoform eukaryotic translation initiation factor 4G (eIF(iso)4G) plays in naturally occurring resistance plant/virus interactions. A genetic and physical mapping approach was developed to isolate Rymv1 locus controlling high recessive Rice yellow mottle virus (RYMV) rice (Oryza sativa) variety Gigante. The mapped a 160-kb interval containing gene from eIF(iso)4G family. stable transformation resistant line with cDNA this gene, derived susceptible...

Hundreds of species plant viruses, many them economically important, are transmitted by noncirculative vector transmission (acquisition attachment virions to mouthparts and inoculation subsequent release), but virus receptors within the remain elusive. Here we report evidence for existence, precise location, chemical nature first receptor a virus, cauliflower mosaic in its insect vector. Electron microscopy revealed virus-like particles previously undescribed anatomical zone at extreme tip...

A novel dwarf and twisting syndrome first observed on rice in Nghe An Province, Vietnam, 2009 has spread rapidly to the other 19 provinces of North Central Vietnam. Infected plants showed stunting, darkening leaves, leaf tips, splitting margins. At a later stage, white waxy enations that eventually turned black were underside blades, sheaths, culms. The disease also infected maize after was harvested. stunted dark green with small along minor veins back leaves. agent now been identified as...

Fourteen isolates of Rice yellow mottle virus (RYMV) were selected as representative the genetic variability in Africa from a total set 320 serologically typed or partially sequenced. The 14 fully sequenced and analyzed together with two previously reported sequences. RYMV had genomic organization similar to that Cocksfoot sobemovirus. average nucleotide diversity among 16 was 7%, maximum between any 10%. A strong conservative selection apparent on both synonymous nonsynonymous...

The adaptation of Rice yellow mottle virus (RYMV) to recessive resistance mediated by the rymv1-2 allele has been reported as a model study emergence and evolution virulent variants. virulence factors have identified eukaryotic translation initiation factor eIF(iso)4G1 viral genome-linked protein (VPg), respectively, but molecular mechanisms involved in their interaction are still unknown. In this study, we demonstrated direct between RYMV VPg central domain rice both vitro, using...

Prediction of pathogen emergence is an important field research, both in human health and agronomy. Most studies have focused on the ecological or anthropic factors involved rather than role intrinsic properties. The capacity pathogens to infect a large set host species, i.e. possess range breadth (HRB), tightly linked their propensity. Using extensive plant virus database, we found that four traits related genome transmission properties were strongly robustly HRB. Broader ranges observed...

Co-occurrence of multiple diseases and co-infection individual plants by various pathogens have potential epidemiological evolutionary implications. Based on previous information the co-occurrence rice yellow mottle disease (caused virus, RYMV) bacterial leaf streak (BLS, due to Xanthomonas oryzae pv. oryzicola, Xoc) in Burkina Faso, experimental evidence interactions between causing these two diseases, we aimed monitor more intensively farmers fields. To this purpose, selected fields...

Interactions between Cauliflower mosaic virus (CaMV) and its aphid vector are regulated by the viral protein P2, which binds to stylets, P3, bridges P2 virions. By using baculovirus expression of electron microscopy, surface plasmon resonance, affinity chromatography, transmission assays, we demonstrate that P3 must be previously bound virions in order attachment will allow CaMV. We also show a P2:P3 complex exists absence but is nonfunctional transmission. Hence, unlike cannot sequentially...

VPgs are viral proteins linked to the 5' end of some genomes. Interactions between several and eukaryotic translation initiation factors eIF4Es critical for plant infection. However, not restricted phytoviruses, being also involved in genome replication protein animal viruses. To date, structural data still limited small picornaviral VPgs. Recently three phytoviral were shown be natively unfolded proteins. In this paper, we report bacterial expression, purification biochemical...

The mechanisms of evolution plant viruses are being unraveled, yet the timescale their remains an enigma. To address this critical issue, divergence time at intra- and inter-specific levels was assessed. most recent common ancestor (TMRCA) Rice yellow mottle virus (RYMV; genus Sobemovirus) calculated by a Bayesian coalescent analysis coat protein sequences 253 isolates collected between 1966 2006 from all over Africa. It is inferred that RYMV diversified approximately 200 years ago in...

The rymv1-2 and rymv1-3 alleles of the RYMV1 resistance to Rice yellow mottle virus (RYMV), coded by an eIF(iso)4G1 gene, occur in a few cultivars Asiatic (Oryza sativa) African (O. glaberrima) rice species, respectively. most salient feature breaking (RB) process is converse genetic barrier breakdown. This specificity modulated amino acid (glutamic vs. threonine) at codon 49 Viral Protein genome-linked (VPg), position which adjacent virulence codons 48 52. Isolates with glutamic (E) do not...

Intrinsic disorder (ID) in proteins is defined as a lack of stable structure physiological conditions. Intrinsically disordered regions (IDRs) are highly abundant some RNA virus proteomes. Low topological constraints exerted on IDRs expected to buffer the effect numerous deleterious mutations and could be related remarkable adaptive potential viruses overcome resistance their host. To experimentally test this hypothesis natural pathosystem, set four variants Potato Y (PVY; Potyvirus genus)...

Simultaneous infection of a single plant by various pathogen species is increasingly recognized as an important modulator host resistance and driver evolution. Because plants in agro-ecosystems are the target multitude pathogenic microbes, co-infection could be frequent, consequently to consider. This particularly true for rapidly intensifying crops, such rice Africa. study investigated potential interactions between pathogens causing two major diseases Africa: Rice yellow mottle virus...

(RYMV) in Madagascar Island provides an opportunity to study the spread of a plant virus disease after relatively recent introduction large and isolated country with heterogeneous host landscape ecology. Here, we take advantage field survey data on occurrence RYMV throughout dating back 1970s, genetic from ninety-four isolates collected since 1989 most regions reconstruct epidemic history. We find that Malagasy belong unique recombinant strain likely entered through long-distance eastern...

Abstract Phylogeography of Rice yellow mottle virus (RYMV) was reconstructed from the coat protein gene sequences a selection 173 isolates 14 countries mainland Africa where disease occurred and full 16 representative isolates. Genetic variation linked to geographical distribution not host species as wild rice always clustered with cultivated same region. associated agro‐ecology, viral interference insect vector species. Distinct RYMV lineages in East, Central West Africa, although African...

The recessive gene rymv-1, responsible for the high resistance of Oryza sativa 'Gigante' to Rice yellow mottle virus (genus Sobemovirus), was overcome by variant CI4*, which emerged after serial inoculations non-resistance-breaking (nRB) isolate CI4. By comparison full-length sequences CI4 and a non-synonymous mutation identified at position 1729, localized in putative VPg domain, an assay developed based on this single-nucleotide polymorphism. G1729T detected as early first passage...

ABSTRACT The rate of evolution an RNA plant virus has never been estimated using temporally spaced sequence data, by contrast to the information available on increasing range animal viruses. Accordingly, Rice yellow mottle (RYMV) was calculated from sequences coat protein gene isolates collected rice over a 40-year period in different parts Africa. RYMV pairwise distance linear regression five phylogeographically defined groups comprising total 135 isolates. It further assessed 253 all...

The diversity of a highly variable RNA plant virus was considered to determine the range virulence substitutions, evolutionary pathways virulence, and whether intraspecific modulates propensity. In all, 114 isolates representative genetic geographic Rice yellow mottle (RYMV) in Africa were inoculated several cultivars with eIF(iso)4G-mediated Rymv1-2 resistance. Altogether, 41 virulent variants generated from ten wild analyzed. Nonconservative amino acid replacements at five positions...

Rice yellow mottle virus (RYMV) reaches a high content in rice, is genetically highly variable and evolves rapidly. Nevertheless, only small proportion of isolates overcome rymv1-2 rice resistance by mutations the VPg (viral protein genome-linked). The accumulation rates wild-type (WT) resistance-breaking (RB) genotypes E- T-pathotypes RYMV, with average low virulence, respectively, were assessed. By quantitative reverse transcriptase-polymerase chain reaction, it was shown that: (i)...

Several ethylene-response factor (ERF) transcription factors are believed to play a crucial role in the activation of plant defence responses, but little is known about relationships between diversity this family and functions groups or individual ERFs process. In study, 200 ERF genes from unigene cotton database were identified. Conserved amino acid residues phylogeny reconstruction using AP2 conserved domain suggest that classification into 10 major used for Arabidopsis rice applicable...

Rice yellow mottle virus (RYMV) is one of the major diseases rice in Africa. The high resistance Oryza glaberrima Tog7291 accession involves a null allele RYMV2 gene, whose ortholog Arabidopsis, CPR5, transmembrane nucleoporin involved effector-triggered immunity. To optimize field deployment gene and improve its durability, which often weak point varietal resistance, we analyzed efficiency toward RYMV isolates representing genetic diversity molecular basis breakdown. was highly variable...