scholarly journals Mutations in Rice yellow mottle virus Polyprotein P2a Involved in RYMV2 Gene Resistance Breakdown

2016 ◽  
Vol 7 ◽  
Author(s):  
Agnès Pinel-Galzi ◽  
Christine Dubreuil-Tranchant ◽  
Eugénie Hébrard ◽  
Cédric Mariac ◽  
Alain Ghesquière ◽  
...  
Keyword(s):  
Mottle Virus ◽  
Rice Yellow Mottle Virus ◽  
Resistance Breakdown ◽  
Yellow Mottle ◽  
Virus Polyprotein

scholarly journals Alternative mutational pathways, outside the VPg, of rice yellow mottle virus to overcome eIF(iso)4G-mediated rice resistance under strong genetic constraints

2014 ◽  
Vol 95 (1) ◽  
pp. 219-224 ◽  
Author(s):  
Nils Poulicard ◽  
Agnès Pinel-Galzi ◽  
Denis Fargette ◽  
Eugénie Hébrard
Keyword(s):  
Infectious Clone ◽  
A Priori ◽  
Mottle Virus ◽  
Rice Yellow Mottle Virus ◽  
Genetic Constraints ◽  
Resistance Breakdown ◽  
Yellow Mottle ◽  
Viral Accumulation ◽  
Overlapping Region

The adaptation of rice yellow mottle virus (RYMV) to rymv1-mediated resistance has been reported to involve mutations in the viral genome-linked protein (VPg). In this study, we analysed several cases of rymv1-2 resistance breakdown by an isolate with low adaptability. Surprisingly, in these rarely occurring resistance-breaking (RB) genotypes, mutations were detected outside the VPg, in the ORF2a/ORF2b overlapping region. The causal role of three mutations associated with rymv1-2 resistance breakdown was validated via directed mutagenesis of an infectious clone. In resistant plants, these mutations increased viral accumulation as efficiently as suboptimal RB mutations in the VPg. Interestingly, these mutations are located in a highly conserved, but unfolded, domain. Altogether, our results indicate that under strong genetic constraints, a priori unfit genotypes can follow alternative mutational pathways, i.e. outside the VPg, to overcome rymv1-2 resistance.

scholarly journals Identification of a Hypervirulent Pathotype of Rice yellow mottle virus: A Threat to Genetic Resistance Deployment in West-Central Africa

2018 ◽  
Vol 108 (2) ◽  
pp. 299-307 ◽  
Author(s):  
Eugénie Hébrard ◽  
Agnès Pinel-Galzi ◽  
Aderonke Oludare ◽  
Nils Poulicard ◽  
Jamel Aribi ◽  
...  
Keyword(s):  
High Resistance ◽  
Infectious Clone ◽  
Genetic Resistance ◽  
Central Africa ◽  
Mottle Virus ◽  
Rice Yellow Mottle Virus ◽  
West Central ◽  
Adaptive Processes ◽  
Resistance Breakdown ◽  
Yellow Mottle

Rice yellow mottle virus (RYMV) causes high losses to rice production in Africa. Several sources of varietal high resistance are available but the emergence of virulent pathotypes that are able to overcome one or two resistance alleles can sometimes occur. Both resistance spectra and viral adaptability have to be taken into account to develop sustainable rice breeding strategies against RYMV. In this study, we extended previous resistance spectrum analyses by testing the rymv1-4 and rymv1-5 alleles that are carried by the rice accessions Tog5438 and Tog5674, respectively, against isolates that are representative of RYMV genetic and pathogenic diversity. Our study revealed a hypervirulent pathotype, named thereafter pathotype T′, that is able to overcome all known sources of high resistance. This pathotype, which is spatially localized in West-Central Africa, appears to be more abundant than previously suspected. To better understand the adaptive processes of pathotype T′, molecular determinants of resistance breakdown were identified via Sanger sequencing and validated through directed mutagenesis of an infectious clone. These analyses confirmed the key role of convergent nonsynonymous substitutions in the central part of the viral genome-linked protein to overcome RYMV1-mediated resistance. In addition, deep-sequencing analyses revealed that resistance breakdown does not always coincide with fixed mutations. Actually, virulence mutations that are present in a small proportion of the virus population can be sufficient for resistance breakdown. Considering the spatial distribution of RYMV strains in Africa and their ability to overcome the RYMV resistance genes and alleles, we established a resistance-breaking risk map to optimize strategies for the deployment of sustainable and resistant rice lines in Africa.

scholarly journals The rice yellow mottle virus P1 protein exhibits dual functions to suppress and activate gene silencing

2010 ◽  
Vol 61 (3) ◽  
pp. 371-382 ◽  
Author(s):  
Séverine Lacombe ◽  
Martine Bangratz ◽  
Florence Vignols ◽  
Christophe Brugidou
Keyword(s):  
Gene Silencing ◽  
Mottle Virus ◽  
Rice Yellow Mottle Virus ◽  
Yellow Mottle ◽  
Activate Gene ◽  
Dual Functions

Molecular epidemiology of the RNA satellite of Rice yellow mottle virus in Africa

2003 ◽  
Vol 148 (9) ◽  
pp. 1721-1733 ◽  
Author(s):  
A. Pinel ◽  
Z. Abubakar ◽  
O. Traor� ◽  
G. Konat� ◽  
D. Fargette
Keyword(s):  
Molecular Epidemiology ◽  
Mottle Virus ◽  
Rice Yellow Mottle Virus ◽  
Yellow Mottle

scholarly journals Synthesis of an infectious full-length cDNA clone of rice yellow mottle virus andmutagenesis of the coat protein

Virology ◽  
1995 ◽  
Vol 206 (1) ◽  
pp. 108-115 ◽  
Author(s):  
C. Brugidou ◽  
C. Holt ◽  
M. Ngon A Yassi ◽  
S. Zhang ◽  
R. Beachy ◽  
...  
Keyword(s):  
Coat Protein ◽  
Cdna Clone ◽  
Full Length ◽  
Mottle Virus ◽  
Rice Yellow Mottle Virus ◽  
Full Length Cdna ◽  
Yellow Mottle

scholarly journals The Genetic Basis of High Resistance to Rice Yellow Mottle Virus (RYMV) in Cultivars of Two Cultivated Rice Species

Plant Disease ◽  
1999 ◽  
Vol 83 (10) ◽  
pp. 931-935 ◽  
Author(s):  
M. N. Ndjiondjop ◽  
L. Albar ◽  
D. Fargette ◽  
C. Fauquet ◽  
A. Ghesquière
Keyword(s):  
Genetic Basis ◽  
Virus Isolate ◽  
Mottle Virus ◽  
F1 Hybrids ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rice Yellow Mottle Virus ◽  
Recessive Resistance ◽  
Cultivated Rice ◽  
Recessive Resistance Gene ◽  
Yellow Mottle

Three cultivars of Oryza sativa (IR64, Azucena, and Gigante) and four cultivars of O. glaberrima (Tog5681, Tog5673, CG14, and SG329) were evaluated for their resistance to two isolates of rice yellow mottle virus (RYMV) by enzyme-linked immunosorbent assay (ELISA) and symptomatology. Cultivars Tog5681 and Gigante were highly resistant, and no symptoms were observed when either virus isolate was inoculated at 10 or 20 days postgermination and assayed by ELISA at 7, 14, 22, 35, 50, or 64 days postinoculation. Azucena showed a partial resistance, whereas the other cultivars were susceptible. Symptom appearance was associated with increase in ELISA absorbance in the systemically infected leaves. The best discrimination among the cultivars occurred when the plants were inoculated at 10 days postgermination. Crosses were made between the highly resistant (Gigante and Tog5681) and the susceptible (IR64) cultivars to determine the genetic basis of resistance to RYMV. Evaluation of F1 hybrids and interspecific progenies, as well as the segregation of resistance in F2 and F3 lines of the IR64 × Gigante cross, provided results consistent with the presence of a single recessive resistance gene common to Tog5681 and Gigante.

scholarly journals Full-Length Genome Sequences of Recombinant and Nonrecombinant Sympatric Strains of Rice yellow mottle virus from Western Kenya

2018 ◽  
Vol 6 (8) ◽  
Author(s):  
Antony Kigaru Adego ◽  
Nils Poulicard ◽  
Agnès Pinel-Galzi ◽  
Benard Mukoye ◽  
Denis Fargette ◽  
...  
Keyword(s):  
Full Length ◽  
Mottle Virus ◽  
Rice Yellow Mottle Virus ◽  
Genome Sequences ◽  
Western Kenya ◽  
Yellow Mottle ◽  
Full Length Genome

ABSTRACT Five isolates of Rice yellow mottle virus from western Kenya were fully sequenced. One isolate of strain S4lv had been collected in 1966. Two isolates belonged to the emerging strain S4ug recently described in Uganda. Two isolates collected in 2012 are putative recombinants between the S4lv and S4ug strains.

Rice Yellow Mottle Virus (Solemoviridae)

2020 ◽  
Author(s):  
Eugénie Hébrard ◽  
Nils Poulicard ◽  
Mbolarinosy Rakotomalala
Keyword(s):  
Mottle Virus ◽  
Rice Yellow Mottle Virus ◽  
Yellow Mottle
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