scholarly journals Pathogenic Variation and Occurrence of Multiple Resistance-Breaking <i>Rice yellow mottle virus</i> Strains in Tanzania

2017 ◽  
Vol 08 (08) ◽  
pp. 1820-1841 ◽  
Author(s):  
Judith Hubert ◽  
Herman J. F. Lyimo ◽  
Ashura Luzi-Kihupi
Keyword(s):  
Mottle Virus ◽  
Multiple Resistance ◽  
Rice Yellow Mottle Virus ◽  
Resistance Breaking ◽  
Pathogenic Variation ◽  
Yellow Mottle

scholarly journals Emergence of a resistance-breaking isolate of Rice yellow mottle virus during serial inoculations is due to a single substitution in the genome-linked viral protein VPg

2006 ◽  
Vol 87 (5) ◽  
pp. 1369-1373 ◽  
Author(s):  
Eugénie Hébrard ◽  
Agnès Pinel-Galzi ◽  
Anne Bersoult ◽  
Christelle Siré ◽  
Denis Fargette
Keyword(s):  
Infectious Clone ◽  
Recessive Gene ◽  
Mottle Virus ◽  
Rice Yellow Mottle Virus ◽  
Recessive Resistance ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Resistance Breaking ◽  
The Family ◽  
Yellow Mottle

The recessive gene rymv-1, responsible for the high resistance of Oryza sativa ‘Gigante’ to Rice yellow mottle virus (genus Sobemovirus), was overcome by the variant CI4*, which emerged after serial inoculations of the non-resistance-breaking (nRB) isolate CI4. By comparison of the full-length sequences of CI4 and CI4*, a non-synonymous mutation was identified at position 1729, localized in the putative VPg domain, and an assay was developed based on this single-nucleotide polymorphism. The mutation G1729T was detected as early as the first passage in resistant plants and was found in all subsequent passages. Neither reversion nor any additional mutation was observed. The substitution G1729T, introduced by mutagenesis into the VPg of an nRB infectious clone, was sufficient to induce symptoms in uninoculated leaves of O. sativa ‘Gigante’. This is the first evidence that VPg is a virulence factor in plants with recessive resistance against viruses outside the family Potyviridae.

scholarly journals Occurrence of Resistance-Breaking Isolates of Rice yellow mottle virus in West and Central Africa

Plant Disease ◽  
2006 ◽  
Vol 90 (3) ◽  
pp. 259-263 ◽  
Author(s):  
Oumar Traoré ◽  
Agnès Pinel ◽  
Eugénie Hébrard ◽  
Mawena Y. Dieudonné Gumedzoé ◽  
Denis Fargette ◽  
...  
Keyword(s):  
Central Africa ◽  
Mottle Virus ◽  
Rice Yellow Mottle Virus ◽  
Serological Tests ◽  
High Frequencies ◽  
Plant Infection ◽  
Resistance Breaking ◽  
West And Central Africa ◽  
Yellow Mottle ◽  
Savannah Zone

Rice yellow mottle virus (RYMV) is the most important rice-infecting virus in Africa. Highly resistant rice (Oryza spp.) cultivars Gigante and Tog5681 were challenged with virus isolates from five countries of the west and central African Sudano-savannah zone in order to investigate the occurrence and prevalence of resistance-breaking (RB) isolates. High resistance was overcome by 38.6% of the isolates. RB isolates could be divided into three main pathogenic groups. Isolates of the first group (17.5%) and of the second group (16.4%) were able to break down the resistance of Gigante only and of Tog5681 only, respectively. Resistance in both cultivars was overcome simultaneously by isolates of the third group (4.7%). In each group, some isolates induced symptoms, whereas plant infection by others was evidenced only by serological tests. RB isolates occurred in all five countries with varying frequencies (19 to 57%). The wide geographical distribution and high frequencies of RB isolates represent a high risk for the durability of resistance to RYMV in the Sudano-savannah zone.

scholarly journals Occurrence of rice yellow mottle virus resistance breaking isolates in lowland catchment zones of Uganda

1970 ◽  
Vol 29 (3) ◽  
pp. 383-400
Author(s):  
I. Ramathani ◽  
S.B. Mukasa ◽  
T. Alicai ◽  
S. Nanyiti ◽  
J. Lamo
Keyword(s):  
Virus Disease ◽  
Lowland Rice ◽  
Mottle Virus ◽  
Post Inoculation ◽  
Rice Yellow Mottle Virus ◽  
Symptom Development ◽  
Rt Pcr ◽  
Resistance Breaking ◽  
Catchment Areas ◽  
Yellow Mottle

Rice (Oryza spp; 2n=24.) production in Uganda and Africa in general, is seriously threatened by the Rice yellow mottle virus disease (RYMVD), a disease caused by Rice yellow mottle virus (RYMV) within the genus Sobemovirus; family Sobemoviridae. This study investigated the existence and distribution of resistance-breaking RYMV pathotype in the three major lowland rice catchment areas in Uganda. Four known rice accessions resistant to Rice yellow mottle virus (RYMV) namely; Gigante, Tog5672, Tog5674 and Tog5681, carrying resistant allele’s rymv1-2, rymv1-4 & RYMV3, rymv1-5 and rymv1-3, respectively, were tested for their response to different RYMV isolates. The isolates were collected from three major lowland rice catchment areas of Doho, Kibimba, and Olweny in Uganda. Out of 100 leaf samples collected from the field and assayed for RYMV and confirmed to be positive using RT-PCR, 83 isolates induced symptoms on IR64- the RYMV susceptible line. Seventy-seven (92.8%) isolates were able to overcome resistance in at least one of the four differential rice accessions, as confirmed by the presence of RYMV symptoms; while 6 (7.2%) isolates were asymptomatic. Variation in time (days) for symptom development post-inoculation (dpi) and AUDPC were observed. Symptoms appeared within 5-7 days on IR64; while it took on average 11, 18, 36, and 18 days to appear on Gigante, Tog5672, Tog5674 and Tog5681, respectively. The highest AUDPC was observed on IR64 (254.7); while the lowest was observed on Tog5681 (74.1). Two major patho-groups were observed; those that broke down resistance in Gigante only (25.3%) and Gigante & Tog5672 (33.7%). Five isolates from Doho (Budaka & Bugiri districts) and Kibimba (Butaleja district) catchment areas broke down RYMV resistance in three accessions i.e. (Tog5681, Gigante & Tog5672) and (Tog5674, Gigante & Tog5672), respectively. Resistance breaking isolates were confirmed in all  the three sampled catchment zones, however, Doho and Kibimba had some unique isolates that broke down resistance in accessions carrying resistance allele rymv 1-3 and rymv1-5 in addition to rymv1-2. Results from this study showed that RYMV isolates in Uganda can break down resistance conferred by the rymv1-2 resistance gene allele. However, accessions Tog5681 and Tog5674 seem to hold stable RYMV resistance and, thus are recommended for RYMV breeding.

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.

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