Genetic analyses of BaMMV/BaYMV resistance in barley accession HOR4224 result in the identification of an allele of the translation initiation factor 4e (Hv-eIF4E) exclusively effective against Barley mild mosaic virus (BaMMV)

With the aim to characterize plant and viral factors involved in the molecular interactions between plants and potyviruses, a Lettuce mosaic virus (LMV)-Arabidopsis thaliana pathosystem was developed. Screening of Arabi-dopsis accessions with LMV isolates indicated the existence of a large variability in the outcome of the interaction, allowing the classification of Arabidopsis accessions into seven susceptibility groups. Using a reverse genetic approach, the genome-linked protein of LMV, a multifunc-tional protein shown to be involved in viral genome amplification and movement of potyviruses, was established as the viral determinant responsible for the ability to overcome the resistance of the Niederzenz accession to LMV-0. Preliminary genetic analyses from F2 and recombinant inbred lines available between susceptible and resistant Arabidopsis accessions revealed the existence of at least three resistance phenotypes to LMV with different genetic bases. One dominant resistance gene, designated LLM1, involved in blocking the replication or cell-to-cell movement of the LMV-0 isolate in the Columbia accession, was mapped to chromosome I and shown to be linked to the marker nga280. At the same time, genetic analyses of segregating F2 populations were consistent with the restriction of the systemic movement of the LMV-AF199 isolate in Columbia being controlled by two dominant genes and with the complete resistance to all tested LMV isolates of the Cape Verde islands (Cvi) accession being conferred by a single recessive resistance gene. Sequencing of the eu-karyotic translation initiation factor 4E genes from the different LMV-resistant Arabidopsis accessions showed that these factors are not directly involved in the characterized resistance phenotypes.

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Bean common mosaic virus Isolate Exhibits a Novel Pathogenicity Profile in Common Bean, Overcoming the bc-3 Resistance Allele Coding for the Mutated eIF4E Translation Initiation Factor

Phytopathology ◽

10.1094/phyto-04-15-0108-r ◽

2015 ◽

Vol 105 (11) ◽

pp. 1487-1495 ◽

Cited By ~ 18

Author(s):

Xue Feng ◽

James R. Myers ◽

Alexander V. Karasev

Keyword(s):

Common Bean ◽

Mosaic Virus ◽

Translation Initiation ◽

Resistance Genes ◽

Strain Analysis ◽

Bean Common Mosaic Virus ◽

Translation Initiation Factor ◽

Initiation Factor ◽

Resistance Allele ◽

Eukaryotic Translation

Resistance against Bean common mosaic virus (BCMV) in Phaseolus vulgaris is governed by six recessive resistance alleles at four loci. One of these alleles, bc-3, is able to protect P. vulgaris against all BCMV strains and against other potyviruses; bc-3 was identified as the eIF4E allele carrying mutated eukaryotic translation initiation factor gene. Here, we characterized a novel BCMV isolate 1755a that was able to overcome bc-2 and bc-3 alleles in common bean. Thus, it displayed a novel pattern of interactions with resistance genes in P. vulgaris, and was assigned to a new pathogroup, PG-VIII. The IVT7214 cultivar supporting the replication of BCMV-1755a was found to have the intact homozygous bc-3 cleaved amplified polymorphic sequences marker and corresponding mutations in the eIF4E allele that confer resistance to BCMV isolates from all other pathogroups as well as to other potyviruses. The VPg protein of 1755a had seven amino acid substitutions relative to VPgs of other BCMV isolates unable to overcome bc-3. The 1755a genome was found to be a recombinant between NL1, US1 (both PG-I), and a yet unknown BCMV strain. Analysis of the recombination patterns in the genomes of NL1 and US1 (PG-I), NY15P (PG-V), US10 and RU1-OR (PG-VII), and 1755a (PG-VIII), indicated that P1/HC-Pro cistrons of BCMV strains may interact with most resistance genes. This is the first report of a BCMV isolate able to overcome the bc-3 resistance allele, suggesting that the virus has evolved mechanisms to overcome multiple resistance genes available in common bean.

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Targeted Knockout of Eukaryotic Translation Initiation Factor 4E Confers Bymovirus Resistance in Winter Barley

Frontiers in Genome Editing ◽

10.3389/fgeed.2021.784233 ◽

2021 ◽

Vol 3 ◽

Author(s):

Robert Eric Hoffie ◽

Ingrid Otto ◽

Dragan Perovic ◽

Nagaveni Budhagatapalli ◽

Antje Habekuß ◽

...

Keyword(s):

Mosaic Virus ◽

Translation Initiation ◽

Winter Barley ◽

Translation Initiation Factor ◽

Initiation Factor ◽

Yellow Mosaic Virus ◽

Eukaryotic Translation Initiation Factor ◽

Eukaryotic Translation ◽

Barley Yellow Mosaic Virus ◽

Eukaryotic Translation Initiation

The Eukaryotic Translation Initiation Factor 4E (EIF4E) is a well-known susceptibility factor for potyvirus infections in many plant species. The barley yellow mosaic virus disease, caused by the bymoviruses Barley yellow mosaic virus (BaYMV) and Barley mild mosaic virus (BaMMV), can lead to yield losses of up to 50% in winter barley. In autumn, the roots of young barley plants are infected by the soil-borne plasmodiophoraceous parasite Polymyxa graminis L. that serves as viral vector. Upon viral establishment and systemic spreading into the upper parts of the plants, yellow mosaics occur as first symptoms on leaves. In the further course of plant development, the disease entails leaf necrosis and increased susceptibility to frost damage. Thanks to the rym4 and rym5 allelic variants of the HvEIF4E gene, more than two thirds of current European winter barley cultivars are resistant to BaYMV and BaMMV. However, several strains of BaYMV and BaMMV have already overcome rym4- and rym5-mediated resistance. Accordingly, new resistance-conferring alleles are needed for barley breeding. Therefore, we performed targeted mutagenesis of the EIF4E gene by Cas9 endonuclease in BaMMV/BaYMV-susceptible winter barley cv. “Igri”. Small insertions were generated, resulting in a shift of the translational reading frame, thereby causing the loss-of-function of EIF4E. The mutations occurred in the homozygous state already in the primary mutants. Their progeny proved invariably homozygous and fully resistant to mechanical inoculation with BaMMV. EIF4E knockout plants showed normal growth habit and produced grains, yet exhibited a yield penalty.

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Adaptation of Lettuce mosaic virus to Catharanthus roseus Involves Mutations in the Central Domain of the VPg

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-10-13-0320-r ◽

2014 ◽

Vol 27 (5) ◽

pp. 491-497 ◽

Cited By ~ 9

Author(s):

Laurence Svanella-Dumas ◽

Eric Verdin ◽

Chantal Faure ◽

Sylvie German-Retana ◽

Patrick Gognalons ◽

...

Keyword(s):

Mosaic Virus ◽

Catharanthus Roseus ◽

Translation Initiation ◽

Translation Initiation Factor ◽

Initiation Factor ◽

Terminal Part ◽

Lettuce Mosaic Virus ◽

Eukaryotic Translation ◽

Illumina Deep Sequencing ◽

Eukaryotic Translation Initiation

An isolate of Lettuce mosaic virus (LMV, a Potyvirus) infecting Madagascar periwinckle (Catharanthus roseus) was identified and characterized by Illumina deep sequencing. LMV-Cr has no close affinities to previously sequenced LMV isolates and represents a novel, divergent LMV clade. Inoculation experiments with other representative LMV isolates showed that they are unable to infect C. roseus, which was not known to be a host for LMV. However, three C. roseus variants of one of these isolates, LMV-AF199, could be selected and partially or completely sequenced. These variants are characterized by the accumulation of mutations affecting the C-terminal part of the cylindrical inclusion (CI) helicase and the central part of the VPg. In particular, a serine to proline mutation at amino acid 143 of the VPg was observed in all three independently selected variants and is also present in the LMV-Cr isolate, making it a prime candidate as a host-range determinant. Other mutations at VPg positions 65 and 144 could also contribute to the ability to infect C. roseus. Inoculation experiments involving a recombinant LMV expressing a permissive lettuce eukaryotic translation initiation factor 4E (eIF4E) suggest that eIF4E does not contribute to the interaction of most LMV isolates with C. roseus.

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The Same Allele of Translation Initiation Factor 4E Mediates Resistance Against Two Potyvirus spp. in Pisum sativum

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-20-9-1075 ◽

2007 ◽

Vol 20 (9) ◽

pp. 1075-1082 ◽

Cited By ~ 50

Author(s):

M. Bruun-Rasmussen ◽

I. S. Møller ◽

G. Tulinius ◽

J. K. R. Hansen ◽

O. S. Lund ◽

...

Keyword(s):

Pisum Sativum ◽

Mosaic Virus ◽

Resistance Gene ◽

Translation Initiation ◽

Recessive Gene ◽

Translation Initiation Factor ◽

Initiation Factor ◽

Yellow Mosaic Virus ◽

White Lupin ◽

Coding Region

Pathogenicity of two sequenced isolates of Bean yellow mosaic virus (BYMV) was established on genotypes of Pisum sativum L. reported to carry resistance genes to BYMV and other potyviruses. Resistance to the white lupin strain of BYMV (BYMV-W) is inherited as a recessive gene named wlv that maps to linkage group VI together with other Potyvirus resistances. One of these, sbm1, confers resistance to strains of Pea seedborne mosaic virus and previously has been identified as a mutant allele of the eukaryotic translation initiation factor 4E gene (eIF4E). Sequence comparison of eIF4E from BYMV-W-susceptible and –resistant P. sativum genotypes revealed a polymorphism correlating with the resistance profile. Expression of eIF4E from susceptible plants in resistant plants facilitated BYMV-W infection in inoculated leaves. When cDNA of BYMV-W was agroinoculated, resistance mediated by the wlv gene frequently was overcome, and virus from these plants had a codon change causing an Arg to His change at position 116 of the predicted viral genome-linked protein (VPg). Accordingly, plants carrying the wlv resistance gene were infected upon inoculation with BYMV-W derived from cDNA with a His codon at position 116 of the VPg coding region. These results suggested that VPg determined pathogenicity on plants carrying the wlv resistance gene and that wlv corresponded to the sbm1 allele of eIF4E.

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