The Rep and C1 of Beet curly top Iran virus represent pathogenicity factors and induce hypersensitive response in Nicotiana benthamiana plants

Ebrahimi, Saeideh; Eini, Omid; Koolivand, Davoud; Varrelmann, Mark

doi:10.1007/s11262-022-01927-3

Cited by 6 publications

(5 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(Supplementary Figure S1a,b) [1,37,38]. Notably, C1 and Rep expression also led to necrotic speckles starting from 5 dpi and the necrotic phenotype gradually got stronger in the following days as previously reported [35].…”

Section: Phenotypic Analysis Of Transient Bctiv Gene Expression and S...supporting

confidence: 76%

“…The genes on the virion and complementary strand of the BCTIV replication intermediate (C1, C2, Rep, V1, V2, V3) based on Kaftarak isolate (GenBank: KP410285.1) were expressed via pDIVA binary vectors [35] for transient expression on GFP-expressing N. benthamiana 16C plants (Supplementary Figure S1a). The coding sequences of the C1, C2, Rep, and V2 genes were amplified with primers containing BamHI and XhoI restriction sites, using Q5 DNA polymerase (NEB).…”

Section: Plasmid Constructs For Transient Expressionmentioning

confidence: 99%

See 1 more Smart Citation

Beet Curly Top Iran Virus Rep and V2 Suppress Post-Transcriptional Gene Silencing via Distinct Modes of Action

Ebrahimi,

Eini,

Baßler

et al. 2023

Viruses

Self Cite

View full text Add to dashboard Cite

Beet curly top Iran virus (BCTIV) is a yield-limiting geminivirus belonging to the becurtovirus genus. The genome organization of BCTIV is unique such that the complementary strand of BCTIV resembles Mastrevirus, whereas the virion strand organization is similar to the Curtovirus genus. Geminiviruses are known to avoid the plant defense system by suppressing the RNA interference mechanisms both at the transcriptional gene silencing (TGS) and post-transcriptional gene silencing (PTGS) levels. Multiple geminivirus genes have been identified as viral suppressors of RNA silencing (VSR) but VSR activity remains mostly elusive in becurtoviruses. We found that BCTIV-V2 and -Rep could suppress specific Sense-PTGS mechanisms with distinct efficiencies depending on the nature of the silencing inducer and the target gene. Local silencing induced by GFP inverted repeat (IR) could not be suppressed by V2 but was partially reduced by Rep. Accordingly, we documented that Rep but not V2 could suppress systemic silencing induced by GFP-IR. In addition, we showed that the VSR activity of Rep was partly regulated by RNA-dependent RNA Polymerase 6 (RDR6), whereas the VSR activity of V2 was independent of RDR6. Domain mapping for Rep showed that an intact Rep protein was required for the suppression of PTGS. In summary, we showed that BCTIV-Rep and -V2 function as silencing suppressors with distinct modes of action.

show abstract

Section: Phenotypic Analysis Of Transient Bctiv Gene Expression and S...supporting

confidence: 76%

Section: Plasmid Constructs For Transient Expressionmentioning

confidence: 99%

Beet Curly Top Iran Virus Rep and V2 Suppress Post-Transcriptional Gene Silencing via Distinct Modes of Action

Ebrahimi,

Eini,

Baßler

et al. 2023

Viruses

Self Cite

View full text Add to dashboard Cite

show abstract

“…In a transient expression assay, BCTIV genes in tobacco revealed that Rep, together with C1, are the main pathogenicity factors which cause typical viral leaf curling symptoms. In addition, V2 caused a mild leaf curling, thickening, and asymmetric leaves, while V1, V3, and C2 had no clear effect on plant phenotype [ 26 ]. In another study, Bahari et al [ 27 ] mutated the BCTIV V2 and concluded that the gene plays a crucial role In viral pathogenicity and systemic movement by suppressing host post-transcriptional gene silencing (PTGS) mechanisms.…”

Section: Discussionmentioning

confidence: 99%

Development of Highly Efficient Resistance to Beet Curly Top Iran Virus (Becurtovirus) in Sugar Beet (B. vulgaris) via CRISPR/Cas9 System

Yıldırım

Kavas

Küçük

et al. 2023

IJMS

View full text Add to dashboard Cite

Beet Curly Top Iran Virus (BCTIV, Becurtovirus) is a dominant and widespread pathogen responsible for great damage and yield reduction in sugar beet production in the Mediterranean and Middle East. CRISPR-based gene editing is a versatile tool that has been successfully used in plants to improve resistance against many viral pathogens. In this study, the efficiency of gRNA/Cas9 constructs targeting the expressed genes of BCTIV was assessed in sugar beet leaves by their transient expression. Almost all positive control sugar beets revealed systemic infection and severe disease symptoms (90%), with a great biomass reduction (68%) after BCTIV agroinoculation. On the other hand, sugar beets co-agronioculated with BCTIV and gRNA/Cas9 indicated much lower systemic infection (10–55%), disease symptoms and biomass reduction (13–45%). Viral inactivation was also verified by RCA and qPCR assays for gRNA/Cas9 treated sugar beets. PCR-RE digestion and sequencing assays confirmed the gRNA/Cas9-mediated INDEL mutations at the target sites of the BCTIV genome and represented high efficiencies (53–88%), especially for those targeting BCTIV’s movement gene and its overlapping region between capsid and ssDNA regulator genes. A multiplex CRISPR approach was also tested. The most effective four gRNAs targeting all the genes of BCTIV were cloned into a Cas9-containing vector and agroinoculated into virus-infected sugar beet leaves. The results of this multiplex CRISPR system revealed almost complete viral resistance with inhibition of systemic infection and mutant escape. This is the first report of CRSIPR-mediated broad-spectrum resistance against Becurtovirus in sugar beet.

show abstract

“…For unbiased investigation of the genes potentially responsible for VSR all verified ORFs of BCTIV (C1, C2, C4, Rep, V1, V2, V3) in pDIVA and/or pG104 binary vectors (Ebrahimi et al 2022) were examined on 16C plants (Supplementary Figure 1). The coding sequences of the C1, C2, Rep, and V2 genes were amplified with primers containing BamHI and XhoI restriction cut sites (Table 1), using Q5 polymerase (NEB).…”

Section: Methodsmentioning

confidence: 99%

Beet curly top Iran virus Rep and V2 gene work as suppressors of post-transcriptional gene silencing through separate mechanisms

Ebrahimi

Baßler

Eini

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

Beet curly top Iran Virus (BCTIV) is a yield-limiting geminivirus belonging to the becurtovirus genus. The genome organization of BCTIV is unique in a way that the complementary strand of BCTIV resembles mastreviruses, whereas the virion strand organization is close to curtoviruses. Geminiviruses are known to avoid the plant defense system by suppressing the RNA interference mechanisms both at the transcriptional gene silencing (TGS) and post-transcriptional gene silencing (PTGS) level. Multiple geminivirus genes have been identified as viral suppressors of RNA silencing (VSR) but the genes underlying VSR activity remain elusive in becurtoviruses. We performed an unbiased screen on each individual BCTIV gene for VSR activity based on three different PTGS experimental setups with transient silencing inducers on stably GFP-expressing Nicotiana benthamiana (16C) and on transiently GFP expressing wild-type Nicotiana benthamiana (WT). We found that only V2 and Rep were able to suppress specific PTGS mechanisms. BCTIV-V2 could suppress S-PTGS more efficiently than BCTIV-Rep when there is transient GFP expression. However, Rep but not V2 could suppress S-PTGS when GFP is only stably expressed by 16C. Furthermore, neither V2 nor Rep could suppress local PTGS induced by inverted repeat targeting GFP (GFP-IR) when GFP is only stably expressed by 16C. Nevertheless, Rep suppressed the systemic silencing induced by GFP-IR in 16C plants. BCTIV-Rep inhibits silencing by mitigating sRNA production, whereas BCTIV-V2 does not alter sRNA, suggesting that Rep and V2 have distinct modes of action. Further characterization of BCTIV-Rep by deletional mutagenesis implicated that multiple domains are required for silencing suppressor activity of Rep. This is the first study revealing the genes responsible for silencing suppression in a becurtovirus and implicating their mode of action.

show abstract

The Rep and C1 of Beet curly top Iran virus represent pathogenicity factors and induce hypersensitive response in Nicotiana benthamiana plants

Cited by 6 publications

References 50 publications

Beet Curly Top Iran Virus Rep and V2 Suppress Post-Transcriptional Gene Silencing via Distinct Modes of Action

Beet Curly Top Iran Virus Rep and V2 Suppress Post-Transcriptional Gene Silencing via Distinct Modes of Action

Development of Highly Efficient Resistance to Beet Curly Top Iran Virus (Becurtovirus) in Sugar Beet (B. vulgaris) via CRISPR/Cas9 System

Beet curly top Iran virus Rep and V2 gene work as suppressors of post-transcriptional gene silencing through separate mechanisms

Contact Info

Product

Resources

About