Dataset Information

Identification and characterization of a new geminivirus from soybean plants and determination of V2 as a pathogenicity factor and silencing suppressor.

ABSTRACT:

Background

Soybean is one of the four major crops in China. The occurrence of viruses in soybean causes significant economic losses.

Results

In this study, the soybean leaves from stay-green plants showing crinkle were collected for metatranscriptomic sequencing. A novel geminivirus, tentatively named soybean geminivirus A (SGVA), was identified in soybean stay-green plants. Sequence analysis of the full-length SGVA genome revealed a genome of 2762 nucleotides that contain six open reading frames. Phylogenetic analyses revealed that SGVA was located adjacent to the clade of begomoviruses in both the full genome-based and C1-based phylogenetic tree, while in the CP-based phylogenetic tree, SGVA was located adjacent to the clade of becurtoviruses. SGVA was proposed as a new recombinant geminivirus. Agroinfectious clone of SGVA was constructed. Typical systemic symptoms of curly leaves were observed at 11 dpi in Nicotiana benthamiana plants and severe dwarfism was observed after 3 weeks post inoculation. Expression of the SGVA encoded V2 and C1 proteins through a potato virus X (PVX) vector caused severe symptoms in N. benthamiana. The V2 protein inhibited local RNA silencing in co-infiltration assays in GFP transgenic 16C N. benthamiana plants. Further study revealed mild symptoms in N. benthamiana plants inoculated with SGVA-ZZ _V2-STOP and SGVA-ZZ _V2-3738AA mutants. Both the relative viral DNA and CP protein accumulation levels significantly decreased when compared with SGVA-inoculated plants.

Conclusions

This work identified a new geminivirus in soybean stay-green plants and determined V2 as a pathogenicity factor and silencing suppressor.

SUBMITTER: Li Q

PROVIDER: S-EPMC9308217 | biostudies-literature | 2022 Jul

REPOSITORIES: biostudies-literature

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Publications

Identification and characterization of a new geminivirus from soybean plants and determination of V2 as a pathogenicity factor and silencing suppressor.

Li Qinglun Q Zhang Yuyang Y Lu Weiguo W Han Xiaoyu X Yang Lingling L Shi Yajuan Y Li Honglian H Chen Linlin L Liu Yiqing Y Yang Xue X Shi Yan Y

BMC plant biology 20220722 1

<h4>Background</h4>Soybean is one of the four major crops in China. The occurrence of viruses in soybean causes significant economic losses.<h4>Results</h4>In this study, the soybean leaves from stay-green plants showing crinkle were collected for metatranscriptomic sequencing. A novel geminivirus, tentatively named soybean geminivirus A (SGVA), was identified in soybean stay-green plants. Sequence analysis of the full-length SGVA genome revealed a genome of 2762 nucleotides that contain six ope ...[more]

PMID: 35869422

Similar Datasets

Project description:Cytosine DNA methylation is a conserved epigenetic silencing mechanism that defends against biotic stresses such as geminivirus infection. As a countermeasure, geminiviruses encode proteins that inhibit methylation and transcriptional gene silencing (TGS). Previous studies showed that V2 protein of Tomato yellow leaf curl virus (TYLCV) functions as a TGS suppressor. However, how V2 mediates TGS suppression remains unknown. Here we show that V2 interacts directly with a Nicotiana benthamiana histone deacetylase 6 (NbHDA6), a homolog of Arabidopsis HDA6 (AtHDA6), known to be involved in gene silencing in cooperation with methyltransferase 1 (MET1). NbHDA6 genetically complemented a late-flowering phenotype and restored histone deacetylation of an AtHDA6 mutant. Furthermore, our investigation showed that NbHDA6 displayed histone deacetylase enzymatic activity, which was not inhibited by V2. Genetic analysis revealed that silencing of NbHDA6 expression resulted in enhanced susceptibility to TYLCV infection. In addition, methylation-sensitive PCR and bisulfite sequencing analysis showed that silencing of NbHDA6 expression caused reduced DNA methylation of the viral genome in infected plants. HDA6 was previously shown to recruit and physically interact with MET1 to function in gene silencing. Using competitive pulldown and coimmunoprecipitation assays, we demonstrated that V2 did not interact but competed with NbMET1 for direct binding to NbHDA6. These findings suggest that V2 interacts with host HDA6 and interferes with the recruitment of MET1 by HDA6, resulting in decreased methylation of the viral DNA genome by TGS with a concomitant increase in host susceptibility to TYLCV infection.IMPORTANCE Plants employ repressive viral genome methylation as an epigenetic defense against geminiviruses. In turn, geminiviruses encode proteins that inhibit methylation by TGS. Previous studies showed that TYLCV V2 can efficiently suppress TGS, but the mechanism remains unknown. We showed that V2 interacted with NbHDA6 but did not inhibit its enzymatic activity. As HDA6 is known to be involved in gene silencing in cooperation with MET1, we explored the relationship between V2, NbMET1, and NbHDA6. Our investigation showed that V2 did not interact but competed with NbMET1 for direct binding to NbHDA6. To our knowledge, this is the first report that viral proteins inhibit TGS by interacting with histone deacetylase but not by blocking the methyl cycle. This work provides an additional mechanism for TGS suppression by geminiviruses.

Dataset Information

Identification and characterization of a new geminivirus from soybean plants and determination of V2 as a pathogenicity factor and silencing suppressor.

Background

Results

Conclusions

Publications

Identification and characterization of a new geminivirus from soybean plants and determination of V2 as a pathogenicity factor and silencing suppressor.

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