Deep sequencing-based transcriptome profiling reveals comprehensive insights into the responses of Nicotiana benthamiana to beet necrotic yellow vein virus infections containing or lacking RNA4.

Huiyan Fan,Chenggui Han,Jialin Yu,Ying Wang,Yongliang Zhang,Dawei Li,Xianbing Wang,Haiwen Sun

doi:10.1371/journal.pone.0085284

Huiyan Fan, Chenggui Han + Show 6 more

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https://doi.org/10.1371/journal.pone.0085284

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Journal: PloS one	Publication Date: Jan 9, 2014
Citations: 88	License type: CC BY 4.0

Affiliation: China Agricultural University

Abstract

Background Beet necrotic yellow vein virus (BNYVV), encodes either four or five plus-sense single stranded RNAs and is the causal agent of sugar beet rhizomania disease, which is widely distributed in most regions of the world. BNYVV can also infect Nicotiana benthamiana systemically, and causes severe curling and stunting symptoms in the presence of RNA4 or mild symptoms in the absence of RNA4.ResultsConfocal laser scanning microscopy (CLSM) analyses showed that the RNA4-encoded p31 protein fused to the red fluorescent protein (RFP) accumulated mainly in the nuclei of N. benthamiana epidermal cells. This suggested that severe RNA4-induced symptoms might result from p31-dependent modifications of the transcriptome. Therefore, we used next-generation sequencing technologies to analyze the transcriptome profile of N. benthamiana in response to infection with different isolates of BNYVV. Comparisons of the transcriptomes of mock, BN3 (RNAs 1+2+3), and BN34 (RNAs 1+2+3+4) infected plants identified 3,016 differentially expressed transcripts, which provided a list of candidate genes that potentially are elicited in response to virus infection. Our data indicate that modifications in the expression of genes involved in RNA silencing, ubiquitin-proteasome pathway, cellulose synthesis, and metabolism of the plant hormone gibberellin may contribute to the severe symptoms induced by RNA4 from BNYVV.ConclusionsThese results expand our understanding of the genetic architecture of N. benthamiana as well as provide valuable clues to identify genes potentially involved in resistance to BNYVV infection. Our global survey of gene expression changes in infected plants reveals new insights into the complicated molecular mechanisms underlying symptom development, and aids research into new strategies to protect crops against viruses.

Highlights

Rhizomania is a soil-borne disease caused by Beet necrotic yellow vein virus (BNYVV) and is a major threat to sugar beet production throughout the world [1]
Consistent with previous studies, our results have shown that the Chinese isolate BN34 induces very severe symptoms, including stunting and downward curling of the upper leaves by 12–14 days post-inoculation, whereas infection by BN3 results in mild symptoms in N. benthamiana (Figure 1A)
In order to determine the subcellular localization of the p31 protein, plasmids harboring the p31protein fused with the red fluorescent protein (RFP) at the C-terminus (P31-RFP) or the Nterminus (RFP-P31) were transiently introduced into N. benthamiana leaf cells via agro-infiltration

Summary

Introduction

Rhizomania is a soil-borne disease caused by Beet necrotic yellow vein virus (BNYVV) and is a major threat to sugar beet production throughout the world [1]. Compared with RNA3, RNA4 has minor effects on leaf symptoms on Tetragania expansa and some Beta species [10], but RNA4-encoded p31 is required for efficient vector transmission and root-specific suppression of virus-induced gene silencing [10,11]. Beet necrotic yellow vein virus (BNYVV), encodes either four or five plus-sense single stranded RNAs and is the causal agent of sugar beet rhizomania disease, which is widely distributed in most regions of the world. BNYVV can infect Nicotiana benthamiana systemically, and causes severe curling and stunting symptoms in the presence of RNA4 or mild symptoms in the absence of RNA4

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