RNA4-encoded p31 of beet necrotic yellow vein virus is involved in efficient vector transmission, symptom severity and silencing suppression in roots
RNA4-encoded p31 of beet necrotic yellow vein virus is involved in efficient vector transmission, symptom severity and silencing suppression in roots
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DOI：
10.1099/vir.0.82720-0
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发表时间：
2007-05-01
影响因子：
3.8
通讯作者：
Tamada, Tetsuo
中科院分区：
文献类型：
--
作者：
Rahim, Muhammad Danial;Andika, Ida Bagus;Tamada, Tetsuo
甜菜坏死黄脉病毒（BNYVV）的RNA3和RNA4不是病毒增殖所必需的，但与甜菜根中的载体介导的感染和疾病发展有关。在此，证明了RNA4在病毒传播、毒力和RNA沉默抑制中的独特作用。突变分析表明，RNA4编码的p31开放阅读框（ORF）参与了有效的载体传播和轻微增强的症状表达在一些β物种。没有观察到RNA4对感染组织中病毒积累的影响。此外，p31 ORF参与了BNYVV在本氏烟草植物中诱导严重症状而不影响病毒RNA积累。与此相反，RNA3编码的p25，以前确定为甜菜症状诱导的主要贡献者，对N没有这种影响。本萨米亚纳在两种不同的沉默抑制试验中，p31和p25都不能抑制叶片中的RNA沉默，但p31的存在增强了根中的沉默抑制子活性，而不改变病毒RNA积累。因此，BNYVV p31在有效的载体传播、增强的症状表达和根特异性沉默抑制中起多功能作用。
RNA3 and RNA4 of beet necrotic yellow vein virus (BNYVV) are not essential for virus multiplication, but are associated with vector-mediated infection and disease development in sugar beet roots. Here, a unique role for RNA4 in virus transmission, virulence and RNA silencing suppression was demonstrated. Mutagenic analysis revealed that the RNA4-encoded p31 open reading frame (ORF) was involved in efficient vector transmission and slight enhancement of symptom expression in some Beta species. No effects of RNA4 on virus accumulation in infected tissue were observed. Furthermore, the p31 ORF was involved in the induction of severe symptoms by BNYVV in Nicotiana benthamiana plants without affecting viral RNA accumulation. In contrast, RNA3-encoded p25, previously identified as a major contributor to symptom induction in sugar beet, had no such effect on N. benthamiana. In two different silencing suppression assays, neither p31 nor p25 was able to suppress RNA silencing in leaves, but the presence of p31 enhanced a silencing suppressor activity in roots without alteration in viral RNA accumulation. Thus, BNYVV p31 plays a multifunctional role in efficient vector transmission, enhanced symptom expression and root-specific silencing suppression.