Characterization of the molecular mechanism of defective interfering RNA-mediated symptom attenuation in tombusvirus-infected plants
Characterization of the molecular mechanism of defective interfering RNA-mediated symptom attenuation in tombusvirus-infected plants
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DOI：
10.1128/jvi.72.7.6251-6256.1998
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发表时间：
1998-07-01
影响因子：
5.4
通讯作者：
Burgyán, J
中科院分区：
文献类型：
--
作者：
Havelda, Z;Szittya, G;Burgyán, J
不同的番茄丛矮病毒能够支持同源或异源缺陷型干扰RNA的复制，并且这些感染的植物通常表现出典型的减毒症状。然而，在一些辅助病毒-HI RNA组合中，接种的植物坏死，尽管它们含有高水平的DI RNA，表明DI RNA的积累和由此产生的基因组RNA复制的抑制不是症状减轻的直接原因。此外，已知在坏死症状发展中起关键作用的ORF 5的19-kDa蛋白产物在保护性同源DI RNA存在下和在非保护性异源DI RNA存在下在感染的植物中以相同水平积累。异源DI RNA保护病毒感染的植物免受系统性坏死的能力由辅助病毒基因组的5 ′-近端区域决定，呈现的结果表明，DI RNA介导的保护不通过特异性抑制19-kDa蛋白质表达来起作用，但更可能的是，保护性DI-辅助病毒组合中的Di RNA与病毒产物特异性相互作用，防止诱导坏死症状。
Different tombusviruses were able to support the replication of either homologous or heterologous defective interfering (DI) RNAs, and those infected plants usually developed typical attenuated symptoms. However, in some helper virus-HI RNA combinations the inoculated plants were necrotized, although they contained a high level of DI RNA, suggesting that the accumulation of DI RNA and the resulting suppression of genomic RNA replication were not directly responsible for the symptom attenuation. Moreover, the 19-kDa protein product of ORF 5, which is known to play a crucial role in necrotic symptom development, accumulated at the same level in the infected plants in the presence of protective homologous DI RNA and in the presence of nonprotective heterologous DI RNA, It was also demonstrated, by chimeric helper viruses, that the ability of heterologous DI RNA to protect the virus-infected plants against systemic necrosis is determined by the 5'-proximal region of the helper virus genome, The results presented suggest that DI RNA-mediated protection did not operate via the specific inhibition of 19-kDa protein expression but, more likely, Di RNAs in protective DI-helper virus combinations specifically interacted with viral products, preventing the induction of necrotic symptoms.