How Can Plant DNA Viruses Evade siRNA-Directed DNA Methylation and Silencing?

International Journal of Molecular Sciences

关键词: plant virus;    DNA virus;    geminivirus;    pararetrovirus;    silencing;    siRNA;    RNA-directed DNA methylation;    cytosine methylation;    silencing evasion;    suppressor protein;   

DOI  :  10.3390/ijms140815233

来源: mdpi

【 摘 要 】

Plants infected with DNA viruses produce massive quantities of virus-derived, 24-nucleotide short interfering RNAs (siRNAs), which can potentially direct viral DNA methylation and transcriptional silencing. However, growing evidence indicates that the circular double-stranded DNA accumulating in the nucleus for Pol II-mediated transcription of viral genes is not methylated. Hence, DNA viruses most likely evade or suppress RNA-directed DNA methylation. This review describes the specialized mechanisms of replication and silencing evasion evolved by geminiviruses and pararetoviruses, which rescue viral DNA from repressive methylation and interfere with transcriptional and post-transcriptional silencing of viral genes.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland