Tomato yellow leaf curl Sardinia virus can overcome transgene-mediated RNA silencing of two essential viral genes

• Published in: Journal of general virology Vol. 85; no. 6; pp. 1745 - 1749
• Main Authors: Noris, Emanuela, Lucioli, Alessandra, Tavazza, Raffaela, Caciagli, Piero, Accotto, Gian Paolo, Tavazza, Mario
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01.06.2004; Society for General Microbiology
• Subjects: Bemisia tabaci; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Geminiviridae - genetics; Geminivirus; Genes, Viral - genetics; Lycopersicon esculentum; Lycopersicon esculentum - virology; Microbiology; Miscellaneous; RNA Interference; Transgenes - physiology; Viral Proteins - genetics; Virology; Sardinia; Italy; Europe; Virus; Gene silencing; Tomato yellow leaf curl virus; Gene; Microbiology; RNA; Geminiviridae; Begomovirus; Virology
• ISSN: 0022-1317; 1465-2099
• DOI: 10.1099/vir.0.79944-0

1 Istituto di Virologia Vegetale, CNR, Strada delle Cacce 73, 10135 Torino, Italy 2 ENEA CR Casaccia, Settore Biotec, Via Anguillarese 301, 00060 Rome, Italy Correspondence Mario Tavazza tavazza_m{at}casaccia.enea.it To evaluate RNA silencing for the control of geminivirus infection, two classes of post-transcriptionally silenced (PTS) plants were tested using Tomato yellow leaf curl Sardinia virus (TYLCSV) Rep-210-transgenic plants, a sense x antisense hybrid and two multicopy sense lines. In both classes, PTS plants accumulated low or undetectable amounts of Rep-210 protein and mRNA but high amounts of Rep-210 small interfering RNAs. PTS plants were susceptible to TYLCSV when challenged by agroinoculation or using high viruliferous whitefly ( Bemisia tabaci ) pressure, although some plants were resistant at low whitefly pressure. Delayed infections were also observed, indicating that TYLCSV could overcome transgene silencing of rep and of the nested C4 gene. TYLCSV infection boosted transgene silencing but this did not lead to recovery. The data suggest that if the virus reaches a threshold level of expression/replication in the initially infected cells then virus spreading can no longer be prevented. These authors contributed equally to this work.